fix(zone.js): patch nodejs EventEmtter.prototype.off (#37863)

JiaLiPassion · mhevery · commit 1822cbcd4665 · 2020-07-24T15:45:00.000-07:00
Close #35473 zone.js nodejs patch should also patch `EventEmitter.prototype.off` as `removeListener`. So `off` can correctly remove the listeners added by `EventEmitter.prototype.addListener` PR Close #37863
diff --git a/packages/zone.js/lib/node/events.ts b/packages/zone.js/lib/node/events.ts
@@ -16,6 +16,7 @@ Zone.__load_patch('EventEmitter', (global: any) => {
   const EE_REMOVE_ALL_LISTENER = 'removeAllListeners';
   const EE_LISTENERS = 'listeners';
   const EE_ON = 'on';
+  const EE_OFF = 'off';
 
   const compareTaskCallbackVsDelegate = function(task: any, delegate: any) {
     // same callback, same capture, same event name, just return
@@ -47,6 +48,7 @@ Zone.__load_patch('EventEmitter', (global: any) => {
     });
     if (result && result[0]) {
       obj[EE_ON] = obj[EE_ADD_LISTENER];
+      obj[EE_OFF] = obj[EE_REMOVE_LISTENER];
     }
   }
 
diff --git a/packages/zone.js/test/node/events.spec.ts b/packages/zone.js/test/node/events.spec.ts
@@ -66,6 +66,18 @@ describe('nodejs EventEmitter', () => {
       emitter.emit('test2', 'test value');
     });
   });
+  it('should remove listeners by calling off properly', () => {
+    zoneA.run(() => {
+      emitter.on('test', shouldNotRun);
+      emitter.on('test2', shouldNotRun);
+      emitter.off('test', shouldNotRun);
+    });
+    zoneB.run(() => {
+      emitter.off('test2', shouldNotRun);
+      emitter.emit('test', 'test value');
+      emitter.emit('test2', 'test value');
+    });
+  });
   it('remove listener should return event emitter', () => {
     zoneA.run(() => {
       emitter.on('test', shouldNotRun);

Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,7 @@ Zone.__load_patch('EventEmitter', (global: any) => {`
`16`	`16`	`const EE_REMOVE_ALL_LISTENER = 'removeAllListeners';`
`17`	`17`	`const EE_LISTENERS = 'listeners';`
`18`	`18`	`const EE_ON = 'on';`
	`19`	`+ const EE_OFF = 'off';`
`19`	`20`
`20`	`21`	`const compareTaskCallbackVsDelegate = function(task: any, delegate: any) {`
`21`	`22`	`// same callback, same capture, same event name, just return`
`@@ -47,6 +48,7 @@ Zone.__load_patch('EventEmitter', (global: any) => {`
`47`	`48`	`});`
`48`	`49`	`if (result && result[0]) {`
`49`	`50`	`obj[EE_ON] = obj[EE_ADD_LISTENER];`
	`51`	`+ obj[EE_OFF] = obj[EE_REMOVE_LISTENER];`
`50`	`52`	`}`
`51`	`53`	`}`
`52`	`54`