feat: reroute in SSG (#10843)

* feat: rerouting in ssg

* linting

packages/astro/src/core/build/generate.ts

@@ -35,24 +35,14 @@ import { getOutputDirectory, isServerLikeOutput } from '../../prerender/utils.js
 import type { SSRManifestI18n } from '../app/types.js';
 import { NoPrerenderedRoutesWithDomains } from '../errors/errors-data.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
-import { routeIsFallback } from '../redirects/helpers.js';
-import {
-	RedirectSinglePageBuiltModule,
-	getRedirectLocationOrThrow,
-	routeIsRedirect,
-} from '../redirects/index.js';
+import { getRedirectLocationOrThrow, routeIsRedirect } from '../redirects/index.js';
 import { RenderContext } from '../render-context.js';
 import { callGetStaticPaths } from '../render/route-cache.js';
 import { createRequest } from '../request.js';
 import { matchRoute } from '../routing/match.js';
 import { getOutputFilename } from '../util.js';
 import { getOutDirWithinCwd, getOutFile, getOutFolder } from './common.js';
-import {
-	cssOrder,
-	getEntryFilePathFromComponentPath,
-	getPageDataByComponent,
-	mergeInlineCss,
-} from './internal.js';
+import { cssOrder, getPageDataByComponent, mergeInlineCss } from './internal.js';
 import { BuildPipeline } from './pipeline.js';
 import type {
 	PageBuildData,
@@ -66,46 +56,6 @@ function createEntryURL(filePath: string, outFolder: URL) {
 	return new URL('./' + filePath + `?time=${Date.now()}`, outFolder);
 }
 
-async function getEntryForRedirectRoute(
-	route: RouteData,
-	internals: BuildInternals,
-	outFolder: URL
-): Promise<SinglePageBuiltModule> {
-	if (route.type !== 'redirect') {
-		throw new Error(`Expected a redirect route.`);
-	}
-	if (route.redirectRoute) {
-		const filePath = getEntryFilePathFromComponentPath(internals, route.redirectRoute.component);
-		if (filePath) {
-			const url = createEntryURL(filePath, outFolder);
-			const ssrEntryPage: SinglePageBuiltModule = await import(url.toString());
-			return ssrEntryPage;
-		}
-	}
-
-	return RedirectSinglePageBuiltModule;
-}
-
-async function getEntryForFallbackRoute(
-	route: RouteData,
-	internals: BuildInternals,
-	outFolder: URL
-): Promise<SinglePageBuiltModule> {
-	if (route.type !== 'fallback') {
-		throw new Error(`Expected a redirect route.`);
-	}
-	if (route.redirectRoute) {
-		const filePath = getEntryFilePathFromComponentPath(internals, route.redirectRoute.component);
-		if (filePath) {
-			const url = createEntryURL(filePath, outFolder);
-			const ssrEntryPage: SinglePageBuiltModule = await import(url.toString());
-			return ssrEntryPage;
-		}
-	}
-
-	return RedirectSinglePageBuiltModule;
-}
-
 // Gives back a facadeId that is relative to the root.
 // ie, src/pages/index.astro instead of /Users/name..../src/pages/index.astro
 export function rootRelativeFacadeId(facadeId: string, settings: AstroSettings): string {
@@ -185,14 +135,15 @@ export async function generatePages(options: StaticBuildOptions, internals: Buil
 					});
 				}
 
