refactor(@angular/ssr): remove singleton helpers

This commit removes the singleton helpers and instead exposes the
classes directly.

goldens/public-api/angular/ssr/index.api.md

@@ -5,17 +5,12 @@
 ```ts
 
 // @public
-export interface AngularServerAppManager {
+export class AngularAppEngine {
     getHeaders(request: Request): Readonly<Map<string, string>>;
     render(request: Request, requestContext?: unknown): Promise<Response | null>;
+    static ɵhooks: Hooks;
 }
 
-// @public
-export function destroyAngularAppEngine(): void;
-
-// @public
-export function getOrCreateAngularAppEngine(): AngularServerAppManager;
-
 // (No @packageDocumentation comment for this package)
 
 ```

goldens/public-api/angular/ssr/node/index.api.md

@@ -11,7 +11,7 @@ import { StaticProvider } from '@angular/core';
 import { Type } from '@angular/core';
 
 // @public
-export interface AngularNodeServerAppManager {
+export class AngularNodeAppEngine {
     getHeaders(request: IncomingMessage): Readonly<Map<string, string>>;
     render(request: IncomingMessage, requestContext?: unknown): Promise<Response | null>;
 }
@@ -46,12 +46,6 @@ export interface CommonEngineRenderOptions {
 // @public
 export function createWebRequestFromNodeRequest(nodeRequest: IncomingMessage): Request;
 
-// @public
-export function destroyAngularNodeAppEngine(): void;
-
-// @public
-export function getOrCreateAngularNodeAppEngine(): AngularNodeServerAppManager;
-
 // @public
 export function writeResponseToNodeResponse(source: Response, destination: ServerResponse): Promise<void>;
 

packages/angular/ssr/node/public_api.ts

@@ -12,11 +12,7 @@ export {
   type CommonEngineOptions,
 } from './src/common-engine/common-engine';
 
-export {
-  type AngularNodeServerAppManager,
-  destroyAngularNodeAppEngine,
-  getOrCreateAngularNodeAppEngine,
-} from './src/app-engine';
+export { AngularNodeAppEngine } from './src/app-engine';
 
 export { writeResponseToNodeResponse } from './src/response';
 export { createWebRequestFromNodeRequest } from './src/request';

packages/angular/ssr/node/src/app-engine.ts

@@ -6,17 +6,23 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { destroyAngularAppEngine, getOrCreateAngularAppEngine } from '@angular/ssr';
+import { AngularAppEngine } from '@angular/ssr';
 import type { IncomingMessage } from 'node:http';
 import { createWebRequestFromNodeRequest } from './request';
 
 /**
  * Angular server application engine.
- * Manages Angular server applications (including localized ones) and handles rendering requests.
-
+ * Manages Angular server applications (including localized ones), handles rendering requests,
+ * and optionally transforms index HTML before rendering.
+ *
+ * @note This class should be instantiated once and used as a singleton across the server-side
+ * application to ensure consistent handling of rendering requests and resource management.
+ *
  * @developerPreview
  */
-export interface AngularNodeServerAppManager {
+export class AngularNodeAppEngine {
+  private readonly angularAppEngine = new AngularAppEngine();
+
   /**
    * Renders an HTTP response based on the incoming request using the Angular server application.
    *
@@ -32,7 +38,9 @@ export interface AngularNodeServerAppManager {
    * @returns A promise that resolves to a `Response` object, or `null` if the request URL is for a static file
    * (e.g., `./logo.png`) rather than an application route.
    */
-  render(request: IncomingMessage, requestContext?: unknown): Promise<Response | null>;
+  render(request: IncomingMessage, requestContext?: unknown): Promise<Response | null> {
+    return this.angularAppEngine.render(createWebRequestFromNodeRequest(request), requestContext);
+  }
 
