feat: support self references (#443)

`key` cannot be a function since [`validateName`](https://github.com/jquense/yup/blob/d02ff5e59e004b4c5189d1b9fc0055cff45c61df/src/Reference.js#L3) ensures that it is a string.

`isSelf` is not used anywhere and `key="."` isn't supported by `property-expr` getter.

For working self references i opened [pull request](jquense/expr#9) in `property-expr` to support empty string path. (currently `getter("")` works, but `getter("", true)` which is used in Reference.js throws)

src/Condition.js

@@ -40,13 +40,9 @@ class Conditional {
     }
   }
 
-  getValue(parent, context) {
-    let values = this.refs.map(r => r.getValue(parent, context));
+  resolve(ctx, options) {
+    let values = this.refs.map(ref => ref.getValue(options));
 
-    return values;
-  }
-
-  resolve(ctx, values) {
     let schema = this.fn.apply(ctx, values.concat(ctx));
 
     if (schema !== undefined && !isSchema(schema))

src/Reference.js

@@ -1,48 +1,69 @@
 import { getter } from 'property-expr';
 
-let validateName = d => {
-  if (typeof d !== 'string')
-    throw new TypeError("ref's must be strings, got: " + d);
+const prefixes = {
+  context: '$',
+  value: '.',
 };
 
 export default class Reference {
-  static isRef(value) {
-    return !!(value && (value.__isYupRef || value instanceof Reference));
-  }
+  constructor(key, options = {}) {
+    if (typeof key !== 'string')
+      throw new TypeError('ref must be a string, got: ' + key);
 
-  toString() {
-    return `Ref(${this.key})`;
+    this.key = key.trim();
+
+    if (key === '') throw new TypeError('ref must be a non-empty string');
+
+    this.isContext = this.key[0] === prefixes.context;
+    this.isValue = this.key[0] === prefixes.value;
+    this.isSibling = !this.isContext && !this.isValue;
+
+    let prefix = this.isContext
+      ? prefixes.context
+      : this.isValue
+        ? prefixes.value
+        : '';
+
+    this.path = this.key.slice(prefix.length);
+    this.getter = this.path && getter(this.path, true);
+    this.map = options.map;
   }
 
-  constructor(key, mapFn, options = {}) {
-    validateName(key);
-    let prefix = options.contextPrefix || '$';
+  getValue(options) {
+    let result = this.isContext
+      ? options.context
+      : this.isValue
+        ? options.value
+        : options.parent;
 
-    if (typeof key === 'function') {
-      key = '.';
-    }
+    if (this.getter) result = this.getter(result || {});
 
-    this.key = key.trim();
-    this.prefix = prefix;
-    this.isContext = this.key.indexOf(prefix) === 0;
-    this.isSelf = this.key === '.';
+    if (this.map) result = this.map(result);
+
+    return result;
+  }
 
-    this.path = this.isContext ? this.key.slice(this.prefix.length) : this.key;
-    this._get = getter(this.path, true);
-    this.map = mapFn || (value => value);
+  cast(value, options) {
+    return this.getValue({ ...options, value });
   }
+
   resolve() {
     return this;
   }
 
-  cast(value, { parent, context }) {
-    return this.getValue(parent, context);
+  describe() {
+    return {
+      type: 'ref',
+      key: this.key,
+    };
   }
 
-  getValue(parent, context) {
-    let isContext = this.isContext;
-    let value = this._get(isContext ? context : parent || context || {});
-    return this.map(value);
+  toString() {
+    return `Ref(${this.key})`;
+  }
+
+  static isRef(value) {
+    return value && value.__isYupRef;
   }
 }
 

src/mixed.js

@@ -134,11 +134,10 @@ const proto = (SchemaType.prototype = {
     return !this._typeCheck || this._typeCheck(v);
   },
 
