fix(@angular/ssr): initialize the DI tokens with null to avoid requiring them to be set to optional

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

@@ -7,13 +7,13 @@
 import { InjectionToken } from '@angular/core';
 
 // @public
-export const REQUEST: InjectionToken<Request>;
+export const REQUEST: InjectionToken<Request | null>;
 
 // @public
 export const REQUEST_CONTEXT: InjectionToken<unknown>;
 
 // @public
-export const RESPONSE_INIT: InjectionToken<ResponseInit>;
+export const RESPONSE_INIT: InjectionToken<ResponseInit | null>;
 
 // (No @packageDocumentation comment for this package)
 

packages/angular/ssr/tokens/src/tokens.ts

@@ -9,19 +9,62 @@
 import { InjectionToken } from '@angular/core';
 
 /**
- * Injection token for the current request.
+ * Injection token representing the current HTTP request object.
+ *
+ * Use this token to access the current request when handling server-side
+ * rendering (SSR).
+ *
+ * @remarks
+ * This token may be `null` in the following scenarios:
+ *
+ * * During the build processes.
+ * * When the application is rendered in the browser (client-side rendering).
+ * * When performing static site generation (SSG).
+ * * During route extraction in development (at the time of the request).
+ *
+ * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/Request | `Request` on MDN}
+ *
  * @developerPreview
  */
-export const REQUEST = new InjectionToken<Request>('REQUEST');
+export const REQUEST = new InjectionToken<Request | null>('REQUEST', {
+  providedIn: 'platform',
+  factory: () => null,
+});
 
 /**
- * Injection token for the response initialization options.
+ * Injection token for response initialization options.
+ *
+ * Use this token to provide response options for configuring or initializing
+ * HTTP responses in server-side rendering or API endpoints.
+ *
+ * @remarks
+ * This token may be `null` in the following scenarios:
+ *
+ * * During the build processes.
+ * * When the application is rendered in the browser (client-side rendering).
+ * * When performing static site generation (SSG).
+ * * During route extraction in development (at the time of the request).
+ *
+ * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/Response/Response | `ResponseInit` on MDN}
+ *
  * @developerPreview
  */
-export const RESPONSE_INIT = new InjectionToken<ResponseInit>('RESPONSE_INIT');
+export const RESPONSE_INIT = new InjectionToken<ResponseInit | null>('RESPONSE_INIT', {
+  providedIn: 'platform',
+  factory: () => null,
+});
 
 /**
  * Injection token for additional request context.
+ *
+ * Use this token to pass custom metadata or context related to the current request in server-side rendering.
+ *
+ * @remarks
+ * This token is only available during server-side rendering and will be `null` in other contexts.
+ *
  * @developerPreview
  */
-export const REQUEST_CONTEXT = new InjectionToken<unknown>('REQUEST_CONTEXT');
+export const REQUEST_CONTEXT = new InjectionToken<unknown>('REQUEST_CONTEXT', {
+  providedIn: 'platform',
+  factory: () => null,
+});