From 246b65c7228075a36b112eb3fb1d3c248e70d5bc Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Thu, 25 Mar 2021 15:34:09 -0400
Subject: [PATCH 1/7] fix: Merge compatible definitions in union types

Most validation keywords apply to only one of the basic types, so a
"string" type and an "array" type can share a definition without
colliding as a ["string", "array"] type, as long as they don't have any
incompatibilities with each other. Modify UnionTypeFormatter to collapse
these disjoint types into a single definition, without using anyOf.
---
 src/TypeFormatter/UnionTypeFormatter.ts | 13 +++++++++++++
 src/Utils/mergeDefinitions.ts           | 25 +++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 src/Utils/mergeDefinitions.ts

diff --git a/src/TypeFormatter/UnionTypeFormatter.ts b/src/TypeFormatter/UnionTypeFormatter.ts
index a8f553fea..49786aba0 100644
--- a/src/TypeFormatter/UnionTypeFormatter.ts
+++ b/src/TypeFormatter/UnionTypeFormatter.ts
@@ -4,6 +4,7 @@ import { SubTypeFormatter } from "../SubTypeFormatter";
 import { BaseType } from "../Type/BaseType";
 import { UnionType } from "../Type/UnionType";
 import { TypeFormatter } from "../TypeFormatter";
+import { mergeDefinitions } from "../Utils/mergeDefinitions";
 import { uniqueArray } from "../Utils/uniqueArray";
 
 export class UnionTypeFormatter implements SubTypeFormatter {
@@ -45,6 +46,18 @@ export class UnionTypeFormatter implements SubTypeFormatter {
             }
         }
 
+        for (let idx = 0; idx < flattenedDefinitions.length - 1; idx++) {
+            for (let comp = idx + 1; comp < flattenedDefinitions.length; ) {
+                const merged = mergeDefinitions(flattenedDefinitions[idx], flattenedDefinitions[comp]);
+                if (merged) {
+                    flattenedDefinitions[idx] = merged;
+                    flattenedDefinitions.splice(comp, 1);
+                } else {
+                    comp++;
+                }
+            }
+        }
+
         return flattenedDefinitions.length > 1
             ? {
                   anyOf: flattenedDefinitions,
diff --git a/src/Utils/mergeDefinitions.ts b/src/Utils/mergeDefinitions.ts
new file mode 100644
index 000000000..4c3caf0de
--- /dev/null
+++ b/src/Utils/mergeDefinitions.ts
@@ -0,0 +1,25 @@
+import { Definition } from "../Schema/Definition";
+import { uniqueArray } from "./uniqueArray";
+
+/**
+ * Attempt to merge two disjoint definitions into one. Definitions are disjoint
+ * (and therefore mergeable) if all of the following are true:
+ * 1) Each has a 'type' property, and they share no types in common,
+ * 2) The cross-type validation properties 'enum' and 'const' are not on either definition, and
+ * 3) The two definitions have no properties besides 'type' in common.
+ *
+ * Returns the merged definition, or null if the two defs were not disjoint.
+ */
+export function mergeDefinitions(def1: Definition, def2: Definition): Definition | null {
+    const { type: type1, ...props1 } = def1;
+    const { type: type2, ...props2 } = def2;
+    const types = [type1!, type2!].flat();
+    if (!type1 || !type2 || uniqueArray(types).length !== types.length) {
+        return null;
+    }
+    const keys = [Object.keys(props1), Object.keys(props2)].flat();
+    if (keys.includes("enum") || keys.includes("const") || uniqueArray(keys).length !== keys.length) {
+        return null;
+    }
+    return { type: types, ...props1, ...props2 };
+}

From 6b0e19b49298abf1c2571d9ebe5c2a8c51272285 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Thu, 25 Mar 2021 17:42:24 -0400
Subject: [PATCH 2/7] Update src/Utils/mergeDefinitions.ts

Change the array.flat() call to use spread notation, since both members are guaranteed to be arrays (unlike the types call, above). Thanks for the suggestion, @domoritz!

Co-authored-by: Dominik Moritz <domoritz@gmail.com>
---
 src/Utils/mergeDefinitions.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Utils/mergeDefinitions.ts b/src/Utils/mergeDefinitions.ts
index 4c3caf0de..749392a27 100644
--- a/src/Utils/mergeDefinitions.ts
+++ b/src/Utils/mergeDefinitions.ts
@@ -17,7 +17,7 @@ export function mergeDefinitions(def1: Definition, def2: Definition): Definition
     if (!type1 || !type2 || uniqueArray(types).length !== types.length) {
         return null;
     }
-    const keys = [Object.keys(props1), Object.keys(props2)].flat();
+    const keys = [...Object.keys(props1), ...Object.keys(props2)];
     if (keys.includes("enum") || keys.includes("const") || uniqueArray(keys).length !== keys.length) {
         return null;
     }

From 109b78e4296b2f21975527064a147d44b7c10e87 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Fri, 26 Mar 2021 00:20:43 -0400
Subject: [PATCH 3/7] Updating test snapshots; fixing reachability tests

The vega-lite test originally worked after updating the snapshot, but
there was a broken reference that got mistakenly purged by
removeUnreachable (which assumed that any definition would
only ever have a single property that could hold references).

Added a validation check to vega-lite.test to register the failure,
updated addReachable to check all possible properties (unless
$ref is set; the spec says that everything else gets ignored in
that case).
---
 src/Utils/removeUnreachable.ts                |   57 +-
 .../type-mapped-double-exclude/schema.json    |   24 +-
 test/valid-data/type-union/schema.json        |   16 +-
 test/vega-lite.test.ts                        |    9 +
 test/vega-lite/schema.json                    | 1122 ++++++++---------
 5 files changed, 567 insertions(+), 661 deletions(-)

diff --git a/src/Utils/removeUnreachable.ts b/src/Utils/removeUnreachable.ts
index 1619fc3f9..8619e5638 100644
--- a/src/Utils/removeUnreachable.ts
+++ b/src/Utils/removeUnreachable.ts
@@ -20,38 +20,45 @@ function addReachable(
         }
         reachable.add(typeName);
         addReachable(definitions[typeName], definitions, reachable);
-    } else if (definition.anyOf) {
-        for (const def of definition.anyOf) {
-            addReachable(def, definitions, reachable);
+    } else {
+        if (definition.anyOf) {
+            for (const def of definition.anyOf) {
+                addReachable(def, definitions, reachable);
+            }
         }
-    } else if (definition.allOf) {
-        for (const def of definition.allOf) {
-            addReachable(def, definitions, reachable);
+        if (definition.allOf) {
+            for (const def of definition.allOf) {
+                addReachable(def, definitions, reachable);
+            }
         }
-    } else if (definition.oneOf) {
-        for (const def of definition.oneOf) {
-            addReachable(def, definitions, reachable);
+        if (definition.oneOf) {
+            for (const def of definition.oneOf) {
+                addReachable(def, definitions, reachable);
+            }
         }
-    } else if (definition.not) {
-        addReachable(definition.not, definitions, reachable);
-    } else if (definition.type === "object") {
-        for (const prop in definition.properties || {}) {
-            const propDefinition = definition.properties![prop];
-            addReachable(propDefinition, definitions, reachable);
+        if (definition.not) {
+            addReachable(definition.not, definitions, reachable);
         }
+        if (definition.type === "object" || (Array.isArray(definition.type) && definition.type.includes("object"))) {
+            for (const prop in definition.properties || {}) {
+                const propDefinition = definition.properties![prop];
+                addReachable(propDefinition, definitions, reachable);
+            }
 
-        const additionalProperties = definition.additionalProperties;
-        if (additionalProperties) {
-            addReachable(additionalProperties, definitions, reachable);
+            const additionalProperties = definition.additionalProperties;
+            if (additionalProperties) {
+                addReachable(additionalProperties, definitions, reachable);
+            }
         }
-    } else if (definition.type === "array") {
-        const items = definition.items;
-        if (isArray(items)) {
-            for (const item of items) {
-                addReachable(item, definitions, reachable);
+        if (definition.type === "array" || (Array.isArray(definition.type) && definition.type.includes("array"))) {
+            const items = definition.items;
+            if (isArray(items)) {
+                for (const item of items) {
+                    addReachable(item, definitions, reachable);
+                }
+            } else if (items) {
+                addReachable(items, definitions, reachable);
             }
-        } else if (items) {
-            addReachable(items, definitions, reachable);
         }
     }
 }
diff --git a/test/valid-data/type-mapped-double-exclude/schema.json b/test/valid-data/type-mapped-double-exclude/schema.json
index 99b1a9a9b..16e42b471 100644
--- a/test/valid-data/type-mapped-double-exclude/schema.json
+++ b/test/valid-data/type-mapped-double-exclude/schema.json
@@ -6,25 +6,17 @@
       "additionalProperties": false,
       "properties": {
         "bar": {
-          "anyOf": [
-            {
-              "description": "Bar",
-              "type": "number"
-            },
-            {
-              "type": "null"
-            }
+          "description": "Bar",
+          "type": [
+            "number",
+            "null"
           ]
         },
         "foo": {
-          "anyOf": [
-            {
-              "description": "Foo",
-              "type": "number"
-            },
-            {
-              "type": "null"
-            }
+          "description": "Foo",
+          "type": [
+            "number",
+            "null"
           ]
         }
       },
diff --git a/test/valid-data/type-union/schema.json b/test/valid-data/type-union/schema.json
index 043850f85..70d8e1b8e 100644
--- a/test/valid-data/type-union/schema.json
+++ b/test/valid-data/type-union/schema.json
@@ -12,16 +12,12 @@
           ]
         },
         "var2": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "number"
-              },
-              "type": "array"
-            }
+          "items": {
+            "type": "number"
+          },
+          "type": [
+            "string",
+            "array"
           ]
         },
         "var3": {
diff --git a/test/vega-lite.test.ts b/test/vega-lite.test.ts
index 3cbc5ce2b..529707330 100644
--- a/test/vega-lite.test.ts
+++ b/test/vega-lite.test.ts
@@ -3,6 +3,8 @@ import { resolve } from "path";
 import { Config } from "../src/Config";
 import { createGenerator } from "./utils";
 import stringify from "json-stable-stringify";
+import Ajv from "ajv";
+import addFormats from "ajv-formats";
 
 describe("vega-lite", () => {
     it("schema", () => {
@@ -18,6 +20,13 @@ describe("vega-lite", () => {
         const schema = generator.createSchema(type);
         const schemaFile = resolve("test/vega-lite/schema.json");
 