-				const ssrEntryURLPage = createEntryURL(filePath, outFolder);
-				const ssrEntryPage = await import(ssrEntryURLPage.toString());
+				const ssrEntryPage = await pipeline.retrieveSsrEntry(pageData.route, filePath);
 				if (options.settings.adapter?.adapterFeatures?.functionPerRoute) {
 					// forcing to use undefined, so we fail in an expected way if the module is not even there.
+					// @ts-expect-error When building for `functionPerRoute`, the module exports a `pageModule` function instead
 					const ssrEntry = ssrEntryPage?.pageModule;
 					if (ssrEntry) {
 						await generatePage(pageData, ssrEntry, builtPaths, pipeline);
 					} else {
+						const ssrEntryURLPage = createEntryURL(filePath, outFolder);
 						throw new Error(
 							`Unable to find the manifest for the module ${ssrEntryURLPage.toString()}. This is unexpected and likely a bug in Astro, please report.`
 						);
@@ -205,18 +156,8 @@ export async function generatePages(options: StaticBuildOptions, internals: Buil
 		}
 	} else {
 		for (const [pageData, filePath] of pagesToGenerate) {
-			if (routeIsRedirect(pageData.route)) {
-				const entry = await getEntryForRedirectRoute(pageData.route, internals, outFolder);
-				await generatePage(pageData, entry, builtPaths, pipeline);
-			} else if (routeIsFallback(pageData.route)) {
-				const entry = await getEntryForFallbackRoute(pageData.route, internals, outFolder);
-				await generatePage(pageData, entry, builtPaths, pipeline);
-			} else {
-				const ssrEntryURLPage = createEntryURL(filePath, outFolder);
-				const entry: SinglePageBuiltModule = await import(ssrEntryURLPage.toString());
-
-				await generatePage(pageData, entry, builtPaths, pipeline);
-			}
+			const entry = await pipeline.retrieveSsrEntry(pageData.route, filePath);
+			await generatePage(pageData, entry, builtPaths, pipeline);
 		}
 	}
 	logger.info(
@@ -232,12 +173,12 @@ export async function generatePages(options: StaticBuildOptions, internals: Buil
 			.map((x) => x.transforms.size)
 			.reduce((a, b) => a + b, 0);
 		const cpuCount = os.cpus().length;
-		const assetsCreationpipeline = await prepareAssetsGenerationEnv(pipeline, totalCount);
+		const assetsCreationPipeline = await prepareAssetsGenerationEnv(pipeline, totalCount);
 		const queue = new PQueue({ concurrency: Math.max(cpuCount, 1) });
 
 		const assetsTimer = performance.now();
 		for (const [originalPath, transforms] of staticImageList) {
-			await generateImagesForPath(originalPath, transforms, assetsCreationpipeline, queue);
+			await generateImagesForPath(originalPath, transforms, assetsCreationPipeline, queue);
 		}
 
 		await queue.onIdle();

packages/astro/src/core/build/pipeline.ts

@@ -1,10 +1,9 @@
 import type {
+	ComponentInstance,
+	ReroutePayload,
 	RouteData,
 	SSRLoadedRenderer,
 	SSRResult,
-	MiddlewareHandler,
-	ReroutePayload,
-	ComponentInstance,
 } from '../../@types/astro.js';
 import { getOutputDirectory, isServerLikeOutput } from '../../prerender/utils.js';
 import { BEFORE_HYDRATION_SCRIPT_ID, PAGE_SCRIPT_ID } from '../../vite-plugin-scripts/index.js';
@@ -19,22 +18,42 @@ import {
 import {
 	type BuildInternals,
 	cssOrder,
+	getEntryFilePathFromComponentPath,
 	getPageDataByComponent,
 	mergeInlineCss,
 } from './internal.js';
 import { ASTRO_PAGE_MODULE_ID, ASTRO_PAGE_RESOLVED_MODULE_ID } from './plugins/plugin-pages.js';
 import { RESOLVED_SPLIT_MODULE_ID } from './plugins/plugin-ssr.js';
-import { getVirtualModulePageNameFromPath } from './plugins/util.js';
-import { ASTRO_PAGE_EXTENSION_POST_PATTERN } from './plugins/util.js';
-import type { PageBuildData, StaticBuildOptions } from './types.js';
+import {
+	ASTRO_PAGE_EXTENSION_POST_PATTERN,
+	getVirtualModulePageNameFromPath,
+} from './plugins/util.js';
+import type { PageBuildData, SinglePageBuiltModule, StaticBuildOptions } from './types.js';
 import { i18nHasFallback } from './util.js';
-import { defineMiddleware } from '../middleware/index.js';
-import { undefined } from 'zod';
+import { RedirectSinglePageBuiltModule } from '../redirects/index.js';
+import { getOutDirWithinCwd } from './common.js';
 
