feat: tree-shakeable providers API updates (#22655)

Rename @Injectable({scope -> providedIn}).

Instead of {providedIn: APP_ROOT_SCOPE}, accept {providedIn: 'root'}.
Also, {providedIn: null} implies the injectable should not be added
to any scope.

PR Close #22655

packages/compiler-cli/integrationtest/bazel/injectable_def/app/test/BUILD.bazel

@@ -14,6 +14,7 @@ ts_library(
     deps = [
         "//packages/compiler-cli/integrationtest/bazel/injectable_def/app",
         "//packages/core",
+        "//packages/core/testing",
         "//packages/platform-server",
     ],
 )

packages/compiler-cli/integrationtest/bazel/injectable_def/app/test/app_spec.ts

@@ -6,7 +6,8 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {enableProdMode} from '@angular/core';
+import {Component, Injectable, NgModule} from '@angular/core';
+import {TestBed} from '@angular/core/testing';
 import {renderModuleFactory} from '@angular/platform-server';
 import {BasicAppModuleNgFactory} from 'app_built/src/basic.ngfactory';
 import {DepAppModuleNgFactory} from 'app_built/src/dep.ngfactory';
@@ -16,8 +17,6 @@ import {SelfAppModuleNgFactory} from 'app_built/src/self.ngfactory';
 import {StringAppModuleNgFactory} from 'app_built/src/string.ngfactory';
 import {TokenAppModuleNgFactory} from 'app_built/src/token.ngfactory';
 
-enableProdMode();
-
 describe('ngInjectableDef Bazel Integration', () => {
   it('works in AOT', done => {
     renderModuleFactory(BasicAppModuleNgFactory, {
@@ -88,4 +87,41 @@ describe('ngInjectableDef Bazel Integration', () => {
       done();
     });
   });
+
+  it('allows provider override in JIT for root-scoped @Injectables', () => {
+    @Injectable({
+      providedIn: 'root',
+      useValue: new Service('default'),
+    })
+    class Service {
+      constructor(readonly value: string) {}
+    }
+
+    TestBed.configureTestingModule({});
+    TestBed.overrideProvider(Service, {useValue: new Service('overridden')});
+
+    expect(TestBed.get(Service).value).toEqual('overridden');
+  });
+
+  it('allows provider override in JIT for module-scoped @Injectables', () => {
+
+    @NgModule()
+    class Module {
+    }
+
+    @Injectable({
+      providedIn: Module,
+      useValue: new Service('default'),
+    })
+    class Service {
+      constructor(readonly value: string) {}
+    }
+
+    TestBed.configureTestingModule({
+      imports: [Module],
+    });
+    TestBed.overrideProvider(Service, {useValue: new Service('overridden')});
+
+    expect(TestBed.get(Service).value).toEqual('overridden');
+  });
 });