+        const validator = new Ajv({ strict: false });
+        addFormats(validator);
+
+        validator.validateSchema(schema);
+        expect(validator.errors).toBeNull();
+        validator.compile(schema); // Will find MissingRef errors
+
         if (process.env.UPDATE_SCHEMA) {
             writeFileSync(schemaFile, stringify(schema, { space: 2 }) + "\n", "utf8");
         }
diff --git a/test/vega-lite/schema.json b/test/vega-lite/schema.json
index 3d7d2cac6..60a968ace 100644
--- a/test/vega-lite/schema.json
+++ b/test/vega-lite/schema.json
@@ -867,22 +867,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -1558,18 +1554,14 @@
           "description": "The anchor position of the axis in pixels. For x-axes with top or bottom orientation, this sets the axis group x coordinate. For y-axes with left or right orientation, this sets the axis group y coordinate.\n\n__Default value__: `0`"
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A string or array of strings indicating the name of custom styles to apply to the axis. A style is a named collection of axis property defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ (none) __Note:__ Any specified style will augment the default style. For example, an x-axis mark with `\"style\": \"foo\"` will use `config.axisX` and `config.style.foo` (the specified style `\"foo\"` has higher precedence)."
+          "description": "A string or array of strings indicating the name of custom styles to apply to the axis. A style is a named collection of axis property defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ (none) __Note:__ Any specified style will augment the default style. For example, an x-axis mark with `\"style\": \"foo\"` will use `config.axisX` and `config.style.foo` (the specified style `\"foo\"` has higher precedence).",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         },
         "tickBand": {
           "anyOf": [
@@ -2515,18 +2507,14 @@
           "description": "The anchor position of the axis in pixels. For x-axes with top or bottom orientation, this sets the axis group x coordinate. For y-axes with left or right orientation, this sets the axis group y coordinate.\n\n__Default value__: `0`"
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A string or array of strings indicating the name of custom styles to apply to the axis. A style is a named collection of axis property defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ (none) __Note:__ Any specified style will augment the default style. For example, an x-axis mark with `\"style\": \"foo\"` will use `config.axisX` and `config.style.foo` (the specified style `\"foo\"` has higher precedence)."
+          "description": "A string or array of strings indicating the name of custom styles to apply to the axis. A style is a named collection of axis property defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ (none) __Note:__ Any specified style will augment the default style. For example, an x-axis mark with `\"style\": \"foo\"` will use `config.axisX` and `config.style.foo` (the specified style `\"foo\"` has higher precedence).",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         },
         "tickBand": {
           "anyOf": [
@@ -3686,22 +3674,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -4947,10 +4931,10 @@
               "items": {
                 "$ref": "#/definitions/StringFieldDef<Field>"
               },
-              "type": "array"
-            },
-            {
-              "type": "null"
+              "type": [
+                "array",
+                "null"
+              ]
             }
           ],
           "description": "The tooltip text to show upon mouse hover. Specifying `tooltip` encoding overrides [the `tooltip` property in the mark definition](https://vega.github.io/vega-lite/docs/mark.html#mark-def).\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip in Vega-Lite."
@@ -5534,18 +5518,14 @@
               ]
             },
             "value": {
-              "anyOf": [
-                {
-                  "items": {
-                    "type": "number"
-                  },
-                  "type": "array"
-                },
-                {
-                  "type": "null"
-                }
-              ],
-              "description": "A constant value in visual domain (e.g., `\"red\"` / `\"#0099ff\"` / [gradient definition](https://vega.github.io/vega-lite/docs/types.html#gradient) for color, values between `0` to `1` for opacity)."
+              "description": "A constant value in visual domain (e.g., `\"red\"` / `\"#0099ff\"` / [gradient definition](https://vega.github.io/vega-lite/docs/types.html#gradient) for color, values between `0` to `1` for opacity).",
+              "items": {
+                "type": "number"
+              },
+              "type": [
+                "array",
+                "null"
+              ]
             }
           },
           "required": [
@@ -5726,13 +5706,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -5893,13 +5873,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -6058,7 +6038,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -6066,9 +6049,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -6149,10 +6129,10 @@
               "$ref": "#/definitions/Gradient"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -6300,10 +6280,10 @@
         "value": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -6585,18 +6565,14 @@
               "description": "Predicate for triggering the condition"
             },
             "value": {
-              "anyOf": [
-                {
-                  "items": {
-                    "type": "number"
-                  },
-                  "type": "array"
-                },
-                {
-                  "type": "null"
-                }
-              ],
-              "description": "A constant value in visual domain (e.g., `\"red\"` / `\"#0099ff\"` / [gradient definition](https://vega.github.io/vega-lite/docs/types.html#gradient) for color, values between `0` to `1` for opacity)."
+              "description": "A constant value in visual domain (e.g., `\"red\"` / `\"#0099ff\"` / [gradient definition](https://vega.github.io/vega-lite/docs/types.html#gradient) for color, values between `0` to `1` for opacity).",
+              "items": {
+                "type": "number"
+              },
+              "type": [
+                "array",
+                "null"
+              ]
             }
           },
           "required": [
@@ -6729,13 +6705,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -6888,13 +6864,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -7045,7 +7021,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -7053,9 +7032,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -7128,10 +7104,10 @@
               "$ref": "#/definitions/Gradient"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -7259,10 +7235,10 @@
         "value": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -8612,13 +8588,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -8734,13 +8710,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -8984,10 +8960,10 @@
               "items": {
                 "$ref": "#/definitions/StringFieldDef<Field>"
               },
-              "type": "array"
-            },
-            {
-              "type": "null"
+              "type": [
+                "array",
+                "null"
+              ]
             }
           ],
           "description": "The tooltip text to show upon mouse hover. Specifying `tooltip` encoding overrides [the `tooltip` property in the mark definition](https://vega.github.io/vega-lite/docs/mark.html#mark-def).\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip in Vega-Lite."
@@ -9238,13 +9214,11 @@
         "equal": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "string",
+                "number",
+                "boolean"
+              ]
             },
             {
               "$ref": "#/definitions/DateTime"
@@ -9287,10 +9261,10 @@
         "gte": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "number"
+              "type": [
+                "string",
+                "number"
+              ]
             },
             {
               "$ref": "#/definitions/DateTime"
@@ -9329,10 +9303,10 @@
         "gt": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "number"
+              "type": [
+                "string",
+                "number"
+              ]
             },
             {
               "$ref": "#/definitions/DateTime"
@@ -9371,10 +9345,10 @@
         "lte": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "number"
+              "type": [
+                "string",
+                "number"
+              ]
             },
             {
               "$ref": "#/definitions/DateTime"
@@ -9413,10 +9387,10 @@
         "lt": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "number"
+              "type": [
+                "string",
+                "number"
+              ]
             },
             {
               "$ref": "#/definitions/DateTime"
@@ -9711,13 +9685,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -9812,13 +9786,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -9913,13 +9887,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -10014,13 +9988,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
-            },
-            {
-              "$ref": "#/definitions/BinParams"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
-              "type": "null"
+              "$ref": "#/definitions/BinParams"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -10178,7 +10152,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -10186,9 +10163,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -10272,7 +10246,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -10280,9 +10257,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -10362,14 +10336,14 @@
               "items": {
                 "anyOf": [
                   {
-                    "type": "number"
+                    "type": [
+                      "number",
+                      "null"
+                    ]
                   },
                   {
                     "$ref": "#/definitions/DateTime"
                   },
-                  {
-                    "type": "null"
-                  },
                   {
                     "$ref": "#/definitions/ExprRef"
                   }
@@ -11845,7 +11819,11 @@
           "items": {
             "type": "number"
           },
-          "type": "array"
+          "type": [
+            "array",
+            "string",
+            "object"
+          ]
         },
         {
           "items": {
@@ -11864,12 +11842,6 @@
             "type": "object"
           },
           "type": "array"
-        },
-        {
-          "type": "string"
-        },
-        {
-          "type": "object"
         }
       ]
     },
@@ -11929,10 +11901,10 @@
               "$ref": "#/definitions/Stream"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "string",
+                "boolean"
+              ]
             }
           ],
           "description": "Clears the selection, emptying it of all values. This property can be a [Event Stream](https://vega.github.io/vega/docs/event-streams/) or `false` to disable clear.\n\n__Default value:__ `dblclick`.\n\n__See also:__ [`clear` examples ](https://vega.github.io/vega-lite/docs/selection.html#clear) in the documentation."
@@ -12004,10 +11976,10 @@
               "$ref": "#/definitions/Stream"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "string",
+                "boolean"
+              ]
             }
           ],
           "description": "Clears the selection, emptying it of all values. This property can be a [Event Stream](https://vega.github.io/vega/docs/event-streams/) or `false` to disable clear.\n\n__Default value:__ `dblclick`.\n\n__See also:__ [`clear` examples ](https://vega.github.io/vega-lite/docs/selection.html#clear) in the documentation."
@@ -14870,22 +14842,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -15968,22 +15936,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -16782,18 +16746,14 @@
           ]
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A string or array of strings indicating the name of custom styles to apply to the mark. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles. Any [mark properties](https://vega.github.io/vega-lite/docs/encoding.html#mark-prop) explicitly defined within the `encoding` will override a style default.\n\n__Default value:__ The mark's name. For example, a bar mark will have style `\"bar\"` by default. __Note:__ Any specified style will augment the default style. For example, a bar mark with `\"style\": \"foo\"` will receive from `config.style.bar` and `config.style.foo` (the specified style `\"foo\"` has higher precedence)."
+          "description": "A string or array of strings indicating the name of custom styles to apply to the mark. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles. Any [mark properties](https://vega.github.io/vega-lite/docs/encoding.html#mark-prop) explicitly defined within the `encoding` will override a style default.\n\n__Default value:__ The mark's name. For example, a bar mark will have style `\"bar\"` by default. __Note:__ Any specified style will augment the default style. For example, a bar mark with `\"style\": \"foo\"` will receive from `config.style.bar` and `config.style.foo` (the specified style `\"foo\"` has higher precedence).",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         },
         "tension": {
           "anyOf": [
@@ -16879,22 +16839,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -17354,7 +17310,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -17362,9 +17321,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -18120,18 +18076,14 @@
           ]
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A string or array of strings indicating the name of custom styles to apply to the mark. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles. Any [mark properties](https://vega.github.io/vega-lite/docs/encoding.html#mark-prop) explicitly defined within the `encoding` will override a style default.\n\n__Default value:__ The mark's name. For example, a bar mark will have style `\"bar\"` by default. __Note:__ Any specified style will augment the default style. For example, a bar mark with `\"style\": \"foo\"` will receive from `config.style.bar` and `config.style.foo` (the specified style `\"foo\"` has higher precedence)."
+          "description": "A string or array of strings indicating the name of custom styles to apply to the mark. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles. Any [mark properties](https://vega.github.io/vega-lite/docs/encoding.html#mark-prop) explicitly defined within the `encoding` will override a style default.\n\n__Default value:__ The mark's name. For example, a bar mark will have style `\"bar\"` by default. __Note:__ Any specified style will augment the default style. For example, a bar mark with `\"style\": \"foo\"` will receive from `config.style.bar` and `config.style.foo` (the specified style `\"foo\"` has higher precedence).",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         },
         "tension": {
           "anyOf": [
@@ -18212,22 +18164,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -18362,30 +18310,26 @@
       "type": "object"
     },
     "Padding": {
-      "anyOf": [
-        {
+      "additionalProperties": false,
+      "minimum": 0,
+      "properties": {
+        "bottom": {
           "type": "number"
         },
-        {
-          "additionalProperties": false,
-          "properties": {
-            "bottom": {
-              "type": "number"
-            },
-            "left": {
-              "type": "number"
-            },
-            "right": {
-              "type": "number"
-            },
-            "top": {
-              "type": "number"
-            }
-          },
-          "type": "object"
+        "left": {
+          "type": "number"
+        },
+        "right": {
+          "type": "number"
+        },
+        "top": {
+          "type": "number"
         }
-      ],
-      "minimum": 0
+      },
+      "type": [
+        "number",
+        "object"
+      ]
     },
     "ParameterExtent": {
       "anyOf": [
@@ -18454,10 +18398,10 @@
     "ParseValue": {
       "anyOf": [
         {
-          "type": "null"
-        },
-        {
-          "type": "string"
+          "type": [
+            "null",
+            "string"
+          ]
         },
         {
           "const": "string",
@@ -18519,10 +18463,10 @@
               "$ref": "#/definitions/Stream"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "string",
+                "boolean"
+              ]
             }
           ],
           "description": "Clears the selection, emptying it of all values. This property can be a [Event Stream](https://vega.github.io/vega/docs/event-streams/) or `false` to disable clear.\n\n__Default value:__ `dblclick`.\n\n__See also:__ [`clear` examples ](https://vega.github.io/vega-lite/docs/selection.html#clear) in the documentation."
@@ -18587,10 +18531,10 @@
               "$ref": "#/definitions/Stream"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "string",
+                "boolean"
+              ]
             }
           ],
           "description": "Clears the selection, emptying it of all values. This property can be a [Event Stream](https://vega.github.io/vega/docs/event-streams/) or `false` to disable clear.\n\n__Default value:__ `dblclick`.\n\n__See also:__ [`clear` examples ](https://vega.github.io/vega-lite/docs/selection.html#clear) in the documentation."
@@ -18729,10 +18673,10 @@
               "$ref": "#/definitions/StackOffset"
             },
             {
-              "type": "null"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "null",
+                "boolean"
+              ]
             }
           ],
           "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -18787,10 +18731,10 @@
               "$ref": "#/definitions/StackOffset"
             },
             {
-              "type": "null"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "null",
+                "boolean"
+              ]
             }
           ],
           "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -18842,7 +18786,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -18850,9 +18797,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -18893,10 +18837,10 @@
               "$ref": "#/definitions/StackOffset"
             },
             {
-              "type": "null"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "null",
+                "boolean"
+              ]
             }
           ],
           "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -18946,7 +18890,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -18954,9 +18901,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -18986,10 +18930,10 @@
               "$ref": "#/definitions/StackOffset"
             },
             {
-              "type": "null"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "null",
+                "boolean"
+              ]
             }
           ],
           "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -19566,16 +19510,12 @@
       "items": {
         "anyOf": [
           {
-            "type": "null"
-          },
-          {
-            "type": "boolean"
-          },
-          {
-            "type": "string"
-          },
-          {
-            "type": "number"
+            "type": [
+              "null",
+              "boolean",
+              "string",
+              "number"
+            ]
           },
           {
             "$ref": "#/definitions/RangeRawArray"
@@ -19612,14 +19552,14 @@
             },
             "scheme": {
               "anyOf": [
-                {
-                  "type": "string"
-                },
                 {
                   "items": {
                     "type": "string"
                   },
-                  "type": "array"
+                  "type": [
+                    "string",
