feat(forms): multiple validators for array method (#20766)

Change array method signature so that array of validator and/or async
validatior functions can be passed.

Fixes #20665

PR Close #20766

packages/forms/test/form_builder_spec.ts

@@ -5,9 +5,10 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-
+import {fakeAsync, tick} from '@angular/core/testing';
 import {beforeEach, describe, expect, it} from '@angular/core/testing/src/testing_internal';
 import {FormBuilder} from '@angular/forms';
+import {of } from 'rxjs/observable/of';
 
 (function() {
   function syncValidator(_: any /** TODO #9100 */): any /** TODO #9100 */ { return null; }
@@ -97,5 +98,26 @@ import {FormBuilder} from '@angular/forms';
       expect(a.validator).toBe(syncValidator);
       expect(a.asyncValidator).toBe(asyncValidator);
     });
+
+    it('should create control arrays with multiple async validators', fakeAsync(() => {
+         function asyncValidator1() { return of ({'async1': true}); }
+         function asyncValidator2() { return of ({'async2': true}); }
+
+         const a = b.array(['one', 'two'], null, [asyncValidator1, asyncValidator2]);
+         expect(a.value).toEqual(['one', 'two']);
+
+         tick();
+
+         expect(a.errors).toEqual({'async1': true, 'async2': true});
+       }));
+
+    it('should create control arrays with multiple sync validators', () => {
+      function syncValidator1() { return {'sync1': true}; }
+      function syncValidator2() { return {'sync2': true}; }
+
+      const a = b.array(['one', 'two'], [syncValidator1, syncValidator2]);
+      expect(a.value).toEqual(['one', 'two']);
+      expect(a.errors).toEqual({'sync1': true, 'sync2': true});
+    });
   });
 })();