fix: String.split(str, n) stops after n separator (#10408)

modules/@angular/compiler/test/util_spec.ts

@@ -9,7 +9,7 @@
 import {fakeAsync} from '@angular/core/testing/fake_async';
 import {beforeEach, beforeEachProviders, ddescribe, describe, expect, iit, inject, it, xit} from '@angular/core/testing/testing_internal';
 
-import {SyncAsyncResult} from '../src/util';
+import {SyncAsyncResult, splitAtColon} from '../src/util';
 
 export function main() {
   describe('util', () => {
@@ -20,5 +20,21 @@ export function main() {
            sar.asyncResult.then((v: any) => expect(v).toBe(syncValue));
          }));
     });
+
+    describe('splitAtColon', () => {
+      it('should split when a single ":" is present', () => {
+        expect(splitAtColon('a:b', [])).toEqual(['a', 'b']);
+      });
+
+      it('should trim parts', () => { expect(splitAtColon(' a : b ', [])).toEqual(['a', 'b']); });
+
+      it('should support multiple ":"', () => {
+        expect(splitAtColon('a:b:c', [])).toEqual(['a', 'b:c']);
+      });
+
+      it('should use the default value when no ":" is present', () => {
+        expect(splitAtColon('ab', ['c', 'd'])).toEqual(['c', 'd']);
+      });
+    });
   });
 }