+                    "array"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ColorScheme"
@@ -20350,22 +20290,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -20659,13 +20595,13 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -20809,16 +20745,12 @@
               "items": {
                 "anyOf": [
                   {
-                    "type": "null"
-                  },
-                  {
-                    "type": "string"
-                  },
-                  {
-                    "type": "number"
-                  },
-                  {
-                    "type": "boolean"
+                    "type": [
+                      "null",
+                      "string",
+                      "number",
+                      "boolean"
+                    ]
                   },
                   {
                     "$ref": "#/definitions/DateTime"
@@ -20913,10 +20845,10 @@
         "nice": {
           "anyOf": [
             {
-              "type": "boolean"
-            },
-            {
-              "type": "number"
+              "type": [
+                "boolean",
+                "number"
+              ]
             },
             {
               "$ref": "#/definitions/TimeInterval"
@@ -20974,29 +20906,24 @@
               "$ref": "#/definitions/RangeEnum"
             },
             {
+              "additionalProperties": false,
               "items": {
                 "anyOf": [
-                  {
-                    "type": "number"
-                  },
-                  {
-                    "type": "string"
-                  },
                   {
                     "items": {
                       "type": "number"
                     },
-                    "type": "array"
+                    "type": [
+                      "number",
+                      "string",
+                      "array"
+                    ]
                   },
                   {
                     "$ref": "#/definitions/ExprRef"
                   }
                 ]
               },
-              "type": "array"
-            },
-            {
-              "additionalProperties": false,
               "properties": {
                 "field": {
                   "type": "string"
@@ -21005,7 +20932,10 @@
               "required": [
                 "field"
               ],
-              "type": "object"
+              "type": [
+                "array",
+                "object"
+              ]
             }
           ],
           "description": "The range of the scale. One of:\n\n- A string indicating a [pre-defined named scale range](https://vega.github.io/vega-lite/docs/scale.html#range-config) (e.g., example, `\"symbol\"`, or `\"diverging\"`).\n\n- For [continuous scales](https://vega.github.io/vega-lite/docs/scale.html#continuous), two-element array indicating  minimum and maximum values, or an array with more than two entries for specifying a [piecewise scale](https://vega.github.io/vega-lite/docs/scale.html#piecewise).\n\n- For [discrete](https://vega.github.io/vega-lite/docs/scale.html#discrete) and [discretizing](https://vega.github.io/vega-lite/docs/scale.html#discretizing) scales, an array of desired output values or an object with a `field` property representing the range values.  For example, if a field `color` contains CSS color names, we can set `range` to `{field: \"color\"}`.\n\n__Notes:__\n\n1) For color scales you can also specify a color [`scheme`](https://vega.github.io/vega-lite/docs/scale.html#scheme) instead of `range`.\n\n2) Any directly specified `range` for `x` and `y` channels will be ignored. Range can be customized via the view's corresponding [size](https://vega.github.io/vega-lite/docs/size.html) (`width` and `height`)."
@@ -21013,10 +20943,10 @@
         "rangeMax": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
+              "type": [
+                "number",
+                "string"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -21027,10 +20957,10 @@
         "rangeMin": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
+              "type": [
+                "number",
+                "string"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -21902,13 +21832,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22061,13 +21991,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22196,10 +22126,10 @@
                   "$ref": "#/definitions/Gradient"
                 },
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -22226,7 +22156,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -22234,9 +22167,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22325,10 +22255,10 @@
             "value": {
               "anyOf": [
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -22369,13 +22299,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22504,10 +22434,10 @@
                   "$ref": "#/definitions/Gradient"
                 },
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -22534,13 +22464,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22693,7 +22623,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -22701,9 +22634,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -22792,10 +22722,10 @@
             "value": {
               "anyOf": [
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -22822,7 +22752,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -22830,9 +22763,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -23212,13 +23142,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -23388,7 +23318,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -23396,9 +23329,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -23445,10 +23375,10 @@
                   "$ref": "#/definitions/StackOffset"
                 },
                 {
-                  "type": "null"
-                },
-                {
-                  "type": "boolean"
+                  "type": [
+                    "null",
+                    "boolean"
+                  ]
                 }
               ],
               "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -23612,13 +23542,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -23744,10 +23674,10 @@
             "value": {
               "anyOf": [
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23774,13 +23704,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -23933,13 +23863,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24068,10 +23998,10 @@
                   "$ref": "#/definitions/Gradient"
                 },
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -24098,13 +24028,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24260,13 +24190,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24419,13 +24349,13 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24578,7 +24508,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -24586,9 +24519,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24730,7 +24660,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -24738,9 +24671,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -24787,10 +24717,10 @@
                   "$ref": "#/definitions/StackOffset"
                 },
                 {
-                  "type": "null"
-                },
-                {
-                  "type": "boolean"
+                  "type": [
+                    "null",
+                    "boolean"
+                  ]
                 }
               ],
               "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -24950,10 +24880,10 @@
               "items": {
                 "$ref": "#/definitions/StringFieldDef<Field>"
               },
-              "type": "array"
-            },
-            {
-              "type": "null"
+              "type": [
+                "array",
+                "null"
+              ]
             }
           ],
           "description": "The tooltip text to show upon mouse hover. Specifying `tooltip` encoding overrides [the `tooltip` property in the mark definition](https://vega.github.io/vega-lite/docs/mark.html#mark-def).\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip in Vega-Lite."
@@ -24974,7 +24904,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -24982,9 +24915,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -25073,10 +25003,10 @@
             "value": {
               "anyOf": [
                 {
-                  "type": "string"
-                },
-                {
-                  "type": "null"
+                  "type": [
+                    "string",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25114,7 +25044,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -25122,9 +25055,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -25182,10 +25112,10 @@
                   "$ref": "#/definitions/StackOffset"
                 },
                 {
-                  "type": "null"
-                },
-                {
-                  "type": "boolean"
+                  "type": [
+                    "null",
+                    "boolean"
+                  ]
                 }
               ],
               "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -25460,7 +25390,10 @@
             "bin": {
               "anyOf": [
                 {
-                  "type": "boolean"
+                  "type": [
+                    "boolean",
+                    "null"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/BinParams"
@@ -25468,9 +25401,6 @@
                 {
                   "const": "binned",
                   "type": "string"
-                },
-                {
-                  "type": "null"
                 }
               ],
               "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -25528,10 +25458,10 @@
                   "$ref": "#/definitions/StackOffset"
                 },
                 {
-                  "type": "null"
-                },
-                {
-                  "type": "boolean"
+                  "type": [
+                    "null",
+                    "boolean"
+                  ]
                 }
               ],
               "description": "Type of stacking offset if the field should be stacked. `stack` is only applicable for `x`, `y`, `theta`, and `radius` channels with continuous domains. For example, `stack` of `y` can be used to customize stacking for a vertical bar chart.\n\n`stack` can be one of the following values:\n- `\"zero\"` or `true`: stacking with baseline offset at zero value of the scale (for creating typical stacked [bar](https://vega.github.io/vega-lite/docs/stack.html#bar) and [area](https://vega.github.io/vega-lite/docs/stack.html#area) chart).\n- `\"normalize\"` - stacking with normalized domain (for creating [normalized stacked bar and area charts](https://vega.github.io/vega-lite/docs/stack.html#normalized). <br/>\n-`\"center\"` - stacking with center baseline (for [streamgraph](https://vega.github.io/vega-lite/docs/stack.html#streamgraph)).\n- `null` or `false` - No-stacking. This will produce layered [bar](https://vega.github.io/vega-lite/docs/stack.html#layered-bar-chart) and area chart.\n\n__Default value:__ `zero` for plots with all of the following conditions are true: (1) the mark is `bar`, `area`, or `arc`; (2) the stacked measure channel (x or y) has a linear scale; (3) At least one of non-position channels mapped to an unaggregated field that is different from x and y. Otherwise, `null` by default.\n\n__See also:__ [`stack`](https://vega.github.io/vega-lite/docs/stack.html) documentation."
@@ -26101,7 +26031,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -26109,9 +26042,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -26281,16 +26211,12 @@
       "type": "string"
     },
     "Text": {
-      "anyOf": [
-        {
-          "type": "string"
-        },
-        {
-          "items": {
-            "type": "string"
-          },
-          "type": "array"
-        }
+      "items": {
+        "type": "string"
+      },
+      "type": [
+        "string",
+        "array"
       ]
     },
     "TextBaseline": {
@@ -27036,22 +26962,18 @@
         "tooltip": {
           "anyOf": [
             {
-              "type": "number"
-            },
-            {
-              "type": "string"
-            },
-            {
-              "type": "boolean"
+              "type": [
+                "number",
+                "string",
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/TooltipContent"
             },
             {
               "$ref": "#/definitions/ExprRef"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "The tooltip text string to show upon mouse hover or an object defining which fields should the tooltip be derived from.\n\n- If `tooltip` is `true` or `{\"content\": \"encoding\"}`, then all fields from `encoding` will be used.\n- If `tooltip` is `{\"content\": \"data\"}`, then all fields that appear in the highlighted data point will be used.\n- If set to `null` or `false`, then no tooltip will be used.\n\nSee the [`tooltip`](https://vega.github.io/vega-lite/docs/tooltip.html) documentation for a detailed discussion about tooltip  in Vega-Lite.\n\n__Default value:__ `null`"
@@ -27463,18 +27385,14 @@
           ]
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A [mark style property](https://vega.github.io/vega-lite/docs/config.html#style) to apply to the title text mark.\n\n__Default value:__ `\"group-title\"`."
+          "description": "A [mark style property](https://vega.github.io/vega-lite/docs/config.html#style) to apply to the title text mark.\n\n__Default value:__ `\"group-title\"`.",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         },
         "subtitle": {
           "$ref": "#/definitions/Text",
@@ -28815,16 +28733,12 @@
         "views": {
           "description": "By default, top-level selections are applied to every view in the visualization. If this property is specified, selections will only be applied to views with the given names.",
           "items": {
-            "anyOf": [
-              {
-                "type": "string"
-              },
-              {
-                "items": {
-                  "type": "string"
-                },
-                "type": "array"
-              }
+            "items": {
+              "type": "string"
+            },
+            "type": [
+              "string",
+              "array"
             ]
           },
           "type": "array"
@@ -29188,7 +29102,10 @@
         "bin": {
           "anyOf": [
             {
-              "type": "boolean"
+              "type": [
+                "boolean",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/BinParams"
@@ -29196,9 +29113,6 @@
             {
               "const": "binned",
               "type": "string"
-            },
-            {
-              "type": "null"
             }
           ],
           "description": "A flag for binning a `quantitative` field, [an object defining binning parameters](https://vega.github.io/vega-lite/docs/bin.html#params), or indicating that the data for `x` or `y` channel are binned before they are imported into Vega-Lite (`\"binned\"`).\n\n- If `true`, default [binning parameters](https://vega.github.io/vega-lite/docs/bin.html) will be applied.\n\n- If `\"binned\"`, this indicates that the data for the `x` (or `y`) channel are already binned. You can map the bin-start field to `x` (or `y`) and the bin-end field to `x2` (or `y2`). The scale and axis will be formatted similar to binning in Vega-Lite.  To adjust the axis ticks based on the bin step, you can also set the axis's [`tickMinStep`](https://vega.github.io/vega-lite/docs/axis.html#ticks) property.\n\n__Default value:__ `false`\n\n__See also:__ [`bin`](https://vega.github.io/vega-lite/docs/bin.html) documentation."
@@ -29491,10 +29405,10 @@
               "$ref": "#/definitions/Gradient"
             },
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -29529,10 +29443,10 @@
         "value": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -29640,10 +29554,10 @@
         "value": {
           "anyOf": [
             {
-              "type": "string"
-            },
-            {
-              "type": "null"
+              "type": [
+                "string",
+                "null"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"
@@ -29917,18 +29831,14 @@
           ]
         },
         "style": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            }
-          ],
-          "description": "A string or array of strings indicating the name of custom styles to apply to the view background. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ `\"cell\"` __Note:__ Any specified view background properties will augment the default style."
+          "description": "A string or array of strings indicating the name of custom styles to apply to the view background. A style is a named collection of mark property defaults defined within the [style configuration](https://vega.github.io/vega-lite/docs/mark.html#style-config). If style is an array, later styles will override earlier styles.\n\n__Default value:__ `\"cell\"` __Note:__ Any specified view background properties will augment the default style.",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "string",
+            "array"
+          ]
         }
       },
       "type": "object"
@@ -29964,44 +29874,36 @@
           "description": "The mouse cursor used over the view. Any valid [CSS cursor type](https://developer.mozilla.org/en-US/docs/Web/CSS/cursor#Values) can be used."
         },
         "discreteHeight": {
-          "anyOf": [
-            {
+          "additionalProperties": false,
+          "description": "The default height when the plot has non arc marks and either a discrete y-field or no y-field. The height can be either a number indicating a fixed height or an object in the form of `{step: number}` defining the height per discrete step.\n\n__Default value:__ a step size based on `config.view.step`.",
+          "properties": {
+            "step": {
               "type": "number"
-            },
-            {
-              "additionalProperties": false,
-              "properties": {
-                "step": {
-                  "type": "number"
-                }
-              },
-              "required": [
-                "step"
-              ],
-              "type": "object"
             }
+          },
+          "required": [
+            "step"
           ],
-          "description": "The default height when the plot has non arc marks and either a discrete y-field or no y-field. The height can be either a number indicating a fixed height or an object in the form of `{step: number}` defining the height per discrete step.\n\n__Default value:__ a step size based on `config.view.step`."
+          "type": [
+            "number",
+            "object"
+          ]
         },
         "discreteWidth": {
-          "anyOf": [
-            {
+          "additionalProperties": false,
+          "description": "The default width when the plot has non-arc marks and either a discrete x-field or no x-field. The width can be either a number indicating a fixed width or an object in the form of `{step: number}` defining the width per discrete step.\n\n__Default value:__ a step size based on `config.view.step`.",
+          "properties": {
+            "step": {
               "type": "number"
-            },
-            {
-              "additionalProperties": false,
-              "properties": {
-                "step": {
-                  "type": "number"
-                }
-              },
-              "required": [
-                "step"
-              ],
-              "type": "object"
             }
+          },
+          "required": [
+            "step"
           ],
-          "description": "The default width when the plot has non-arc marks and either a discrete x-field or no x-field. The width can be either a number indicating a fixed width or an object in the form of `{step: number}` defining the width per discrete step.\n\n__Default value:__ a step size based on `config.view.step`."
+          "type": [
+            "number",
+            "object"
+          ]
         },
         "fill": {
           "anyOf": [

