feat(compiler): introduce TestBed.overrideTemplateUsingTestingModule

This allows to overwrite templates for JIT and AOT components alike.

In contrast to `TestBed.overrideTemplate`, the template is compiled
in the context of the testing module, allowing to use other testing
directives.

Closes #19815

packages/core/src/core_private_export.ts

@@ -20,5 +20,5 @@ export {DirectRenderer as ɵDirectRenderer, RenderDebugInfo as ɵRenderDebugInfo
 export {global as ɵglobal, looseIdentical as ɵlooseIdentical, stringify as ɵstringify} from './util';
 export {makeDecorator as ɵmakeDecorator} from './util/decorators';
 export {isObservable as ɵisObservable, isPromise as ɵisPromise} from './util/lang';
-export {clearProviderOverrides as ɵclearProviderOverrides, overrideProvider as ɵoverrideProvider} from './view/index';
+export {clearOverrides as ɵclearOverrides, overrideComponentView as ɵoverrideComponentView, overrideProvider as ɵoverrideProvider} from './view/index';
 export {NOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR as ɵNOT_FOUND_CHECK_ONLY_ELEMENT_INJECTOR} from './view/provider';

packages/core/src/view/entrypoint.ts

@@ -7,11 +7,12 @@
  */
 
 import {Injector} from '../di/injector';
+import {ComponentFactory} from '../linker/component_factory';
 import {NgModuleFactory, NgModuleRef} from '../linker/ng_module_factory';
 import {Type} from '../type';
 
 import {initServicesIfNeeded} from './services';
-import {NgModuleDefinitionFactory, ProviderOverride, Services} from './types';
+import {NgModuleDefinitionFactory, ProviderOverride, Services, ViewDefinition} from './types';
 import {resolveDefinition} from './util';
 
 export function overrideProvider(override: ProviderOverride) {
@@ -19,9 +20,14 @@ export function overrideProvider(override: ProviderOverride) {
   return Services.overrideProvider(override);
 }
 
-export function clearProviderOverrides() {
+export function overrideComponentView(comp: Type<any>, componentFactory: ComponentFactory<any>) {
   initServicesIfNeeded();
-  return Services.clearProviderOverrides();
+  return Services.overrideComponentView(comp, componentFactory);
+}
+
+export function clearOverrides() {
+  initServicesIfNeeded();
+  return Services.clearOverrides();
 }
 
 // Attention: this function is called as top level function.

packages/core/src/view/index.ts

@@ -7,7 +7,7 @@
  */
 
 export {anchorDef, elementDef} from './element';
-export {clearProviderOverrides, createNgModuleFactory, overrideProvider} from './entrypoint';
+export {clearOverrides, createNgModuleFactory, overrideComponentView, overrideProvider} from './entrypoint';
 export {ngContentDef} from './ng_content';
 export {moduleDef, moduleProvideDef} from './ng_module';
 export {directiveDef, pipeDef, providerDef} from './provider';

packages/core/src/view/services.ts

@@ -10,6 +10,7 @@ import {isDevMode} from '../application_ref';
 import {DebugElement, DebugNode, EventListener, getDebugNode, indexDebugNode, removeDebugNodeFromIndex} from '../debug/debug_node';
 import {Injector} from '../di';
 import {ErrorHandler} from '../error_handler';
+import {ComponentFactory} from '../linker/component_factory';
 import {NgModuleRef} from '../linker/ng_module_factory';
 import {Renderer2, RendererFactory2, RendererStyleFlags2, RendererType2} from '../render/api';
 import {Sanitizer} from '../security';
@@ -18,9 +19,9 @@ import {Type} from '../type';
 import {isViewDebugError, viewDestroyedError, viewWrappedDebugError} from './errors';
 import {resolveDep} from './provider';
 import {dirtyParentQueries, getQueryValue} from './query';
-import {createInjector, createNgModuleRef} from './refs';
+import {createInjector, createNgModuleRef, getComponentViewDefinitionFactory} from './refs';
 import {ArgumentType, BindingFlags, CheckType, DebugContext, DepDef, ElementData, NgModuleDefinition, NgModuleProviderDef, NodeDef, NodeFlags, NodeLogger, ProviderOverride, RootData, Services, ViewData, ViewDefinition, ViewState, asElementData, asPureExpressionData} from './types';
-import {NOOP, isComponentView, renderNode, splitDepsDsl, viewParentEl} from './util';
+import {NOOP, isComponentView, renderNode, resolveDefinition, splitDepsDsl, viewParentEl} from './util';
 import {checkAndUpdateNode, checkAndUpdateView, checkNoChangesNode, checkNoChangesView, createComponentView, createEmbeddedView, createRootView, destroyView} from './view';
 
