fix(@angular/ssr): support getPrerenderParams for wildcard routes

Handle `getPrerenderParams` return values when used with wildcard route paths.
Supports returning an array of path segments (e.g., `['category', '123']`) for `**` routes.

This enables more flexible prerendering configurations in server routes.

Example:
```ts
{
  path: '/product/**',
  renderMode: RenderMode.Prerender,
  async getPrerenderParams() {
    return [['category', '1'], ['category', '2']];
  }
}
```

Closes angular#30035

Author: alan-agius4

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

@@ -63,7 +63,7 @@ export interface ServerRoutePrerender extends Omit<ServerRouteCommon, 'status'>
 // @public
 export interface ServerRoutePrerenderWithParams extends Omit<ServerRoutePrerender, 'fallback'> {
     fallback?: PrerenderFallback;
-    getPrerenderParams: () => Promise<Record<string, string>[]>;
+    getPrerenderParams: () => Promise<(string[] | Record<string, string>)[]>;
 }
 
 // @public

packages/angular/ssr/src/routes/ng-routes.ts

@@ -391,7 +391,8 @@ async function* handleSSGRoute(
     meta.redirectTo = resolveRedirectTo(currentRoutePath, redirectTo);
   }
 
-  if (!URL_PARAMETER_REGEXP.test(currentRoutePath)) {
+  const isWildcardRoute = currentRoutePath.includes('**');
+  if (!isWildcardRoute && !URL_PARAMETER_REGEXP.test(currentRoutePath)) {
     // Route has no parameters
     yield {
       ...meta,
@@ -402,7 +403,7 @@ async function* handleSSGRoute(
   }
 
   if (invokeGetPrerenderParams) {
-    if (!getPrerenderParams) {
+    if (!getPrerenderParams && !isWildcardRoute) {
       yield {
         error:
           `The '${stripLeadingSlash(currentRoutePath)}' route uses prerendering and includes parameters, but 'getPrerenderParams' ` +
@@ -415,7 +416,9 @@ async function* handleSSGRoute(
 
     if (serverConfigRouteTree) {
       // Automatically resolve dynamic parameters for nested routes.
-      const catchAllRoutePath = joinUrlParts(currentRoutePath, '**');
+      const catchAllRoutePath = currentRoutePath.endsWith('**')
+        ? currentRoutePath
+        : joinUrlParts(currentRoutePath, '**');
       const match = serverConfigRouteTree.match(catchAllRoutePath);
       if (match && match.renderMode === RenderMode.Prerender && !('getPrerenderParams' in match)) {
         serverConfigRouteTree.insert(catchAllRoutePath, {
@@ -429,20 +432,39 @@ async function* handleSSGRoute(
     const parameters = await runInInjectionContext(parentInjector, () => getPrerenderParams());
     try {
       for (const params of parameters) {
-        const routeWithResolvedParams = currentRoutePath.replace(URL_PARAMETER_REGEXP, (match) => {
-          const parameterName = match.slice(1);
-          const value = params[parameterName];
-          if (typeof value !== 'string') {
+        const isWildcardRoute = currentRoutePath.includes('**');
+        const isParamsArray = Array.isArray(params);
+
+        if (isParamsArray) {
+          if (!isWildcardRoute) {
             throw new Error(
-              `The 'getPrerenderParams' function defined for the '${stripLeadingSlash(currentRoutePath)}' route ` +
-                `returned a non-string value for parameter '${parameterName}'. ` +
-                `Please make sure the 'getPrerenderParams' function returns values for all parameters ` +
-                'specified in this route.',
+              `The 'getPrerenderParams' function for the '${stripLeadingSlash(currentRoutePath)}' ` +
+                `route returned an array '${JSON.stringify(params)}', which is not valid for catch-all routes.`,
             );
           }
+        } else if (isWildcardRoute) {
+          throw new Error(
+            `The 'getPrerenderParams' function for the '${stripLeadingSlash(currentRoutePath)}' ` +
+              `route returned an object '${JSON.stringify(params)}', which is not valid for parameterized routes.`,
+          );
+        }
 
-          return value;
-        });
+        const routeWithResolvedParams = isParamsArray
+          ? currentRoutePath.replace('**', params.join('/'))
+          : currentRoutePath.replace(URL_PARAMETER_REGEXP, (match) => {
+              const parameterName = match.slice(1);
+              const value = params[parameterName];
+              if (typeof value !== 'string') {
+                throw new Error(
+                  `The 'getPrerenderParams' function defined for the '${stripLeadingSlash(currentRoutePath)}' route ` +
+                    `returned a non-string value for parameter '${parameterName}'. ` +
+                    `Please make sure the 'getPrerenderParams' function returns values for all parameters ` +
+                    'specified in this route.',
+                );
+              }
+
+              return value;
+            });
 
         yield {
           ...meta,
@@ -530,9 +552,9 @@ function buildServerConfigRouteTree({ routes, appShellRoute }: ServerRoutesConfi
       continue;
     }
 