From 291ebf909b2481d1f2be94142497e5afb108c105 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Sat, 27 Mar 2021 16:33:15 -0400
Subject: [PATCH 4/7] Simplifying logic in addReachable, adding tests

---
 src/Utils/removeUnreachable.ts      | 69 ++++++++++++-----------------
 test/unit/removeUnreachable.test.ts | 60 +++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 41 deletions(-)
 create mode 100644 test/unit/removeUnreachable.test.ts

diff --git a/src/Utils/removeUnreachable.ts b/src/Utils/removeUnreachable.ts
index 8619e5638..cfbd3efaa 100644
--- a/src/Utils/removeUnreachable.ts
+++ b/src/Utils/removeUnreachable.ts
@@ -1,14 +1,24 @@
 import { JSONSchema7Definition } from "json-schema";
-import { isArray, isBoolean } from "util";
 import { Definition } from "./../Schema/Definition";
 import { StringMap } from "./StringMap";
 
 function addReachable(
-    definition: Definition | JSONSchema7Definition,
+    definition: Definition | JSONSchema7Definition | undefined | Array<Definition | JSONSchema7Definition>,
     definitions: StringMap<Definition>,
     reachable: Set<string>
 ) {
-    if (isBoolean(definition)) {
+    function addReachableProperties(properties: Record<any, Definition | JSONSchema7Definition> | undefined) {
+        for (const def of Object.values(properties || {})) {
+            addReachable(def, definitions, reachable);
+        }
+    }
+    if (!definition || typeof definition !== "object") {
+        return;
+    }
+    if (Array.isArray(definition)) {
+        for (const def of definition) {
+            addReachable(def, definitions, reachable);
+        }
         return;
     }
 
@@ -21,45 +31,22 @@ function addReachable(
         reachable.add(typeName);
         addReachable(definitions[typeName], definitions, reachable);
     } else {
-        if (definition.anyOf) {
-            for (const def of definition.anyOf) {
-                addReachable(def, definitions, reachable);
-            }
-        }
-        if (definition.allOf) {
-            for (const def of definition.allOf) {
-                addReachable(def, definitions, reachable);
-            }
-        }
-        if (definition.oneOf) {
-            for (const def of definition.oneOf) {
-                addReachable(def, definitions, reachable);
-            }
-        }
-        if (definition.not) {
-            addReachable(definition.not, definitions, reachable);
-        }
-        if (definition.type === "object" || (Array.isArray(definition.type) && definition.type.includes("object"))) {
-            for (const prop in definition.properties || {}) {
-                const propDefinition = definition.properties![prop];
-                addReachable(propDefinition, definitions, reachable);
-            }
+        addReachable(definition.anyOf, definitions, reachable);
+        addReachable(definition.allOf, definitions, reachable);
+        addReachable(definition.oneOf, definitions, reachable);
+        addReachable(definition.not, definitions, reachable);
+        addReachable(definition.contains, definitions, reachable);
 
-            const additionalProperties = definition.additionalProperties;
-            if (additionalProperties) {
-                addReachable(additionalProperties, definitions, reachable);
-            }
-        }
-        if (definition.type === "array" || (Array.isArray(definition.type) && definition.type.includes("array"))) {
-            const items = definition.items;
-            if (isArray(items)) {
-                for (const item of items) {
-                    addReachable(item, definitions, reachable);
-                }
-            } else if (items) {
-                addReachable(items, definitions, reachable);
-            }
-        }
+        addReachable(definition.if, definitions, reachable);
+        addReachable(definition.then, definitions, reachable);
+        addReachable(definition.else, definitions, reachable);
+
+        addReachableProperties(definition.properties);
+        addReachableProperties(definition.patternProperties);
+        addReachable(definition.additionalProperties, definitions, reachable);
+
+        addReachable(definition.items, definitions, reachable);
+        addReachable(definition.additionalItems, definitions, reachable);
     }
 }
 
diff --git a/test/unit/removeUnreachable.test.ts b/test/unit/removeUnreachable.test.ts
new file mode 100644
index 000000000..80d1feef2
--- /dev/null
+++ b/test/unit/removeUnreachable.test.ts
@@ -0,0 +1,60 @@
+import { Definition } from "../../src/Schema/Definition";
+import { removeUnreachable } from "../../src/Utils/removeUnreachable";
+import { StringMap } from "../../src/Utils/StringMap";
+
+type DefinitionGenerator = (makeRef: (reffedDefinition?: Definition) => Definition) => Definition;
+function packDefinition(defGen: DefinitionGenerator): [root: Definition, definitions: StringMap<Definition>] {
+    const definitions: StringMap<Definition> = {};
+    let refIdx = 0;
+    function makeRefFunc(reffedDefinition: Definition = {}): Definition {
+        const defName = `packedDef${refIdx++}`;
+        definitions[defName] = reffedDefinition;
+        return { $ref: `#/definitions/${defName}` };
+    }
+    const root = defGen(makeRefFunc);
+    return [root, definitions];
+}
+
+function assertReachableDefinitions(defGen: DefinitionGenerator) {
+    return (): void => {
+        const [rootTypeDefinition, definitions] = packDefinition(defGen);
+        let prunedDefinitions = removeUnreachable(rootTypeDefinition, definitions);
+        expect(prunedDefinitions).toEqual(definitions);
+
+        definitions["extraDef"] = {};
+        prunedDefinitions = removeUnreachable(rootTypeDefinition, definitions);
+        expect(prunedDefinitions).not.toEqual(definitions);
+    };
+}
+
+describe("removeUnreachable", () => {
+    it(
+        "preserves reachability for a packed definition",
+        assertReachableDefinitions((makeRef) => ({
+            type: ["array", "boolean", "integer", "null", "number", "object", "string"],
+            allOf: [makeRef(), makeRef()],
+            anyOf: [makeRef(), makeRef()],
+            oneOf: [makeRef(), makeRef()],
+            contains: makeRef(),
+            not: makeRef(),
+            if: makeRef(),
+            then: makeRef(),
+            else: makeRef(),
+            properties: { foo: makeRef(), bar: makeRef(), $ref: makeRef() },
+            patternProperties: { "^foo$": makeRef(), "b.a.r": makeRef(), $ref: makeRef() },
+            additionalProperties: makeRef(),
+            items: [makeRef(), makeRef()],
+            additionalItems: makeRef(),
+        }))
+    );
+
+    it(
+        "preserves reachability for homogenous arrays",
+        assertReachableDefinitions((makeRef) => ({ type: "array", items: makeRef() }))
+    );
+
+    it(
+        "preserves reachability for indirect refs",
+        assertReachableDefinitions((makeRef) => ({ not: makeRef({ not: makeRef() }) }))
+    );
+});

From 30c22f70e7e2ef5cee6276a9f6db30cac8c1e2e7 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Sat, 27 Mar 2021 17:29:26 -0400
Subject: [PATCH 5/7] Adding functional tests, mergeDefinitions tests

