Revert "refactor(core): allow multiple DI profilers (angular#60562)" (angular#60611)

This reverts commit b21c6e5.

PR Close angular#60611

Author: thePunderWoman

packages/core/src/render3/debug/injector_profiler.ts

@@ -194,55 +194,33 @@ export function setInjectorProfilerContext(context: InjectorProfilerContext) {
   return previous;
 }
 
-const injectorProfilerCallbacks: InjectorProfiler[] = [];
-
-const NOOP_PROFILER_REMOVAL = () => {};
-
-function removeProfiler(profiler: InjectorProfiler) {
-  const profilerIdx = injectorProfilerCallbacks.indexOf(profiler);
-  if (profilerIdx !== -1) {
-    injectorProfilerCallbacks.splice(profilerIdx, 1);
-  }
-}
+let injectorProfilerCallback: InjectorProfiler | null = null;
 
 /**
- * Adds a callback function which will be invoked during certain DI events within the
- * runtime (for example: injecting services, creating injectable instances, configuring providers).
- * Multiple profiler callbacks can be set: in this case profiling events are
- * reported to every registered callback.
+ * Sets the callback function which will be invoked during certain DI events within the
+ * runtime (for example: injecting services, creating injectable instances, configuring providers)
  *
  * Warning: this function is *INTERNAL* and should not be relied upon in application's code.
  * The contract of the function might be changed in any release and/or the function can be removed
  * completely.
  *
  * @param profiler function provided by the caller or null value to disable profiling.
- * @returns a cleanup function that, when invoked, removes a given profiler callback.
  */
-export function setInjectorProfiler(injectorProfiler: InjectorProfiler | null): () => void {
+export const setInjectorProfiler = (injectorProfiler: InjectorProfiler | null) => {
   !ngDevMode && throwError('setInjectorProfiler should never be called in production mode');
-
-  if (injectorProfiler !== null) {
-    if (!injectorProfilerCallbacks.includes(injectorProfiler)) {
-      injectorProfilerCallbacks.push(injectorProfiler);
-    }
-    return () => removeProfiler(injectorProfiler);
-  } else {
-    injectorProfilerCallbacks.length = 0;
-    return NOOP_PROFILER_REMOVAL;
-  }
-}
+  injectorProfilerCallback = injectorProfiler;
+};
 
 /**
  * Injector profiler function which emits on DI events executed by the runtime.
  *
  * @param event InjectorProfilerEvent corresponding to the DI event being emitted
  */
-export function injectorProfiler(event: InjectorProfilerEvent): void {
+function injectorProfiler(event: InjectorProfilerEvent): void {
   !ngDevMode && throwError('Injector profiler should never be called in production mode');
 
-  for (let i = 0; i < injectorProfilerCallbacks.length; i++) {
-    const injectorProfilerCallback = injectorProfilerCallbacks[i];
-    injectorProfilerCallback(event);
+  if (injectorProfilerCallback != null /* both `null` and `undefined` */) {
+    injectorProfilerCallback!(event);
   }
 }
 

packages/core/test/acceptance/injector_profiler_spec.ts

@@ -11,7 +11,6 @@ import {
   afterRender,
   ClassProvider,
   Component,
-  createEnvironmentInjector,
   Directive,
   ElementRef,
   inject,
@@ -44,8 +43,6 @@ import {
   InjectorProfilerEventType,
   ProviderConfiguredEvent,
   setInjectorProfiler,
-  injectorProfiler,
-  InjectorProfilerContext,
 } from '../../src/render3/debug/injector_profiler';
 import {getNodeInjectorLView, NodeInjector} from '../../src/render3/di';
 import {
@@ -106,7 +103,7 @@ describe('setProfiler', () => {
     });
   });
 
-  afterEach(() => setInjectorProfiler(null));
+  afterAll(() => setInjectorProfiler(null));
 
   it('should emit DI events when a component contains a provider and injects it', () => {
     class MyService {}
@@ -385,70 +382,6 @@ describe('setProfiler', () => {
   });
 });
 
-describe('profiler activation and removal', () => {
-  class SomeClass {}
-
-  const fakeContext: InjectorProfilerContext = {
-    injector: Injector.create({providers: []}),
-    token: SomeClass,
-  };
-
-  const fakeEvent: InjectorCreatedInstanceEvent = {
-    type: InjectorProfilerEventType.InstanceCreatedByInjector,
-    context: fakeContext,
-    instance: {value: new SomeClass()},
-  };
-
-  it('should allow adding and removing multiple profilers', () => {
-    const events: string[] = [];
-    const r1 = setInjectorProfiler((e) => events.push('P1: ' + e.type));
-    const r2 = setInjectorProfiler((e) => events.push('P2: ' + e.type));
-
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1', 'P2: 1']);
-
-    r1();
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1', 'P2: 1', 'P2: 1']);
-
-    r2();
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1', 'P2: 1', 'P2: 1']);
-  });
-
-  it('should not add / remove the same profiler twice', () => {
-    const events: string[] = [];
-    const p1 = (e: InjectorProfilerEvent) => events.push('P1: ' + e.type);
-    const r1 = setInjectorProfiler(p1);
-    const r2 = setInjectorProfiler(p1);
-
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1']);
-
-    r1();
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1']);
-
-    // subsequent removals should be noop
-    r1();
-    r2();
-  });
-
-  it('should clear all profilers when passing null', () => {
-    const events: string[] = [];
-    setInjectorProfiler((e) => events.push('P1: ' + e.type));
-    setInjectorProfiler((e) => events.push('P2: ' + e.type));
-
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1', 'P2: 1']);
-
-    // clear all profilers
-    setInjectorProfiler(null);
-    injectorProfiler(fakeEvent);
-    expect(events).toEqual(['P1: 1', 'P2: 1']);
-  });
-});
-
 describe('getInjectorMetadata', () => {
   it('should be able to determine injector type and name', fakeAsync(() => {
     class MyServiceA {}
@@ -554,7 +487,7 @@ describe('getInjectorMetadata', () => {
 
 describe('getInjectorProviders', () => {
   beforeEach(() => setupFrameworkInjectorProfiler());
-  afterEach(() => setInjectorProfiler(null));
+  afterAll(() => setInjectorProfiler(null));
 
   it('should be able to get the providers from a components injector', () => {
     class MyService {}
@@ -1020,7 +953,7 @@ describe('getInjectorProviders', () => {
 
 describe('getDependenciesFromInjectable', () => {
   beforeEach(() => setupFrameworkInjectorProfiler());
-  afterEach(() => setInjectorProfiler(null));
+  afterAll(() => setInjectorProfiler(null));
 
   it('should be able to determine which injector dependencies come from', fakeAsync(() => {
     class MyService {}
@@ -1311,7 +1244,7 @@ describe('getDependenciesFromInjectable', () => {
 
 describe('getInjectorResolutionPath', () => {
   beforeEach(() => setupFrameworkInjectorProfiler());
-  afterEach(() => setInjectorProfiler(null));
+  afterAll(() => setInjectorProfiler(null));
 
   it('should be able to inspect injector hierarchy structure', fakeAsync(() => {
     class MyServiceA {}