 
@@ -38,7 +39,8 @@ export function initServicesIfNeeded() {
   Services.createComponentView = services.createComponentView;
   Services.createNgModuleRef = services.createNgModuleRef;
   Services.overrideProvider = services.overrideProvider;
-  Services.clearProviderOverrides = services.clearProviderOverrides;
+  Services.overrideComponentView = services.overrideComponentView;
+  Services.clearOverrides = services.clearOverrides;
   Services.checkAndUpdateView = services.checkAndUpdateView;
   Services.checkNoChangesView = services.checkNoChangesView;
   Services.destroyView = services.destroyView;
@@ -58,7 +60,8 @@ function createProdServices() {
     createComponentView: createComponentView,
     createNgModuleRef: createNgModuleRef,
     overrideProvider: NOOP,
-    clearProviderOverrides: NOOP,
+    overrideComponentView: NOOP,
+    clearOverrides: NOOP,
     checkAndUpdateView: checkAndUpdateView,
     checkNoChangesView: checkNoChangesView,
     destroyView: destroyView,
@@ -84,7 +87,8 @@ function createDebugServices() {
     createComponentView: debugCreateComponentView,
     createNgModuleRef: debugCreateNgModuleRef,
     overrideProvider: debugOverrideProvider,
-    clearProviderOverrides: debugClearProviderOverrides,
+    overrideComponentView: debugOverrideComponentView,
+    clearOverrides: debugClearOverrides,
     checkAndUpdateView: debugCheckAndUpdateView,
     checkNoChangesView: debugCheckNoChangesView,
     destroyView: debugDestroyView,
@@ -139,10 +143,15 @@ function debugCreateEmbeddedView(
 
 function debugCreateComponentView(
     parentView: ViewData, nodeDef: NodeDef, viewDef: ViewDefinition, hostElement: any): ViewData {
-  const defWithOverride = applyProviderOverridesToView(viewDef);
+  const overrideComponentView =
+      viewDefOverrides.get(nodeDef.element !.componentProvider !.provider !.token);
+  if (overrideComponentView) {
+    viewDef = overrideComponentView;
+  } else {
+    viewDef = applyProviderOverridesToView(viewDef);
+  }
   return callWithDebugContext(
-      DebugAction.create, createComponentView, null,
-      [parentView, nodeDef, defWithOverride, hostElement]);
+      DebugAction.create, createComponentView, null, [parentView, nodeDef, viewDef, hostElement]);
 }
 
 function debugCreateNgModuleRef(
@@ -153,13 +162,21 @@ function debugCreateNgModuleRef(
 }
 
 const providerOverrides = new Map<any, ProviderOverride>();
+const viewDefOverrides = new Map<any, ViewDefinition>();
 
 function debugOverrideProvider(override: ProviderOverride) {
   providerOverrides.set(override.token, override);
 }
 
-function debugClearProviderOverrides() {
+function debugOverrideComponentView(comp: any, compFactory: ComponentFactory<any>) {
+  const hostViewDef = resolveDefinition(getComponentViewDefinitionFactory(compFactory));
+  const compViewDef = resolveDefinition(hostViewDef.nodes[0].element !.componentView !);
+  viewDefOverrides.set(comp, compViewDef);
+}
+
+function debugClearOverrides() {
   providerOverrides.clear();
+  viewDefOverrides.clear();
 }
 
 // Notes about the algorithm:

packages/core/src/view/types.ts

@@ -8,6 +8,7 @@
 
 import {Injector} from '../di';
 import {ErrorHandler} from '../error_handler';
+import {ComponentFactory} from '../linker/component_factory';
 import {NgModuleRef} from '../linker/ng_module_factory';
 import {QueryList} from '../linker/query_list';
 import {TemplateRef} from '../linker/template_ref';
@@ -16,6 +17,7 @@ import {Renderer2, RendererFactory2, RendererType2} from '../render/api';
 import {Sanitizer, SecurityContext} from '../security';
 import {Type} from '../type';
 
+
 // -------------------------------------
 // Defs
 // -------------------------------------
@@ -522,7 +524,8 @@ export interface Services {
       moduleType: Type<any>, parent: Injector, bootstrapComponents: Type<any>[],
       def: NgModuleDefinition): NgModuleRef<any>;
   overrideProvider(override: ProviderOverride): void;
-  clearProviderOverrides(): void;
+  overrideComponentView(compType: Type<any>, compFactory: ComponentFactory<any>): void;
+  clearOverrides(): void;
   checkAndUpdateView(view: ViewData): void;
   checkNoChangesView(view: ViewData): void;
   destroyView(view: ViewData): void;
@@ -547,7 +550,8 @@ export const Services: Services = {
   createComponentView: undefined !,
   createNgModuleRef: undefined !,
   overrideProvider: undefined !,
-  clearProviderOverrides: undefined !,
+  overrideComponentView: undefined !,
+  clearOverrides: undefined !,
   checkAndUpdateView: undefined !,
   checkNoChangesView: undefined !,
   destroyView: undefined !,