In addition to the raw schema tests which just check that nothing has
changed since the last snapshot, this adds makeExemplar, which builds
a raw value using the parsed BaseType representation of a TypeScript
type tree. This way, tests can specify valid/invalid data to be verified
using the Ajv validator in addition to raw schema output tests.
---
 src/Utils/makeExemplar.ts                    | 230 +++++++++++++++++++
 test/utils.ts                                | 120 +++++++++-
 test/valid-data-type.test.ts                 |   9 +-
 test/valid-data/type-union-weird/main.ts     |  72 ++++++
 test/valid-data/type-union-weird/schema.json | 112 +++++++++
 test/vega-lite.test.ts                       |   4 +-
 6 files changed, 537 insertions(+), 10 deletions(-)
 create mode 100644 src/Utils/makeExemplar.ts
 create mode 100644 test/valid-data/type-union-weird/main.ts
 create mode 100644 test/valid-data/type-union-weird/schema.json

diff --git a/src/Utils/makeExemplar.ts b/src/Utils/makeExemplar.ts
new file mode 100644
index 000000000..0789b1425
--- /dev/null
+++ b/src/Utils/makeExemplar.ts
@@ -0,0 +1,230 @@
+import { AliasType } from "../Type/AliasType";
+import { AnnotatedType } from "../Type/AnnotatedType";
+import { ArrayType } from "../Type/ArrayType";
+import { BaseType } from "../Type/BaseType";
+import { BooleanType } from "../Type/BooleanType";
+import { DefinitionType } from "../Type/DefinitionType";
+import { EnumType } from "../Type/EnumType";
+import { IntersectionType } from "../Type/IntersectionType";
+import { LiteralType } from "../Type/LiteralType";
+import { NullType } from "../Type/NullType";
+import { NumberType } from "../Type/NumberType";
+import { ObjectType } from "../Type/ObjectType";
+import { OptionalType } from "../Type/OptionalType";
+import { ReferenceType } from "../Type/ReferenceType";
+import { RestType } from "../Type/RestType";
+import { StringType } from "../Type/StringType";
+import { SymbolType } from "../Type/SymbolType";
+import { TupleType } from "../Type/TupleType";
+import { UndefinedType } from "../Type/UndefinedType";
+import { UnionType } from "../Type/UnionType";
+
+export function makeExemplar(type: BaseType | undefined): unknown {
+    return makeExemplars(type)[0];
+}
+
+export function makeExemplars(type: BaseType | undefined): readonly unknown[] {
+    while (type) {
+        if (
+            type instanceof AliasType ||
+            type instanceof AnnotatedType ||
+            type instanceof DefinitionType ||
+            type instanceof ReferenceType
+        ) {
+            type = type.getType();
+        } else if (type instanceof ArrayType) {
+            const itemExemplars = makeExemplars(type.getItem());
+            return [[], itemExemplars].concat(itemExemplars.map((e) => [e, e]));
+        } else if (type instanceof BooleanType) {
+            return [true, false];
+        } else if (type instanceof EnumType) {
+            return type.getValues();
+        } else if (type instanceof IntersectionType) {
+            return makeIntersectionExemplars(type);
+        } else if (type instanceof LiteralType) {
+            return [type.getValue()];
+        } else if (type instanceof NullType) {
+            return [null];
+        } else if (type instanceof NumberType) {
+            return [0, 1, -1];
+        } else if (type instanceof ObjectType) {
+            return makeObjectExemplars(type);
+        } else if (type instanceof OptionalType) {
+            return makeExemplars(type.getType()).concat([undefined]);
+        } else if (type instanceof RestType) {
+            const exemplar = makeExemplars(type.getType());
+            return [[], [exemplar], [exemplar, exemplar]];
+        } else if (type instanceof StringType) {
+            return ["", "lorem ipsum"];
+        } else if (type instanceof SymbolType) {
+            return [Symbol(), Symbol()];
+        } else if (type instanceof TupleType) {
+            return makeTupleExemplars(type);
+        } else if (type instanceof UndefinedType) {
+            return [undefined];
+        } else if (type instanceof UnionType) {
+            return type
+                .getTypes()
+                .map((t) => makeExemplars(t))
+                .reduce((list, choice) => list.concat(choice), []);
+        } else {
+            throw new Error(`Can't make exemplar from type ${type.constructor.name}: ${type}`);
+        }
+    }
+    return [undefined];
+}
+
+type UnknownObject = Record<string, unknown>;
+
+function makeIntersectionExemplars(type: IntersectionType): unknown[] {
+    const warnings: string[] = [];
+    function intersectExemplars(
+        exemplars: (readonly unknown[])[],
+        currentResult: unknown,
+        members: UnknownObject[]
+    ): unknown[] {
+        for (let i = 0; i < exemplars.length; i++) {
+            const choices = exemplars[i];
+            if (choices.length > 1) {
+                return choices
+                    .map((choice) => {
+                        const subExemplars = exemplars.slice(i); // including the one with the multiple-choice element
+                        subExemplars[0] = [choice]; // ...and overwriting it with a single choice
+                        const subMembers = members.slice();
+                        return intersectExemplars(subExemplars, currentResult, subMembers);
+                    })
+                    .reduce((list, choice) => list.concat(choice), []);
+            } else if (choices.length === 0) {
+                return [];
+            }
+            const exemplar = choices[0];
+            if (exemplar == null) {
+                warnings.push(`Can't make exemplar from intersection with null/undefined`);
+                return [];
+            } else if (exemplar && typeof exemplar === "object" && !Array.isArray(exemplar)) {
+                members.push(exemplar as UnknownObject);
+            } else {
+                // We can only have one non-object member. It will become the base we add all the others to.
+                if (currentResult !== undefined && exemplar !== currentResult) {
+                    warnings.push(`Can't make exemplar from complex intersection`);
+                    return [];
+                } else {
+                    currentResult = exemplar;
+                }
+            }
+        }
+
+        // We've gotten here, which means we have exactly one choice at this level of recursion.
+        // Now we just need to merge the intersection members.
+
+        if (members.length === 0) {
+            // no properties to add, just return the base value
+            return [currentResult];
+        }
+        let result: UnknownObject;
+        if (currentResult === undefined) {
+            result = {};
+        } else if (typeof currentResult !== "object") {
+            // for primitive values, box them to allow adding properties
+            result = new (currentResult as any).constructor(currentResult);
+        } else if (Array.isArray(currentResult)) {
+            result = currentResult.slice() as any;
+        } else {
+            result = Object.assign({}, currentResult);
+        }
+
+        const collisions: Record<string, unknown[]> = {};
+
+        for (const member of members) {
+            for (const [key, value] of Object.entries(member)) {
+                if (Object.getOwnPropertyDescriptor(result, key)) {
+                    if (!(key in collisions)) {
+                        collisions[key] = [result[key]];
+                    }
+                    collisions[key].push(value);
+                } else {
+                    result[key] = value;
+                }
+            }
+        }
+
+        return resolveObjectChoices(result, Object.entries(collisions));
+    }
+
+    const choices = intersectExemplars(
+        type.getTypes().map((t) => makeExemplars(t)),
+        undefined,
+        []
+    );
+    if (choices.length === 0) {
+        throw new Error(`Could not make intersection; warnings=${JSON.stringify(warnings)}`);
+    }
+    return choices;
+}
+
+function resolveObjectChoices(exemplar: UnknownObject, choiceEntries: [string, readonly unknown[]][]): UnknownObject[] {
+    if (choiceEntries.length === 0) {
+        return [exemplar];
+    }
+    const [prop, choices] = choiceEntries[0];
+    const results: UnknownObject[] = [];
+    for (const choice of choices) {
+        const newExemplar = new (exemplar.constructor as new (val: UnknownObject) => UnknownObject)(exemplar);
+        newExemplar[prop] = choice;
+        results.push(...resolveObjectChoices(exemplar, choiceEntries.slice(1)));
+    }
+    return results;
+}
+
+function makeObjectExemplars(type: ObjectType): readonly unknown[] {
+    const fullObject: UnknownObject = {};
+    const emptyObject: UnknownObject = {};
+    const choices: [string, readonly unknown[]][] = [];
+    let hasOptional = false;
+    for (const prop of type.getProperties()) {
+        const name = prop.getName();
+        const values = makeExemplars(prop.getType());
+        if (values.length === 0) {
+            throw new Error(`Cannot make object exemplar with invalid property for type ${type}`);
+        } else if (values.length > 1) {
+            choices.push([name, values]);
+        }
+        const value = values[0];
+        fullObject[name] = value;
+        if (prop.isRequired()) {
+            emptyObject[name] = value;
+        } else {
+            hasOptional = true;
+        }
+    }
+    const additional = type.getAdditionalProperties();
+    if (additional === true) {
+        hasOptional = true;
+        fullObject["<UNLIKELY PROPERTY>"] = "UNLIKELY VALUE";
+    } else if (additional) {
+        hasOptional = true;
+        choices.push(["<UNLIKELY PROPERTY>", makeExemplars(additional)]);
+    }
+    const allChoices = resolveObjectChoices(fullObject, choices);
+    if (hasOptional) {
+        allChoices.push(emptyObject);
+    }
+    return allChoices;
+}
+
+function makeTupleExemplars(type: TupleType): readonly unknown[] {
+    const exemplars = type.getTypes().map((t) => makeExemplars(t));
+    function makeTuples(prefix: readonly unknown[], items: (readonly unknown[])[]): (readonly unknown[])[] {
+        if (items.length === 0) {
+            return [prefix];
+        }
+        const [head, ...tail] = items;
+        const results: (readonly unknown[])[] = [];
+        for (const choice of head) {
+            results.push(...makeTuples(prefix.concat([choice]), tail));
+        }
+        return results;
+    }
+
+    return makeTuples([], exemplars);
+}
diff --git a/test/utils.ts b/test/utils.ts
index 5c0a41ac4..b1e52b028 100644
--- a/test/utils.ts
+++ b/test/utils.ts
@@ -8,16 +8,88 @@ import { createFormatter } from "../factory/formatter";
 import { createParser } from "../factory/parser";
 import { createProgram } from "../factory/program";
 import { Config } from "../src/Config";
+import { Context } from "../src/NodeParser";
 import { SchemaGenerator } from "../src/SchemaGenerator";
+import { makeExemplars } from "../src/Utils/makeExemplar";
+import { inspect } from "util";
+import { BaseType } from "../src/Type/BaseType";
 
 const validator = new Ajv();
 addFormats(validator);
 
 const basePath = "test/valid-data";
 
-export function createGenerator(config: Config): SchemaGenerator {
-    const program: ts.Program = createProgram(config);
-    return new SchemaGenerator(program, createParser(program, config), createFormatter(config), config);
+interface Validator<T> {
+    (value: T): boolean | Promise<unknown>;
+    //                    ^^^^^^^^^^^^^^^^ *Why* does validateSchema() sometimes return this? Who knows! >.<
+}
+interface ErrorContainer {
+    errors?: { message?: string }[] | null;
+}
+
+expect.extend({
+    toValidateUsing<T>(
+        this: jest.MatcherContext,
+        received: T,
+        validationFunction: Validator<T>,
+        errorContainer?: ErrorContainer
+    ) {
+        errorContainer ??= validationFunction as ErrorContainer;
+        const previousErrors = errorContainer.errors;
+        errorContainer.errors = null;
+        try {
+            const result = validationFunction.call(errorContainer, received);
+            const errors = errorContainer.errors;
+            const pass = !!result && errors === null;
+            const options: jest.MatcherHintOptions = {
+                comment: "Schema validation",
+                isNot: this.isNot,
+                promise: this.promise,
+            };
+            const hint = () => this.utils.matcherHint("toValidateUsing", undefined, "validator", options) + "\n\n";
+            const printReceived = () => "\n\nReceived: " + this.utils.RECEIVED_COLOR(inspect(received));
+            return {
+                pass,
+                message: pass
+                    ? () => hint() + "Expected validation to fail, but it did not." + printReceived()
+                    : () =>
+                          hint() +
+                          "Expected validation to succeed, but it did not." +
+                          printReceived() +
+                          "\n\n" +
+                          `Errors: ${this.utils.EXPECTED_COLOR(inspect(errors))}`,
+            };
+        } finally {
+            errorContainer.errors = previousErrors;
+        }
+    },
+});
+declare global {
+    // eslint-disable-next-line @typescript-eslint/no-namespace
+    namespace jest {
+        interface Matchers<R, T> {
+            toValidateUsing(validatorMethod: Validator<T>, errorContainer: ErrorContainer): R;
+            toValidateUsing(validatorFunction: Validator<T> & ErrorContainer): R;
+        }
+    }
+}
+
+// Expose some of the SchemaGenerator internals for test use
+export class TestSchemaGenerator extends SchemaGenerator {
+    public readonly program: ts.Program;
+    constructor(config: Config) {
+        const program: ts.Program = createProgram(config);
+        super(program, createParser(program, config), createFormatter(config), config);
+    }
+
+    public getParsedType(fullName: string): BaseType {
+        const node = this.findNamedNode(fullName);
+        const type = this.nodeParser.createType(node, new Context());
+        if (!type) {
+            throw new Error(`Could not find or parse type ${fullName}`);
+        }
+        return type;
+    }
 }
 
 export function assertValidSchema(
@@ -26,6 +98,24 @@ export function assertValidSchema(
     jsDoc: Config["jsDoc"] = "none",
     extraTags?: Config["extraTags"],
     schemaId?: Config["schemaId"]
+): () => void {
+    return assertValidSchemaEx(relativePath, type, { jsDoc, extraTags, schemaId });
+}
+
+export function assertValidSchemaEx(
+    relativePath: string,
+    type?: string,
+    {
+        valid,
+        invalid,
+        jsDoc = "none",
+        extraTags,
+        schemaId,
+        ...configOptions
+    }: Config & {
+        valid?: string;
+        invalid?: string;
+    } = {}
 ) {
     return (): void => {
         const config: Config = {
@@ -34,13 +124,14 @@ export function assertValidSchema(
             jsDoc,
             extraTags,
             skipTypeCheck: !!process.env.FAST_TEST,
+            ...configOptions,
         };
 
         if (schemaId) {
             config.schemaId = schemaId;
         }
 
-        const generator = createGenerator(config);
+        const generator = new TestSchemaGenerator(config);
         const schema = generator.createSchema(type);
         const schemaFile = resolve(`${basePath}/${relativePath}/schema.json`);
 
