fix(forms): remove equalsTo validator (#15050)

This API was introduced only in a beta release, and is being removed because we found it to be incorrect prior to launch. For more information about why this is being removed, see https://github.com/angular/angular/pull/15050.

packages/forms/src/validators.ts

@@ -59,30 +59,6 @@ const EMAIL_REGEXP =
  * @stable
  */
 export class Validators {
-  /**
-   * Validator that compares the value of the given FormControls
-   */
-  static equalsTo(...fieldPaths: string[]): ValidatorFn {
-    return function(control: FormControl): {[key: string]: any} {
-      if (fieldPaths.length < 1) {
-        throw new Error('You must compare to at least 1 other field');
-      }
-
-      for (let fieldName of fieldPaths) {
-        let field = (<FormGroup>control.parent).get(fieldName);
-        if (!field) {
-          throw new Error(
-              `Field: ${fieldName} undefined, are you sure that ${fieldName} exists in the group`);
-        }
-
-        if (field.value !== control.value) {
-          return {'equalsTo': {'unequalField': fieldName}};
-        }
-      }
-      return null;
-    };
-  }
-
   /**
    * Validator that requires controls to have a non-empty value.
    */

packages/forms/test/validators_spec.ts

@@ -38,44 +38,6 @@ export function main() {
   }
 
   describe('Validators', () => {
-    describe('equalsTo', () => {
-      it('should not error when equal', () => {
-        let group = new FormGroup({f1: new FormControl('a'), f2: new FormControl('a')});
-        let validator = Validators.equalsTo('f2');
-        expect(validator(group.controls['f1'])).toBeNull();
-      });
-
-      it('should error when not equal', () => {
-        let group = new FormGroup({f1: new FormControl('a'), f2: new FormControl('b')});
-        let validator = Validators.equalsTo('f2');
-        expect(validator(group.controls['f1'])).toEqual({equalsTo: {unequalField: 'f2'}});
-      });
-
-      it('should throw if passed a form control', () => {
-        let validator = Validators.equalsTo('f1', 'f2');
-        // cast it to any so we don't get TS errors
-        expect(() => validator(<any>new FormGroup({f1: new FormControl('')}))).toThrow();
-      });
-
-      it('should throw if passed a form array', () => {
-        let validator = Validators.equalsTo('f1', 'f2');
-        // cast it to any so we don't get TS errors
-        expect(() => validator(<any>new FormArray([]))).toThrow();
-      });
-
-      it('should throw if not passed any field to compare', () => {
-        let validator = Validators.equalsTo();
-        expect(() => validator(new FormControl('a'))).toThrow();
-      });
-
-      it('should throw if field passed does not exist in the group', () => {
-        let group = new FormGroup({f1: new FormControl('a'), f2: new FormControl('b')});
-        let validator = Validators.equalsTo('f3', 'f4');
-        // cast it to any so we don't get TS errors
-        expect(() => validator(new FormControl('a'))).toThrow();
-      });
-    });
-
     describe('required', () => {
       it('should error on an empty string',
          () => { expect(Validators.required(new FormControl(''))).toEqual({'required': true}); });

tools/public_api_guard/forms/typings/forms.d.ts

@@ -554,7 +554,6 @@ export declare class Validators {
     static email(control: AbstractControl): {
         [key: string]: boolean;
     };
-    static equalsTo(...fieldPaths: string[]): ValidatorFn;
     static maxLength(maxLength: number): ValidatorFn;
     static minLength(minLength: number): ValidatorFn;
     static nullValidator(c: AbstractControl): {