refactor(core): extract `DoBootstrap` to separate file. (#39621)

Extract `DoBootstrap` interface to a separate file to break circular dependency.

PR Close #39621

packages/core/src/metadata.ts

@@ -11,17 +11,12 @@
  * to be used by the decorator versions of these annotations.
  */
 
-import {Attribute} from './di';
-import {ContentChild, ContentChildren, Query, ViewChild, ViewChildren} from './metadata/di';
-import {Component, Directive, HostBinding, HostListener, Input, Output, Pipe} from './metadata/directives';
-import {DoBootstrap, ModuleWithProviders, NgModule} from './metadata/ng_module';
-import {SchemaMetadata} from './metadata/schema';
-import {ViewEncapsulation} from './metadata/view';
 
 export {Attribute} from './di';
 export {AfterContentChecked, AfterContentInit, AfterViewChecked, AfterViewInit, DoCheck, OnChanges, OnDestroy, OnInit} from './interface/lifecycle_hooks';
 export {ANALYZE_FOR_ENTRY_COMPONENTS, ContentChild, ContentChildDecorator, ContentChildren, ContentChildrenDecorator, Query, ViewChild, ViewChildDecorator, ViewChildren, ViewChildrenDecorator} from './metadata/di';
 export {Component, ComponentDecorator, Directive, DirectiveDecorator, HostBinding, HostBindingDecorator, HostListener, HostListenerDecorator, Input, InputDecorator, Output, OutputDecorator, Pipe, PipeDecorator} from './metadata/directives';
-export {DoBootstrap, ModuleWithProviders, NgModule, NgModuleDecorator} from './metadata/ng_module';
+export {DoBootstrap} from './metadata/do_boostrap';
+export {ModuleWithProviders, NgModule, NgModuleDecorator} from './metadata/ng_module';
 export {CUSTOM_ELEMENTS_SCHEMA, NO_ERRORS_SCHEMA, SchemaMetadata} from './metadata/schema';
 export {ViewEncapsulation} from './metadata/view';

packages/core/src/metadata/do_boostrap.ts

@@ -0,0 +1,34 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {ApplicationRef} from '../application_ref';
+
+
+/**
+ * @description
+ * Hook for manual bootstrapping of the application instead of using bootstrap array in @NgModule
+ * annotation.
+ *
+ * Reference to the current application is provided as a parameter.
+ *
+ * See ["Bootstrapping"](guide/bootstrapping) and ["Entry components"](guide/entry-components).
+ *
+ * @usageNotes
+ * ```typescript
+ * class AppModule implements DoBootstrap {
+ *   ngDoBootstrap(appRef: ApplicationRef) {
+ *     appRef.bootstrap(AppComponent); // Or some other component
+ *   }
+ * }
+ * ```
+ *
+ * @publicApi
+ */
+export interface DoBootstrap {
+  ngDoBootstrap(appRef: ApplicationRef): void;
+}

packages/core/src/metadata/ng_module.ts

@@ -6,7 +6,6 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ApplicationRef} from '../application_ref';
 import {InjectorType, ɵɵdefineInjector} from '../di/interface/defs';
 import {Provider} from '../di/interface/provider';
 import {convertInjectableProviderToFactory} from '../di/util';
@@ -321,29 +320,6 @@ export const NgModule: NgModuleDecorator = makeDecorator(
      */
     (type: Type<any>, meta: NgModule) => SWITCH_COMPILE_NGMODULE(type, meta));
 
-/**
- * @description
- * Hook for manual bootstrapping of the application instead of using bootstrap array in @NgModule
- * annotation.
- *
- * Reference to the current application is provided as a parameter.
- *
- * See ["Bootstrapping"](guide/bootstrapping) and ["Entry components"](guide/entry-components).
- *
- * @usageNotes
- * ```typescript
- * class AppModule implements DoBootstrap {
- *   ngDoBootstrap(appRef: ApplicationRef) {
- *     appRef.bootstrap(AppComponent); // Or some other component
- *   }
- * }
- * ```
- *
- * @publicApi
- */
-export interface DoBootstrap {
-  ngDoBootstrap(appRef: ApplicationRef): void;
-}
 
 function preR3NgModuleCompile(moduleType: Type<any>, metadata?: NgModule): void {
   let imports = (metadata && metadata.imports) || [];