@@ -60,8 +151,23 @@ export function assertValidSchema(
             addFormats(localValidator);
         }
 
-        localValidator.validateSchema(actual);
-        expect(localValidator.errors).toBeNull();
-        localValidator.compile(actual); // Will find MissingRef errors
+        expect(actual).toValidateUsing(localValidator.validateSchema, localValidator);
+        const validate = localValidator.compile(actual); // Will find MissingRef errors
+
+        if (valid) {
+            const validType = generator.getParsedType(valid);
+            const exemplars = makeExemplars(validType);
+            for (const ex of exemplars) {
+                expect(ex).toValidateUsing(validate);
+            }
+        }
+
+        if (invalid) {
+            const invalidType = generator.getParsedType(invalid);
+            const exemplars = makeExemplars(invalidType);
+            for (const ex of exemplars) {
+                expect(ex).not.toValidateUsing(validate);
+            }
+        }
     };
 }
diff --git a/test/valid-data-type.test.ts b/test/valid-data-type.test.ts
index 2c055dfdb..6e9151cc4 100644
--- a/test/valid-data-type.test.ts
+++ b/test/valid-data-type.test.ts
@@ -1,6 +1,9 @@
-import { assertValidSchema } from "./utils";
+import { assertValidSchema, assertValidSchemaEx } from "./utils";
 
 describe("valid-data-type", () => {
+    // default export names for the valid/invalid exemplar types
+    const valid = "VALID",
+        invalid = "INVALID";
     it("type-aliases-primitive", assertValidSchema("type-aliases-primitive", "MyString"));
     it(
         "type-aliases-primitive-with-id",
@@ -35,6 +38,10 @@ describe("valid-data-type", () => {
     it("type-regexp", assertValidSchema("type-regexp", "MyObject"));
     it("type-union", assertValidSchema("type-union", "TypeUnion"));
     it("type-union-tagged", assertValidSchema("type-union-tagged", "Shape"));
+    it(
+        "type-union-weird",
+        assertValidSchemaEx("type-union-weird", "WeirdUnion", { valid, invalid, jsDoc: "extended" })
+    );
     it("type-intersection", assertValidSchema("type-intersection", "MyObject"));
     it("type-intersection-conflict", assertValidSchema("type-intersection-conflict", "MyObject"));
     it("type-intersection-partial-conflict", assertValidSchema("type-intersection-partial-conflict", "MyType"));
diff --git a/test/valid-data/type-union-weird/main.ts b/test/valid-data/type-union-weird/main.ts
new file mode 100644
index 000000000..a7bfac8d2
--- /dev/null
+++ b/test/valid-data/type-union-weird/main.ts
@@ -0,0 +1,72 @@
+interface UnionElements {
+    /**
+     * Has a definition
+     */
+    stringWithDefinition: string;
+    /**
+     * Also has a definition
+     */
+    numberWithDefinition: number;
+    stringWithoutDefinition: string;
+    numberWithoutDefinition: number;
+    /**
+     * @minLength 10
+     */
+    stringWithMinLength: string;
+    /**
+     * @pattern ^\d+$
+     */
+    stringWithOnlyDigits: string;
+    /**
+     * @minimum 10
+     */
+    numberWithMinimum: number;
+    /**
+     * @maximum 5
+     */
+    numberWithMaximum: number;
+    enumString: 'a' | 'b' | 'c';
+    enumNumber: 1 | 2 | 3;
+}
+
+export interface WeirdUnion {
+    noCollapse1?: UnionElements['stringWithDefinition'] | UnionElements['numberWithDefinition'];
+    noCollapse2?: UnionElements['stringWithoutDefinition'] | UnionElements['enumNumber'];
+    noCollapse3?: UnionElements['numberWithoutDefinition'] | UnionElements['enumNumber'];
+    collapse1?: UnionElements['stringWithDefinition'] | UnionElements['numberWithoutDefinition'];
+    collapse2?: UnionElements['stringWithoutDefinition'] | UnionElements['numberWithoutDefinition'];
+    actuallyAnyString?: UnionElements['stringWithMinLength'] | UnionElements['stringWithoutDefinition'];
+    actuallyAnyNumber?: UnionElements['numberWithMaximum'] | UnionElements['numberWithoutDefinition'];
+    digitsOrLongString?: UnionElements['stringWithMinLength'] | UnionElements['stringWithOnlyDigits'];
+    digitsOrNumber?: UnionElements['stringWithOnlyDigits'] | UnionElements['numberWithDefinition'];
+    numberWithMinOrMax?: UnionElements['numberWithMinimum'] | UnionElements['numberWithMaximum'];
+}
+
+const validList = [
+    {
+        actuallyAnyString: 'short',
+        actuallyAnyNumber: 1234,
+        digitsOrLongString: '1234',
+        digitsOrNumber: '1234',
+        numberWithMinOrMax: 0,
+    },
+    {
+        digitsOrLongString: 'veryverylong',
+        digitsOrNumber: 1234,
+        numberWithMinOrMax: 1234,
+    },
+] as const;
+export const invalidList = [
+    {
+        digitsOrLongString: 'short',
+    },
+    {
+        digitsOrNumber: 'word',
+    },
+    {
+        numberWithMinOrMax: 7,
+    }
+] as const;
+
+export type VALID = typeof validList[number];
+export type INVALID = typeof invalidList[number];
diff --git a/test/valid-data/type-union-weird/schema.json b/test/valid-data/type-union-weird/schema.json
new file mode 100644
index 000000000..9f6229b91
--- /dev/null
+++ b/test/valid-data/type-union-weird/schema.json
@@ -0,0 +1,112 @@
+{
+  "$ref": "#/definitions/WeirdUnion",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "WeirdUnion": {
+      "additionalProperties": false,
+      "properties": {
+        "actuallyAnyNumber": {
+          "anyOf": [
+            {
+              "maximum": 5,
+              "type": "number"
+            },
+            {
+              "type": "number"
+            }
+          ]
+        },
+        "actuallyAnyString": {
+          "type": "string"
+        },
+        "collapse1": {
+          "description": "Has a definition",
+          "type": [
+            "string",
+            "number"
+          ]
+        },
+        "collapse2": {
+          "type": [
+            "string",
+            "number"
+          ]
+        },
+        "digitsOrLongString": {
+          "type": "string"
+        },
+        "digitsOrNumber": {
+          "description": "Also has a definition",
+          "pattern": "^\\d+$",
+          "type": [
+            "string",
+            "number"
+          ]
+        },
+        "noCollapse1": {
+          "anyOf": [
+            {
+              "description": "Has a definition",
+              "type": "string"
+            },
+            {
+              "description": "Also has a definition",
+              "type": "number"
+            }
+          ]
+        },
+        "noCollapse2": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "const": 1,
+              "type": "number"
+            },
+            {
+              "const": 2,
+              "type": "number"
+            },
+            {
+              "const": 3,
+              "type": "number"
+            }
+          ]
+        },
+        "noCollapse3": {
+          "anyOf": [
+            {
+              "type": "number"
+            },
+            {
+              "const": 1,
+              "type": "number"
+            },
+            {
+              "const": 2,
+              "type": "number"
+            },
+            {
+              "const": 3,
+              "type": "number"
+            }
+          ]
+        },
+        "numberWithMinOrMax": {
+          "anyOf": [
+            {
+              "minimum": 10,
+              "type": "number"
+            },
+            {
+              "maximum": 5,
+              "type": "number"
+            }
+          ]
+        }
+      },
+      "type": "object"
+    }
+  }
+}
diff --git a/test/vega-lite.test.ts b/test/vega-lite.test.ts
index 529707330..0a174dc61 100644
--- a/test/vega-lite.test.ts
+++ b/test/vega-lite.test.ts
@@ -1,7 +1,7 @@
 import { readFileSync, writeFileSync } from "fs";
 import { resolve } from "path";
 import { Config } from "../src/Config";
-import { createGenerator } from "./utils";
+import { TestSchemaGenerator } from "./utils";
 import stringify from "json-stable-stringify";
 import Ajv from "ajv";
 import addFormats from "ajv-formats";
@@ -16,7 +16,7 @@ describe("vega-lite", () => {
             skipTypeCheck: true,
         };
 
-        const generator = createGenerator(config);
+        const generator = new TestSchemaGenerator(config);
         const schema = generator.createSchema(type);
         const schemaFile = resolve("test/vega-lite/schema.json");
 

From 58f0dc9f8dafa887884c5af16f07b4403a6940a0 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Sat, 27 Mar 2021 21:40:08 -0400
Subject: [PATCH 6/7] Adding enum-merging to mergeDefinitions, unit test

---
 src/Utils/mergeDefinitions.ts                |  52 ++++-
 test/unit/mergeDefinitions.test.ts           |  62 ++++++
 test/valid-data/type-union-weird/schema.json |  36 ++--
 test/vega-lite/schema.json                   | 197 ++++++++++---------
 4 files changed, 223 insertions(+), 124 deletions(-)
 create mode 100644 test/unit/mergeDefinitions.test.ts

diff --git a/src/Utils/mergeDefinitions.ts b/src/Utils/mergeDefinitions.ts
index 749392a27..cee07fa8c 100644
--- a/src/Utils/mergeDefinitions.ts
+++ b/src/Utils/mergeDefinitions.ts
@@ -1,5 +1,4 @@
 import { Definition } from "../Schema/Definition";
-import { uniqueArray } from "./uniqueArray";
 
