fix(zone.js): Promise.resolve(subPromise) should return subPromise (#53423)

JiaLiPassion · alxhub · commit 08b0c87a9480 · 2023-12-11T10:55:12.000-08:00
In the original `Promise` impelmentation, zone.js follow the spec from https://promisesaplus.com/#point-51. ``` const p1 = Promise.resolve(1); const p2 = Promise.resolve(p1); p1 === p2; // false ``` in this case, `p2` should be the same status with `p1` but they are still different instances. And for some edge case. ``` class MyPromise extends Promise { constructor(sub) { super((res) => res(null)); this.sub = sub; } then(onFufilled, onRejected) { this.sub.then(onFufilled, onRejected); } } const p1 = new Promise(setTimeout(res), 100); const myP = new MyPromise(p1); const r = await myP; r === 1; // false ``` So in the above code, `myP` is not the same instance with `p1`, and since `myP` is resolved in constructor, so `await myP` will just pass without waiting for `p1`. And in the current `tc39` spec here https://tc39.es/ecma262/multipage/control-abstraction-objects.html#sec-promise-resolve `Promise.resolve(subP)` should return `subP`. ``` const p1 = Promise.resolve(1); const p2 = Promise.resolve(p1); p1 === p2; // true ``` So the above `MyPromise` can wait for the `p1` correctly. PR Close #53423
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -234,7 +234,6 @@ jobs:
         # Install
       - run: yarn --cwd packages/zone.js install --frozen-lockfile --non-interactive
         # Run zone.js tools tests
-      - run: yarn --cwd packages/zone.js promisetest
       - run: yarn --cwd packages/zone.js promisefinallytest
       - run: yarn --cwd packages/zone.js jest:test
       - run: yarn --cwd packages/zone.js jest:nodetest
diff --git a/packages/zone.js/README.md b/packages/zone.js/README.md
@@ -134,8 +134,5 @@ import 'zone.js/plugins/zone-patch-canvas';
 |`zone-patch-user-media.js`|patch for `UserMedia API`|
 |`zone-patch-message-port.js`|patch for `MessagePort API`|
 
-## Promise A+ test passed
-[![Promises/A+ 1.1 compliant](https://promisesaplus.com/assets/logo-small.png)](https://promisesaplus.com/)
-
 ## License
 MIT
diff --git a/packages/zone.js/lib/common/promise.ts b/packages/zone.js/lib/common/promise.ts
@@ -292,6 +292,9 @@ Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePr
     }
 
     static resolve<R>(value: R): Promise<R> {
+      if (value instanceof ZoneAwarePromise) {
+        return value;
+      }
       return resolvePromise(<ZoneAwarePromise<R>>new this(null as any), RESOLVED, value);
     }
 
diff --git a/packages/zone.js/package.json b/packages/zone.js/package.json
@@ -19,15 +19,13 @@
     "jest-environment-jsdom": "^29.0.3",
     "jest-environment-node": "^29.0.3",
     "mocha": "^10.2.0",
-    "mock-require": "3.0.3",
-    "promises-aplus-tests": "^2.1.2"
+    "mock-require": "3.0.3"
   },
   "scripts": {
     "closuretest": "./scripts/closure/closure_compiler.sh",
     "electrontest": "cd test/extra && node electron.js",
     "jest:test": "jest --config ./test/jest/jest.config.js ./test/jest/jest.spec.js",
     "jest:nodetest": "jest --config ./test/jest/jest.node.config.js ./test/jest/jest.spec.js",
-    "promisetest": "node ./test/promise/promise-test.mjs",
     "promisefinallytest": "mocha ./test/promise/promise.finally.spec.mjs"
   },
   "repository": {
diff --git a/packages/zone.js/test/common/Promise.spec.ts b/packages/zone.js/test/common/Promise.spec.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {isNode, zoneSymbol} from '../../lib/common/utils';
+import {isNode} from '../../lib/common/utils';
 import {ifEnvSupports} from '../test-util';
 
 declare const global: any;
@@ -76,6 +76,12 @@ describe(
         expect(new Promise(() => null) instanceof Promise).toBe(true);
       });
 
+      it('Promise.resolve(subPromise) should equal to subPromise', () => {
+        const p1 = Promise.resolve(1);
+        const p2 = Promise.resolve(p1);
+        expect(p1).toBe(p2);
+      });
+
       xit('should ensure that Promise this is instanceof Promise', () => {
         expect(() => {
           Promise.call({} as any, () => null);
@@ -130,6 +136,23 @@ describe(
         expect(new MyPromise(() => {}).then(() => null) instanceof MyPromise).toBe(true);
       });
 
+      it('should allow subclassing with own then', (done: DoneFn) => {
+        class MyPromise extends Promise<any> {
+          constructor(private sub: Promise<any>) {
+            super((resolve) => {resolve(null)});
+          }
+
+          override then(onFulfilled: any, onRejected: any) {
+            return this.sub.then(onFulfilled, onRejected);
+          }
+        }
+        const p = Promise.resolve(1);
+        new MyPromise(p).then((v: any) => {
+          expect(v).toBe(1);
+          done();
+        }, () => done());
+      });
+
       it('Symbol.species should return ZoneAwarePromise', () => {
         const empty = function() {};
         const promise = Promise.resolve(1);
diff --git a/packages/zone.js/test/promise/promise-test.mjs b/packages/zone.js/test/promise/promise-test.mjs
diff --git a/packages/zone.js/yarn.lock b/packages/zone.js/yarn.lock

Original file line number	Diff line number	Diff line change
`@@ -292,6 +292,9 @@ Zone.__load_patch('ZoneAwarePromise', (global: any, Zone: ZoneType, api: _ZonePr`
`292`	`292`	`}`
`293`	`293`
`294`	`294`	`static resolve<R>(value: R): Promise<R> {`
	`295`	`+ if (value instanceof ZoneAwarePromise) {`
	`296`	`+ return value;`
	`297`	`+ }`
`295`	`298`	`return resolvePromise(<ZoneAwarePromise<R>>new this(null as any), RESOLVED, value);`
`296`	`299`	`}`
`297`	`300`