-    if (path.includes('*') && 'getPrerenderParams' in metadata) {
+    if (!path.includes('**') && path.includes('*') && 'getPrerenderParams' in metadata) {
       errors.push(
-        `Invalid '${path}' route configuration: 'getPrerenderParams' cannot be used with a '*' or '**' route.`,
+        `Invalid '${path}' route configuration: 'getPrerenderParams' cannot be used with a '*' route.`,
       );
       continue;
     }

packages/angular/ssr/src/routes/route-config.ts

@@ -142,8 +142,17 @@ export interface ServerRoutePrerenderWithParams extends Omit<ServerRoutePrerende
    * A function that returns a Promise resolving to an array of objects, each representing a route path with URL parameters.
    * This function runs in the injector context, allowing access to Angular services and dependencies.
    *
-   * @returns A Promise resolving to an array where each element is an object with string keys (representing URL parameter names)
-   * and string values (representing the corresponding values for those parameters in the route path).
+   * @returns A Promise resolving to an array of values that define route parameters for prerendering:
+   *
+   * - If the route `path` contains named parameters (e.g., `/product/:id`), each element should be an object
+   *   where keys are parameter names and values are their corresponding values.
+   *   Example: `{ id: '123' }` results in `/product/123`.
+   *
+   * - If the route `path` uses a catch-all (`**`) or wildcard structure (e.g., `/product/**`), each element should
+   *   be a string array representing full path segments.
+   *   Example: `['category', '123']` results in `/product/category/123`.
+   *
+   * The array returned determines the number of prerendered routes generated for a given configuration.
    *
    * @example
    * ```typescript
@@ -160,8 +169,24 @@ export interface ServerRoutePrerenderWithParams extends Omit<ServerRoutePrerende
    *   },
    * ];
    * ```
+   *
+   * @example
+   * ```typescript
+   * export const serverRouteConfig: ServerRoutes[] = [
+   *   {
+   *     path: '/product/**',
+   *     renderMode: RenderMode.Prerender,
+   *     async getPrerenderParams() {
+   *       const productService = inject(ProductService);
+   *       const ids = await productService.getIds(); // Assuming this returns ['1', '2', '3']
+   *
+   *       return ids.map(id => (['category', id])); // Generates paths like: [['category', '1'], ['category', '2'], ['category', '3']]
+   *     },
+   *   },
+   * ];
+   * ```
    */
-  getPrerenderParams: () => Promise<Record<string, string>[]>;
+  getPrerenderParams: () => Promise<(string[] | Record<string, string>)[]>;
 }
 
 /**

packages/angular/ssr/test/routes/ng-routes_spec.ts

@@ -68,26 +68,6 @@ describe('extractRoutesAndCreateRouteTree', () => {
       );
     });
 
-    it("should error when 'getPrerenderParams' is used with a '**' route", async () => {
-      setAngularAppTestingManifest(
-        [{ path: 'home', component: DummyComponent }],
-        [
-          {
-            path: '**',
-            renderMode: RenderMode.Prerender,
-            getPrerenderParams() {
-              return Promise.resolve([]);
-            },
-          },
-        ],
-      );
-
-      const { errors } = await extractRoutesAndCreateRouteTree({ url });
-      expect(errors[0]).toContain(
-        "Invalid '**' route configuration: 'getPrerenderParams' cannot be used with a '*' or '**' route.",
-      );
-    });
-
     it("should error when 'getPrerenderParams' is used with a '*' route", async () => {
       setAngularAppTestingManifest(
         [{ path: 'invalid/:id', component: DummyComponent }],
@@ -104,7 +84,7 @@ describe('extractRoutesAndCreateRouteTree', () => {
 
       const { errors } = await extractRoutesAndCreateRouteTree({ url });
       expect(errors[0]).toContain(
-        "Invalid 'invalid/*' route configuration: 'getPrerenderParams' cannot be used with a '*' or '**' route.",
+        "Invalid 'invalid/*' route configuration: 'getPrerenderParams' cannot be used with a '*' route.",
       );
     });
 
@@ -296,6 +276,44 @@ describe('extractRoutesAndCreateRouteTree', () => {
       ]);
     });
 
+    it('should resolve catch all routes for SSG and not add a fallback route if fallback is Server', async () => {
+      setAngularAppTestingManifest(
+        [
+          { path: 'home', component: DummyComponent },
+          { path: 'user/**', component: DummyComponent },
+        ],
+        [
+          {
+            path: 'user/**',
+            renderMode: RenderMode.Prerender,
+            fallback: PrerenderFallback.Server,
+            async getPrerenderParams() {
+              return [
+                ['joe', 'role', 'admin'],
+                ['jane', 'role', 'writer'],
+              ];
+            },
+          },
+          { path: '**', renderMode: RenderMode.Server },
+        ],
+      );
+
+      const { routeTree, errors } = await extractRoutesAndCreateRouteTree({
+        url,
+        invokeGetPrerenderParams: true,
+      });
+      expect(errors).toHaveSize(0);
+      expect(routeTree.toObject()).toEqual([
+        { route: '/home', renderMode: RenderMode.Server },
+        { route: '/user/joe/role/admin', renderMode: RenderMode.Prerender },
+        {
+          route: '/user/jane/role/writer',
+          renderMode: RenderMode.Prerender,
+        },
+        { route: '/user/**', renderMode: RenderMode.Server },
+      ]);
+    });
+
     it('should extract nested redirects that are not explicitly defined.', async () => {
       setAngularAppTestingManifest(
         [