 /**
  * Attempt to merge two disjoint definitions into one. Definitions are disjoint
@@ -8,18 +7,55 @@ import { uniqueArray } from "./uniqueArray";
  * 2) The cross-type validation properties 'enum' and 'const' are not on either definition, and
  * 3) The two definitions have no properties besides 'type' in common.
  *
+ * OR, if the following are true:
+ * 1) Each has an 'enum' or 'const' property (which is treated as an enum with one element)
+ * 2) They both have a 'type' property (which will be merged and deduplicated) or both do not
+ * 3) They share no other properties besides, possibly, 'type'
  * Returns the merged definition, or null if the two defs were not disjoint.
  */
 export function mergeDefinitions(def1: Definition, def2: Definition): Definition | null {
-    const { type: type1, ...props1 } = def1;
-    const { type: type2, ...props2 } = def2;
-    const types = [type1!, type2!].flat();
-    if (!type1 || !type2 || uniqueArray(types).length !== types.length) {
+    if (def1.$ref || def2.$ref) {
+        // pointer definitions are never mergeable
         return null;
     }
-    const keys = [...Object.keys(props1), ...Object.keys(props2)];
-    if (keys.includes("enum") || keys.includes("const") || uniqueArray(keys).length !== keys.length) {
+    const { type: type1, enum: enum1, props: props1 } = splitTypesAndEnums(def1);
+    const { type: type2, enum: enum2, props: props2 } = splitTypesAndEnums(def2);
+    const result: Definition = {
+        ...props1,
+        ...props2,
+    };
+
+    if (Object.keys(result).length !== Object.keys(props1).length + Object.keys(props2).length) {
+        // shared properties - unmergeable
+        return null;
+    }
+
+    if (enum1 && enum2) {
+        if (type1 && type2) {
+            result.type = Array.from(new Set(type1.concat(type2)));
+        } else if (type1 || type2) {
+            // one is typed and one isn't - unmergeable
+            return null;
+        }
+        result.enum = Array.from(new Set(enum1.concat(enum2)));
+    } else if (type1 && type2 && !enum1 && !enum2) {
+        if (type1.some((t) => type2.includes(t))) {
+            // shared types - unmergeable
+            return null;
+        }
+        result.type = type1.concat(type2);
+    } else {
         return null;
     }
-    return { type: types, ...props1, ...props2 };
+
+    return result;
+}
+
+function splitTypesAndEnums(def: Definition) {
+    const { type: _type, const: _const, enum: _enum, ...props } = def;
+    return {
+        type: typeof _type === "string" ? [_type] : _type,
+        enum: typeof _const !== "undefined" ? [_const] : _enum,
+        props,
+    };
 }
diff --git a/test/unit/mergeDefinitions.test.ts b/test/unit/mergeDefinitions.test.ts
new file mode 100644
index 000000000..529fd2048
--- /dev/null
+++ b/test/unit/mergeDefinitions.test.ts
@@ -0,0 +1,62 @@
+import { Definition } from "../../src/Schema/Definition";
+import { mergeDefinitions } from "../../src/Utils/mergeDefinitions";
+
+function assertMerges(def1: Definition, def2: Definition, expected?: Definition) {
+    return () => {
+        const actual = mergeDefinitions(def1, def2);
+        if (expected) {
+            expect(actual).toEqual(expected);
+        } else {
+            expect(actual).not.toBeNull();
+        }
+        const allKeys = Array.from(new Set(Object.keys(def1).concat(Object.keys(def2))));
+        if (allKeys.includes("const")) {
+            // 'const' keys turn into 'enum' keys
+            allKeys.splice(allKeys.indexOf("const"), 1);
+            if (!allKeys.includes("enum")) {
+                allKeys.push("enum");
+            }
+        }
+        expect(Object.keys(actual).sort()).toEqual(allKeys.sort());
+    };
+}
+
+function assertDoesNotMerge(def1: Definition, def2: Definition) {
+    return () => {
+        const actual = mergeDefinitions(def1, def2);
+        expect(actual).toBeNull();
+    };
+}
+
+describe("mergeDefinitions", () => {
+    it(
+        "merges simple unlike types",
+        assertMerges({ type: "string" }, { type: "number" }, { type: ["string", "number"] })
+    );
+    it("does not merge identical types", assertDoesNotMerge({ type: "number" }, { type: "number" }));
+    it(
+        "merges complex unlike types",
+        assertMerges({ type: "object", additionalProperties: false }, { type: "array", additionalItems: false })
+    );
+    it(
+        "does not merge types that share properties",
+        assertDoesNotMerge({ type: "string", description: "a string" }, { type: "number", description: "a number" })
+    );
+    it("merges consts into an enum", assertMerges({ const: "one" }, { const: "two" }, { enum: ["one", "two"] }));
+    it("merges const into existing enum", assertMerges({ enum: [1, 2] }, { const: 3 }, { enum: [1, 2, 3] }));
+    it("merges two enums", assertMerges({ enum: [1, 2] }, { enum: [3, 4] }, { enum: [1, 2, 3, 4] }));
+    it("dedupes merged enums", assertMerges({ enum: [1, 2] }, { enum: [2, 3] }, { enum: [1, 2, 3] }));
+    it(
+        "merges types in merged enums",
+        assertMerges(
+            { const: "one", type: "string" },
+            { const: 2, type: "number" },
+            { enum: ["one", 2], type: ["string", "number"] }
+        )
+    );
+    it(
+        "does not merge enums that share properties",
+        assertDoesNotMerge({ const: 1, description: "#1" }, { const: "two", description: "#2" })
+    );
+    it("does not merge an enum with a non-enum", assertDoesNotMerge({ const: 1 }, { type: "string" }));
+});
diff --git a/test/valid-data/type-union-weird/schema.json b/test/valid-data/type-union-weird/schema.json
index 9f6229b91..50acccb21 100644
--- a/test/valid-data/type-union-weird/schema.json
+++ b/test/valid-data/type-union-weird/schema.json
@@ -61,16 +61,14 @@
               "type": "string"
             },
             {
-              "const": 1,
-              "type": "number"
-            },
-            {
-              "const": 2,
-              "type": "number"
-            },
-            {
-              "const": 3,
-              "type": "number"
+              "enum": [
+                1,
+                2,
+                3
+              ],
+              "type": [
+                "number"
+              ]
             }
           ]
         },
@@ -80,16 +78,14 @@
               "type": "number"
             },
             {
-              "const": 1,
-              "type": "number"
-            },
-            {
-              "const": 2,
-              "type": "number"
-            },
-            {
-              "const": 3,
-              "type": "number"
+              "enum": [
+                1,
+                2,
+                3
+              ],
+              "type": [
+                "number"
+              ]
             }
           ]
         },
diff --git a/test/vega-lite/schema.json b/test/vega-lite/schema.json
index 60a968ace..615024fbf 100644
--- a/test/vega-lite/schema.json
+++ b/test/vega-lite/schema.json
@@ -12111,12 +12111,13 @@
           "type": "boolean"
         },
         {
-          "const": "parity",
-          "type": "string"
-        },
-        {
-          "const": "greedy",
-          "type": "string"
+          "enum": [
+            "parity",
+            "greedy"
+          ],
+          "type": [
+            "string"
+          ]
         }
       ]
     },
@@ -18404,20 +18405,15 @@
           ]
         },
         {
-          "const": "string",
-          "type": "string"
-        },
-        {
-          "const": "boolean",
-          "type": "string"
-        },
-        {
-          "const": "date",
-          "type": "string"
-        },
-        {
-          "const": "number",
-          "type": "string"
+          "enum": [
+            "string",
+            "boolean",
+            "date",
+            "number"
+          ],
+          "type": [
+            "string"
+          ]
         }
       ]
     },
@@ -22947,12 +22943,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23110,12 +23107,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23424,12 +23422,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23510,12 +23509,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -24766,12 +24766,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -24852,12 +24853,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25161,12 +25163,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25247,12 +25250,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25507,12 +25511,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25593,12 +25598,13 @@
                   "type": "number"
                 },
                 {
-                  "const": "width",
-                  "type": "string"
-                },
-                {
-                  "const": "height",
-                  "type": "string"
+                  "enum": [
+                    "width",
+                    "height"
+                  ],
+                  "type": [
+                    "string"
+                  ]
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -26222,19 +26228,17 @@
     "TextBaseline": {
       "anyOf": [
         {
-          "const": "alphabetic",
-          "type": "string"
+          "enum": [
+            "alphabetic",
+            "line-top",
+            "line-bottom"
+          ],
+          "type": [
+            "string"
+          ]
         },
         {
           "$ref": "#/definitions/Baseline"
-        },
-        {
-          "const": "line-top",
-          "type": "string"
-        },
-        {
-          "const": "line-bottom",
-          "type": "string"
         }
       ]
     },
@@ -29345,12 +29349,13 @@
               "type": "number"
             },
             {
-              "const": "width",
-              "type": "string"
-            },
-            {
-              "const": "height",
-              "type": "string"
+              "enum": [
+                "width",
+                "height"
+              ],
+              "type": [
+                "string"
+              ]
             },
             {
               "$ref": "#/definitions/ExprRef"

From 79d185559857554e039e99a65a97ebbc1f56e852 Mon Sep 17 00:00:00 2001
From: Danielle Church <dani.church@gmail.com>
Date: Sun, 28 Mar 2021 00:35:29 -0400
Subject: [PATCH 7/7] mergeDefinitions works on trivially-mergable types

In a few simple cases like (1 | number), mergeDefinitions will now
correctly collapse two not-quite-disjoint type definitions together,
by discarding the validation restrictions on the more-restricted type.
This replaces the string-merging logic in UnionTypeFormatter, which
was discarding annotations.
---
 src/TypeFormatter/UnionTypeFormatter.ts      |  19 ---
 src/Utils/mergeDefinitions.ts                | 152 +++++++++++++++++--
 test/unit/mergeDefinitions.test.ts           |  51 +++++--
 test/valid-data/type-union-weird/main.ts     |   2 +-
 test/valid-data/type-union-weird/schema.json |  43 ++----
 test/vega-lite/schema.json                   |  73 ++-------
 6 files changed, 212 insertions(+), 128 deletions(-)

diff --git a/src/TypeFormatter/UnionTypeFormatter.ts b/src/TypeFormatter/UnionTypeFormatter.ts
index 49786aba0..3682e0fbd 100644
--- a/src/TypeFormatter/UnionTypeFormatter.ts
+++ b/src/TypeFormatter/UnionTypeFormatter.ts
@@ -16,25 +16,6 @@ export class UnionTypeFormatter implements SubTypeFormatter {
     public getDefinition(type: UnionType): Definition {
         const definitions = type.getTypes().map((item) => this.childTypeFormatter.getDefinition(item));
 
-        // TODO: why is this not covered by LiteralUnionTypeFormatter?
-        // special case for string literals | string -> string
-        let stringType = true;
-        let oneNotEnum = false;
-        for (const def of definitions) {
-            if (def.type !== "string") {
-                stringType = false;
-                break;
-            }
-            if (def.enum === undefined) {
-                oneNotEnum = true;
-            }
-        }
-        if (stringType && oneNotEnum) {
-            return {
-                type: "string",
-            };
-        }
-
         const flattenedDefinitions: JSONSchema7[] = [];
 
         // Flatten anyOf inside anyOf unless the anyOf has an annotation
diff --git a/src/Utils/mergeDefinitions.ts b/src/Utils/mergeDefinitions.ts
index cee07fa8c..5bb06ccaf 100644
--- a/src/Utils/mergeDefinitions.ts
+++ b/src/Utils/mergeDefinitions.ts
@@ -1,4 +1,9 @@
 import { Definition } from "../Schema/Definition";
+import { RawTypeName } from "../Schema/RawType";
+
+const isIntegerKey = "\0isInteger";
+type _Definition = Definition & { [isIntegerKey]?: true };
+type DefinitionProp = keyof _Definition;
 
 /**
  * Attempt to merge two disjoint definitions into one. Definitions are disjoint
@@ -20,14 +25,33 @@ export function mergeDefinitions(def1: Definition, def2: Definition): Definition
     }
     const { type: type1, enum: enum1, props: props1 } = splitTypesAndEnums(def1);
     const { type: type2, enum: enum2, props: props2 } = splitTypesAndEnums(def2);
-    const result: Definition = {
-        ...props1,
-        ...props2,
-    };
+    const result: _Definition = {};
 
