fix(core): use addCustomEqualityTester instead of overriding toEqual (#22983)

This propagates other custom equality testers added by users. Additionally, if
an Angular project is using jasmine 2.6+, it will allow Jasmine's custom object
differ to print out pretty test error messages.

fixes #22939

PR Close #22983

packages/core/test/testing_internal_spec.ts

@@ -21,6 +21,18 @@ class SpyTestObj extends SpyObject {
 
 {
   describe('testing', () => {
+    describe('should respect custom equality tester', () => {
+      beforeEach(() => {
+        const equalIfMarried =
+            (first: any, second: any) => { return first === 'kevin' && second === 'patricia'; };
+        jasmine.addCustomEqualityTester(equalIfMarried);
+      });
+
+      it('for positive test', () => { expect('kevin').toEqual('patricia'); });
+
+      it('for negative test', () => { expect('kevin').not.toEqual('kevin'); });
+    });
+
     describe('equality', () => {
       it('should structurally compare objects', () => {
         const expected = new TestObj(new TestObj({'one': [1, 2]}));

packages/platform-browser/testing/src/matchers.ts

@@ -112,29 +112,23 @@ export const expect: (actual: any) => NgMatchers = <any>_global.expect;
 };
 
 _global.beforeEach(function() {
-  jasmine.addMatchers({
-    // Custom handler for Map as Jasmine does not support it yet
-    toEqual: function(util) {
-      return {
-        compare: function(actual: any, expected: any) {
-          return {pass: util.equals(actual, expected, [compareMap])};
-        }
-      };
-
-      function compareMap(actual: any, expected: any): boolean {
+  // Custom handler for Map as we use Jasmine 2.4, and support for maps is not
+  // added until Jasmine 2.6.
+  jasmine.addCustomEqualityTester(function compareMap(actual: any, expected: any): boolean {
     if (actual instanceof Map) {
       let pass = actual.size === expected.size;
       if (pass) {
-            actual.forEach((v: any, k: any) => { pass = pass && util.equals(v, expected.get(k)); });
+        actual.forEach((v: any, k: any) => {
+          pass = pass && jasmine.matchersUtil.equals(v, expected.get(k));
+        });
       }
       return pass;
     } else {
       // TODO(misko): we should change the return, but jasmine.d.ts is not null safe
       return undefined !;
     }
-      }
-    },
-
+  });
+  jasmine.addMatchers({
     toBePromise: function() {
       return {
         compare: function(actual: any) {

packages/types.d.ts

@@ -25,3 +25,12 @@ declare namespace jasmine {
     toHaveProperties(obj: any): boolean;
   }
 }
+
+/**
+*Jasmine matching utilities. These are added in the a more recent version of
+*the Jasmine typedefs than what we are using:
+*https://github.com/DefinitelyTyped/DefinitelyTyped/pull/20771
+*/
+declare namespace jasmine {
+  const matchersUtil: MatchersUtil;
+}