-  resolve({ context, parent }) {
+  resolve(options) {
     if (this._conditions.length) {
       return this._conditions.reduce(
-        (schema, match) =>
-          match.resolve(schema, match.getValue(parent, context)),
+        (schema, condition) => condition.resolve(schema, options),
         this,
       );
     }
@@ -147,7 +146,7 @@ const proto = (SchemaType.prototype = {
   },
 
   cast(value, options = {}) {
-    let resolvedSchema = this.resolve(options);
+    let resolvedSchema = this.resolve({ ...options, value });
     let result = resolvedSchema._cast(value, options);
 
     if (
@@ -240,12 +239,12 @@ const proto = (SchemaType.prototype = {
   },
 
   validate(value, options = {}) {
-    let schema = this.resolve(options);
+    let schema = this.resolve({ ...options, value });
     return schema._validate(value, options);
   },
 
   validateSync(value, options = {}) {
-    let schema = this.resolve(options);
+    let schema = this.resolve({ ...options, value });
     let result, err;
 
     schema
@@ -268,7 +267,7 @@ const proto = (SchemaType.prototype = {
 
   isValidSync(value, options) {
     try {
-      this.validateSync(value, { ...options });
+      this.validateSync(value, options);
       return true;
     } catch (err) {
       if (err.name === 'ValidationError') return false;
@@ -380,11 +379,16 @@ const proto = (SchemaType.prototype = {
   },
 
   when(keys, options) {
+    if (arguments.length === 1) {
+      options = keys;
+      keys = '.';
+    }
+
     var next = this.clone(),
       deps = [].concat(keys).map(key => new Ref(key));
 
     deps.forEach(dep => {
-      if (!dep.isContext) next._deps.push(dep.key);
+      if (dep.isSibling) next._deps.push(dep.key);
     });
 
     next._conditions.push(new Condition(deps, options));

src/util/createValidation.js

@@ -68,8 +68,10 @@ export default function createValidation(options) {
     ...rest
   }) {
     let parent = options.parent;
-    let resolve = value =>
-      Ref.isRef(value) ? value.getValue(parent, options.context) : value;
+    let resolve = item =>
+      Ref.isRef(item)
+        ? item.getValue({ value, parent, context: options.context })
+        : item;
 
     let createError = createErrorFactory({
       message,

src/util/sortFields.js

@@ -23,7 +23,7 @@ export default function sortFields(fields, excludes = []) {
 
       if (!~nodes.indexOf(key)) nodes.push(key);
 
-      if (Ref.isRef(value) && !value.isContext) addNode(value.path, key);
+      if (Ref.isRef(value) && value.isSibling) addNode(value.path, key);
       else if (isSchema(value) && value._deps)
         value._deps.forEach(path => addNode(path, key));
     }

test/mixed.js

@@ -656,7 +656,7 @@ describe('Mixed Types ', () => {
 
   it('should handle multiple conditionals', function() {
     let called = false;
-    let inst = mixed().when(['prop', 'other'], function(prop, other) {
+    let inst = mixed().when(['$prop', '$other'], function(prop, other) {
       other.should.equal(true);
       prop.should.equal(1);
       called = true;
@@ -665,7 +665,7 @@ describe('Mixed Types ', () => {
     inst.cast({}, { context: { prop: 1, other: true } });
     called.should.equal(true);
 
-    inst = mixed().when(['prop', 'other'], {
+    inst = mixed().when(['$prop', '$other'], {
       is: 5,
       then: mixed().required(),
     });
@@ -720,6 +720,36 @@ describe('Mixed Types ', () => {
     inst.default().should.eql({ prop: undefined });
   });
 
+  it('should support self references in conditions', async function() {
+    let inst = number().when('.', {
+      is: value => value > 0,
+      then: number().min(5),
+    });
+
+    await inst
+      .validate(4)
+      .should.be.rejectedWith(ValidationError, /must be greater/);
+
+    await inst.validate(5).should.be.fulfilled();
+
+    await inst.validate(-1).should.be.fulfilled();
+  });
+
+  it('should support conditional single argument as options shortcut', async function() {
+    let inst = number().when({
+      is: value => value > 0,
+      then: number().min(5),
+    });
+
+    await inst
+      .validate(4)
+      .should.be.rejectedWith(ValidationError, /must be greater/);
+
+    await inst.validate(5).should.be.fulfilled();
+
+    await inst.validate(-1).should.be.fulfilled();
+  });
+
   it('should use label in error message', async function() {
     let label = 'Label';
     let inst = object({