-    if (Object.keys(result).length !== Object.keys(props1).length + Object.keys(props2).length) {
-        // shared properties - unmergeable
-        return null;
+    const def1Validations: Partial<Record<RawTypeName, _Definition>> = {};
+    const def2Validations: Partial<Record<RawTypeName, _Definition>> = {};
+    for (const [props, validations] of [
+        [props1, def1Validations],
+        [props2, def2Validations],
+    ] as const) {
+        for (const prop of Object.keys(props) as DefinitionProp[]) {
+            const value = props[prop];
+            const propValidationType = propertyValidationMap[prop];
+            if (!propValidationType) {
+                // assume this is a general validation property, bail
+                return null;
+            }
+            if (prop in result && value !== result[prop]) {
+                // shared annotation without identical values, unmergeable
+                return null;
+            }
+            if (typeof propValidationType === "string") {
+                validations[propValidationType] ??= {};
+                // Typescript gets sad about how many properties there are.
+                (validations[propValidationType] as any)[prop] = value;
+            } else {
+                (result as any)[prop] = value;
+            }
+        }
     }
 
     if (enum1 && enum2) {
@@ -38,24 +62,126 @@ export function mergeDefinitions(def1: Definition, def2: Definition): Definition
             return null;
         }
         result.enum = Array.from(new Set(enum1.concat(enum2)));
+    } else if (
+        enum1 &&
+        !enum2 &&
+        type1?.every((t) => type2?.includes(t) && !def1Validations[t] && !def2Validations[t])
+    ) {
+        // enum vs non-enum - can be collapsed if the non-enum shares type and there are no validations
+        result.type = type2;
+    } else if (
+        enum2 &&
+        !enum1 &&
+        type2?.every((t) => type1?.includes(t) && !def1Validations[t] && !def2Validations[t])
+    ) {
+        result.type = type1;
     } else if (type1 && type2 && !enum1 && !enum2) {
-        if (type1.some((t) => type2.includes(t))) {
-            // shared types - unmergeable
-            return null;
+        const allTypes = Array.from(new Set(type1.concat(type2)));
+        // Check every type represented in either def. Possibilities are:
+        // 1) Included in only one def. Include validations from that def.
+        // 2) Included in both defs, with validations in only one. Include without validations.
+        // 3) Included in both defs, validations in one are a strict subset of the other. Include the less-constrained.
+        // 4) Incompatible validations. Bail.
+        for (const type of allTypes) {
+            const typeValidations1 = def1Validations[type];
+            const typeValidations2 = def2Validations[type];
+            let useValidations: _Definition | undefined;
+            if (!type1.includes(type)) {
+                useValidations = typeValidations2;
+            } else if (!type2.includes(type)) {
+                useValidations = typeValidations1;
+            } else if (!typeValidations1 || !typeValidations2) {
+                // No validations, since we know both defs have the type
+            } else if (
+                Object.entries(typeValidations1).every(([k, v]) => typeValidations2[k as DefinitionProp] === v)
+            ) {
+                // typeValidations1 is a strict subset of typeValidations2
+                useValidations = typeValidations1;
+            } else if (
+                Object.entries(typeValidations2).every(([k, v]) => typeValidations1[k as DefinitionProp] === v)
+            ) {
+                // typeValidations2 is a strict subset of typeValidations1
+                useValidations = typeValidations2;
+            } else {
+                // incompatible validations for this type
+                return null;
+            }
+            if (useValidations) {
+                Object.assign(result, useValidations);
+            }
         }
-        result.type = type1.concat(type2);
+        result.type = allTypes;
     } else {
         return null;
     }
 
+    if (result[isIntegerKey]) {
+        if (Array.isArray(result.type) && result.type.includes("number")) {
+            result.type[result.type.indexOf("number")] = "integer";
+        }
+        delete result[isIntegerKey];
+    }
+
+    if (Array.isArray(result.type) && result.type.length === 1) {
+        result.type = result.type[0];
+    }
+
     return result;
 }
 
 function splitTypesAndEnums(def: Definition) {
     const { type: _type, const: _const, enum: _enum, ...props } = def;
-    return {
+    const result = {
         type: typeof _type === "string" ? [_type] : _type,
         enum: typeof _const !== "undefined" ? [_const] : _enum,
-        props,
+        props: props as _Definition,
     };
+    if (result.type?.includes("integer")) {
+        // type integer is effectively a constraint on type number. Treat it as such for now.
+        if (!result.type.includes("number")) {
+            result.type.push("number");
+        }
+        result.props[isIntegerKey] = true;
+    }
+    return result;
 }
+
+const typeValidations: Record<RawTypeName, DefinitionProp[]> = {
+    array: ["items", "additionalItems", "maxItems", "minItems", "uniqueItems", "contains"],
+    boolean: [],
+    integer: [],
+    null: [],
+    number: ["multipleOf", "maximum", "exclusiveMaximum", "minimum", "exclusiveMinimum", isIntegerKey],
+    object: [
+        "maxProperties",
+        "minProperties",
+        "required",
+        "properties",
+        "patternProperties",
+        "additionalProperties",
+        "dependencies",
+        "propertyNames",
+    ],
+    string: ["maxLength", "minLength", "pattern"],
+};
+
+const knownAnnotations: DefinitionProp[] = [
+    "title",
+    "description",
+    "default",
+    "readOnly",
+    "writeOnly",
+    "examples",
+    "$comment",
+    "contentEncoding",
+    "contentMediaType",
+];
+
+// Anything that isn't in one of the above lists is assumed to be a general validation keyword
+const propertyValidationMap: Partial<Record<DefinitionProp, RawTypeName | true>> = Object.fromEntries(
+    knownAnnotations
+        .map((prop) => [prop, true as RawTypeName | true])
+        .concat(
+            ...Object.entries(typeValidations).map(([type, props]) => props.map((prop) => [prop, type as RawTypeName]))
+        )
+);
diff --git a/test/unit/mergeDefinitions.test.ts b/test/unit/mergeDefinitions.test.ts
index 529fd2048..1037a2849 100644
--- a/test/unit/mergeDefinitions.test.ts
+++ b/test/unit/mergeDefinitions.test.ts
@@ -8,16 +8,16 @@ function assertMerges(def1: Definition, def2: Definition, expected?: Definition)
             expect(actual).toEqual(expected);
         } else {
             expect(actual).not.toBeNull();
-        }
-        const allKeys = Array.from(new Set(Object.keys(def1).concat(Object.keys(def2))));
-        if (allKeys.includes("const")) {
-            // 'const' keys turn into 'enum' keys
-            allKeys.splice(allKeys.indexOf("const"), 1);
-            if (!allKeys.includes("enum")) {
-                allKeys.push("enum");
+            const allKeys = Array.from(new Set(Object.keys(def1).concat(Object.keys(def2))));
+            if (allKeys.includes("const")) {
+                // 'const' keys turn into 'enum' keys
+                allKeys.splice(allKeys.indexOf("const"), 1);
+                if (!allKeys.includes("enum")) {
+                    allKeys.push("enum");
+                }
             }
+            expect(Object.keys(actual).sort()).toEqual(allKeys.sort());
         }
-        expect(Object.keys(actual).sort()).toEqual(allKeys.sort());
     };
 }
 
@@ -33,7 +33,6 @@ describe("mergeDefinitions", () => {
         "merges simple unlike types",
         assertMerges({ type: "string" }, { type: "number" }, { type: ["string", "number"] })
     );
-    it("does not merge identical types", assertDoesNotMerge({ type: "number" }, { type: "number" }));
     it(
         "merges complex unlike types",
         assertMerges({ type: "object", additionalProperties: false }, { type: "array", additionalItems: false })
@@ -59,4 +58,38 @@ describe("mergeDefinitions", () => {
         assertDoesNotMerge({ const: 1, description: "#1" }, { const: "two", description: "#2" })
     );
     it("does not merge an enum with a non-enum", assertDoesNotMerge({ const: 1 }, { type: "string" }));
+
+    it(
+        "merges types with identical annotations",
+        assertMerges(
+            { type: "string", title: "title" },
+            { type: "number", title: "title" },
+            { type: ["string", "number"], title: "title" }
+        )
+    );
+    it(
+        "merges same types with no validations",
+        assertMerges({ type: "string" }, { type: "string" }, { type: "string" })
+    );
+    it(
+        "merges same types with identical validations",
+        assertMerges(
+            { type: "string", minLength: 5 },
+            { type: "string", minLength: 5 },
+            { type: "string", minLength: 5 }
+        )
+    );
+    it(
+        "does not merge same types with different validations",
+        assertDoesNotMerge({ type: "string", minLength: 5 }, { type: "string", maxLength: 10 })
+    );
+    it(
+        "collapses types with validations into types without",
+        assertMerges({ type: "string" }, { type: "string", minLength: 5 }, { type: "string" })
+    );
+    it(
+        "collapses types with enums into types without validations",
+        assertMerges({ type: "number" }, { type: "number", const: 7 }, { type: "number" })
+    );
+    it("does not merge when general validations are present", assertDoesNotMerge({ type: "string" }, { anyOf: [] }));
 });
diff --git a/test/valid-data/type-union-weird/main.ts b/test/valid-data/type-union-weird/main.ts
index a7bfac8d2..1841ddd61 100644
--- a/test/valid-data/type-union-weird/main.ts
+++ b/test/valid-data/type-union-weird/main.ts
@@ -32,9 +32,9 @@ interface UnionElements {
 export interface WeirdUnion {
     noCollapse1?: UnionElements['stringWithDefinition'] | UnionElements['numberWithDefinition'];
     noCollapse2?: UnionElements['stringWithoutDefinition'] | UnionElements['enumNumber'];
-    noCollapse3?: UnionElements['numberWithoutDefinition'] | UnionElements['enumNumber'];
     collapse1?: UnionElements['stringWithDefinition'] | UnionElements['numberWithoutDefinition'];
     collapse2?: UnionElements['stringWithoutDefinition'] | UnionElements['numberWithoutDefinition'];
+    collapse3?: UnionElements['numberWithoutDefinition'] | UnionElements['enumNumber'];
     actuallyAnyString?: UnionElements['stringWithMinLength'] | UnionElements['stringWithoutDefinition'];
     actuallyAnyNumber?: UnionElements['numberWithMaximum'] | UnionElements['numberWithoutDefinition'];
     digitsOrLongString?: UnionElements['stringWithMinLength'] | UnionElements['stringWithOnlyDigits'];
diff --git a/test/valid-data/type-union-weird/schema.json b/test/valid-data/type-union-weird/schema.json
index 50acccb21..03d4fb902 100644
--- a/test/valid-data/type-union-weird/schema.json
+++ b/test/valid-data/type-union-weird/schema.json
@@ -6,15 +6,7 @@
       "additionalProperties": false,
       "properties": {
         "actuallyAnyNumber": {
-          "anyOf": [
-            {
-              "maximum": 5,
-              "type": "number"
-            },
-            {
-              "type": "number"
-            }
-          ]
+          "type": "number"
         },
         "actuallyAnyString": {
           "type": "string"
@@ -32,8 +24,20 @@
             "number"
           ]
         },
+        "collapse3": {
+          "type": "number"
+        },
         "digitsOrLongString": {
-          "type": "string"
+          "anyOf": [
+            {
+              "minLength": 10,
+              "type": "string"
+            },
+            {
+              "pattern": "^\\d+$",
+              "type": "string"
+            }
+          ]
         },
         "digitsOrNumber": {
           "description": "Also has a definition",
@@ -66,26 +70,7 @@
                 2,
                 3
               ],
-              "type": [
-                "number"
-              ]
-            }
-          ]
-        },
-        "noCollapse3": {
-          "anyOf": [
-            {
               "type": "number"
-            },
-            {
-              "enum": [
-                1,
-                2,
-                3
-              ],
-              "type": [
-                "number"
-              ]
             }
           ]
         },
diff --git a/test/vega-lite/schema.json b/test/vega-lite/schema.json
index 615024fbf..fc6b55dec 100644
--- a/test/vega-lite/schema.json
+++ b/test/vega-lite/schema.json
@@ -12115,9 +12115,7 @@
             "parity",
             "greedy"
           ],
-          "type": [
-            "string"
-          ]
+          "type": "string"
         }
       ]
     },
@@ -18397,24 +18395,9 @@
       "type": "object"
     },
     "ParseValue": {
-      "anyOf": [
-        {
-          "type": [
-            "null",
-            "string"
-          ]
-        },
-        {
-          "enum": [
-            "string",
-            "boolean",
-            "date",
-            "number"
-          ],
-          "type": [
-            "string"
-          ]
-        }
+      "type": [
+        "null",
+        "string"
       ]
     },
     "PivotTransform": {
@@ -22947,9 +22930,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23111,9 +23092,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23426,9 +23405,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -23513,9 +23490,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -24770,9 +24745,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -24857,9 +24830,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25167,9 +25138,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25254,9 +25223,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25515,9 +25482,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -25602,9 +25567,7 @@
                     "width",
                     "height"
                   ],
-                  "type": [
-                    "string"
-                  ]
+                  "type": "string"
                 },
                 {
                   "$ref": "#/definitions/ExprRef"
@@ -26233,9 +26196,7 @@
             "line-top",
             "line-bottom"
           ],
-          "type": [
-            "string"
-          ]
+          "type": "string"
         },
         {
           "$ref": "#/definitions/Baseline"
@@ -29353,9 +29314,7 @@
                 "width",
                 "height"
               ],
-              "type": [
-                "string"
-              ]
+              "type": "string"
             },
             {
               "$ref": "#/definitions/ExprRef"