Fix handling decorators for union variants in JSONSchema emitter

.chronus/changes/feat-fix-union-variant-decorators-2024-4-20-14-27-15.md

@@ -0,0 +1,7 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: internal
+packages:
+ - "@typespec/compiler"
+---
+Doc 

.chronus/changes/feat-fix-union-variant-decorators-2024-4-20-14-48-3.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+ - "@typespec/json-schema"
+---
+
+Fix decorators application for union variants

packages/compiler/src/emitter-framework/type-emitter.ts

@@ -118,7 +118,7 @@ export type EmitterOutput<T> = EmitEntity<T> | Placeholder<T> | T;
  * literals, and any type referenced inside anywhere inside the model and any
  * of the referenced types' references.
  *
- * In both cases, context is an object. It strongly recommended that the context
+ * In both cases, context is an object. It's strongly recommended that the context
  * object either contain only primitive types, or else only reference immutable
  * objects.
  *

packages/json-schema/src/json-schema-emitter.ts

@@ -1,7 +1,6 @@
 import {
  BooleanLiteral,
  DiagnosticTarget,
- DuplicateTracker,
  Enum,
  EnumMember,
  IntrinsicType,
@@ -52,6 +51,7 @@ import {
  SourceFileScope,
  TypeEmitter,
 } from "@typespec/compiler/emitter-framework";
+import { DuplicateTracker } from "@typespec/compiler/utils";
 import { stringify } from "yaml";
 import {
  JsonSchemaDeclaration,
@@ -328,7 +328,14 @@ export class JsonSchemaEmitter extends TypeEmitter<Record<string, any>, JSONSche
  }
 
  unionVariant(variant: UnionVariant): EmitterOutput<object> {
- return this.emitter.emitTypeReference(variant.type);
+ const variantType = this.emitter.emitTypeReference(variant.type);
+ compilerAssert(variantType.kind === "code", "Unexpected non-code result from emit reference");
+
+ const result = new ObjectBuilder(variantType.value);
+
+ this.#applyConstraints(variant, result);
+
+ return result;
  }
 
  modelPropertyReference(property: ModelProperty): EmitterOutput<object> {
@@ -513,7 +520,7 @@ export class JsonSchemaEmitter extends TypeEmitter<Record<string, any>, JSONSche
  }
 
  #applyConstraints(
- type: Scalar | Model | ModelProperty | Union | Enum,
+ type: Scalar | Model | ModelProperty | Union | UnionVariant | Enum,
  schema: ObjectBuilder<unknown>
  ) {
  const applyConstraint = (fn: (p: Program, t: Type) => any, key: string) => {

packages/json-schema/test/unions.test.ts

@@ -87,4 +87,39 @@ describe("emitting unions", () => {
  const Foo = schemas["Foo.json"];
  assert.strictEqual(Foo["x-foo"], true);
  });
+
+ it("handles decorators on variants", async () => {
+ const schemas = await emitSchema(`
+ union Foo {
+ @doc("doc text")
+ @summary("summary text")
+ @extension("x-key", Json<"x-value">)
+ bar: string;
+
+ @doc("other model doc")
+ @summary("other model summary")
+ @extension("x-key-2", Json<"x-value-2">)
+ baz: OtherModel;
+ }
+
+ model OtherModel {}
+ `);
+
+ const Foo = schemas["Foo.json"];
+
+ assert.deepStrictEqual(Foo.anyOf, [
+ {
+ description: "doc text",
+ title: "summary text",
+ type: "string",
+ "x-key": "x-value",
+ },
+ {
+ $ref: "OtherModel.json",
+ description: "other model doc",
+ title: "other model summary",
+ "x-key-2": "x-value-2",
+ },
+ ]);
+ });
 });