   /**
    * Retrieves HTTP headers for a request associated with statically generated (SSG) pages,
@@ -43,7 +51,7 @@ export interface AngularNodeServerAppManager {
    * @note This function should be used exclusively for retrieving headers of SSG pages.
    * @example
    * ```typescript
-   * const angularAppEngine = getOrCreateAngularNodeAppEngine();
+   * const angularAppEngine = new AngularNodeAppEngine();
    *
    * app.use(express.static('dist/browser', {
    *   setHeaders: (res, path) => {
@@ -58,51 +66,7 @@ export interface AngularNodeServerAppManager {
      }));
   * ```
   */
-  getHeaders(request: IncomingMessage): Readonly<Map<string, string>>;
-}
-
-/**
- * Angular server application engine.
- * Manages Angular server applications (including localized ones), handles rendering requests,
- * and optionally transforms index HTML before rendering.
- */
-class AngularNodeAppEngine implements AngularNodeServerAppManager {
-  private readonly angularAppEngine = getOrCreateAngularAppEngine();
-
-  render(request: IncomingMessage, requestContext?: unknown): Promise<Response | null> {
-    return this.angularAppEngine.render(createWebRequestFromNodeRequest(request), requestContext);
-  }
-
   getHeaders(request: IncomingMessage): Readonly<Map<string, string>> {
     return this.angularAppEngine.getHeaders(createWebRequestFromNodeRequest(request));
   }
 }
-
-let angularNodeAppEngine: AngularNodeAppEngine | undefined;
-
-/**
- * Retrieves the existing `AngularNodeAppEngine` instance or creates a new one if it doesn't exist.
- *
- * This method ensures that a single instance of `AngularNodeAppEngine` is used throughout the application's lifecycle,
- * promoting efficient resource management. If an instance does not exist, it will be instantiated upon the first call.
- *
- * @developerPreview
- * @returns The existing or newly created instance of `AngularNodeAppEngine`.
- */
-export function getOrCreateAngularNodeAppEngine(): AngularNodeServerAppManager {
-  return (angularNodeAppEngine ??= new AngularNodeAppEngine());
-}
-
-/**
- * Destroys the current `AngularNodeAppEngine` instance and releases any associated resources.
- *
- * This method resets the reference to the `AngularNodeAppEngine` instance to `undefined`, allowing for the creation
- * of a new instance on subsequent calls to `getOrCreateAngularNodeAppEngine()`. This is typically used when
- * reinitializing the server environment or refreshing the application state.
- *
- * @developerPreview
- */
-export function destroyAngularNodeAppEngine(): void {
-  angularNodeAppEngine = undefined;
-  destroyAngularAppEngine();
-}

packages/angular/ssr/private_export.ts

@@ -21,6 +21,4 @@ export {
   setAngularAppEngineManifest as ɵsetAngularAppEngineManifest,
 } from './src/manifest';
 
-export { AngularAppEngine as ɵAngularAppEngine } from './src/app-engine';
-
 export { InlineCriticalCssProcessor as ɵInlineCriticalCssProcessor } from './src/utils/inline-critical-css';

packages/angular/ssr/public_api.ts

@@ -8,8 +8,4 @@
 
 export * from './private_export';
 
-export {
-  type AngularServerAppManager,
-  getOrCreateAngularAppEngine,
-  destroyAngularAppEngine,
-} from './src/app-engine';
+export { AngularAppEngine } from './src/app-engine';

packages/angular/ssr/src/app-engine.ts

@@ -12,49 +12,17 @@ import { getPotentialLocaleIdFromUrl } from './i18n';
 import { EntryPointExports, getAngularAppEngineManifest } from './manifest';
 import { stripIndexHtmlFromURL } from './utils/url';
 
-/**
- * Angular server application engine.
- * Manages Angular server applications (including localized ones) and handles rendering requests.
-
- * @developerPreview
- */
-export interface AngularServerAppManager {
-  /**
-   * Renders a response for the given HTTP request using the server application.
-   *
-   * This method processes the request, determines the appropriate route and rendering context,
-   * and returns an HTTP response.
-   *
-   * If the request URL appears to be for a file (excluding `/index.html`), the method returns `null`.
-   * A request to `https://www.example.com/page/index.html` will render the Angular route
-   * corresponding to `https://www.example.com/page`.
-   *
-   * @param request - The incoming HTTP request object to be rendered.
-   * @param requestContext - Optional additional context for the request, such as metadata.
-   * @returns A promise that resolves to a Response object, or `null` if the request URL represents a file (e.g., `./logo.png`)
-   * rather than an application route.
-   */
-  render(request: Request, requestContext?: unknown): Promise<Response | null>;
-
-  /**
-   * Retrieves HTTP headers for a request associated with statically generated (SSG) pages,
-   * based on the URL pathname.
-   *
-   * @param request - The incoming request object.
-   * @returns A `Map` containing the HTTP headers as key-value pairs.
-   * @note This function should be used exclusively for retrieving headers of SSG pages.
-   */
-  getHeaders(request: Request): Readonly<Map<string, string>>;
-}
-
 /**
  * Angular server application engine.
  * Manages Angular server applications (including localized ones), handles rendering requests,
  * and optionally transforms index HTML before rendering.
  *
+ * @note This class should be instantiated once and used as a singleton across the server-side
+ * application to ensure consistent handling of rendering requests and resource management.
+ *
  * @developerPreview
  */
-export class AngularAppEngine implements AngularServerAppManager {
+export class AngularAppEngine {
   /**
    * Hooks for extending or modifying the behavior of the server application.
    * These hooks are used by the Angular CLI when running the development server and
@@ -153,32 +121,3 @@ export class AngularAppEngine implements AngularServerAppManager {
     return new Map(headers);
   }
 }
-
-let angularAppEngine: AngularAppEngine | undefined;
-
-/**
- * Retrieves an existing `AngularAppEngine` instance or creates a new one if none exists.
- *
- * This method ensures that only a single instance of `AngularAppEngine` is created and reused across
- * the application lifecycle, providing efficient resource management. If the instance does not exist,
- * it will be instantiated upon the first call.
- *
- * @developerPreview
- * @returns The existing or newly created instance of `AngularAppEngine`.
- */
-export function getOrCreateAngularAppEngine(): AngularServerAppManager {
-  return (angularAppEngine ??= new AngularAppEngine());
-}
-
-/**
- * Destroys the current `AngularAppEngine` instance, releasing any associated resources.
- *
- * This method resets the reference to the `AngularAppEngine` instance to `undefined`, allowing
- * a new instance to be created on the next call to `getOrCreateAngularAppEngine()`. It is typically
- * used when reinitializing the server environment or refreshing the application state is necessary.
- *
- * @developerPreview
- */
-export function destroyAngularAppEngine(): void {
-  angularAppEngine = undefined;
-}