 /**
  * The build pipeline is responsible to gather the files emitted by the SSR build and generate the pages by executing these files.
  */
 export class BuildPipeline extends Pipeline {
+	#componentsInterner: WeakMap<RouteData, SinglePageBuiltModule> = new WeakMap<
+		RouteData,
+		SinglePageBuiltModule
+	>();
+	/**
+	 * This cache is needed to map a single `RouteData` to its file path.
+	 * @private
+	 */
+	#routesByFilePath: WeakMap<RouteData, string> = new WeakMap<RouteData, string>();
+
+	get outFolder() {
+		const ssr = isServerLikeOutput(this.settings.config);
+		return ssr
+			? this.settings.config.build.server
+			: getOutDirWithinCwd(this.settings.config.outDir);
+	}
+
 	private constructor(
 		readonly internals: BuildInternals,
 		readonly manifest: SSRManifest,
@@ -232,14 +251,115 @@ export class BuildPipeline extends Pipeline {
 			}
 		}
 
+		for (const [buildData, filePath] of pages.entries()) {
+			this.#routesByFilePath.set(buildData.route, filePath);
+		}
+
 		return pages;
 	}
 
-	getComponentByRoute(_routeData: RouteData): Promise<ComponentInstance> {
-		throw new Error('unimplemented');
+	async getComponentByRoute(routeData: RouteData): Promise<ComponentInstance> {
+		if (this.#componentsInterner.has(routeData)) {
+			// SAFETY: checked before
+			const entry = this.#componentsInterner.get(routeData)!;
+			return await entry.page();
+		} else {
+			// SAFETY: the pipeline calls `retrieveRoutesToGenerate`, which is in charge to fill the cache.
+			const filePath = this.#routesByFilePath.get(routeData)!;
+			const module = await this.retrieveSsrEntry(routeData, filePath);
+			return module.page();
+		}
 	}
 
-	tryReroute(_reroutePayload: ReroutePayload): Promise<[RouteData, ComponentInstance]> {
-		throw new Error('unimplemented');
+	async tryReroute(payload: ReroutePayload): Promise<[RouteData, ComponentInstance]> {
+		let foundRoute: RouteData | undefined;
+		// options.manifest is the actual type that contains the information
+		for (const route of this.options.manifest.routes) {
+			if (payload instanceof URL) {
+				if (route.pattern.test(payload.pathname)) {
+					foundRoute = route;
+					break;
+				}
+			} else if (payload instanceof Request) {
+				const url = new URL(payload.url);
+				if (route.pattern.test(url.pathname)) {
+					foundRoute = route;
+					break;
+				}
+			} else {
+				if (route.pattern.test(decodeURI(payload))) {
+					foundRoute = route;
+					break;
+				}
+			}
+		}
+		if (foundRoute) {
+			const componentInstance = await this.getComponentByRoute(foundRoute);
+			return [foundRoute, componentInstance];
+		} else {
+			throw new Error('Route not found');
+		}
 	}
+
+	async retrieveSsrEntry(route: RouteData, filePath: string): Promise<SinglePageBuiltModule> {
+		if (this.#componentsInterner.has(route)) {
+			// SAFETY: it is checked inside the if
+			return this.#componentsInterner.get(route)!;
+		}
+		let entry;
+		if (routeIsRedirect(route)) {
+			entry = await this.#getEntryForRedirectRoute(route, this.internals, this.outFolder);
+		} else if (routeIsFallback(route)) {
+			entry = await this.#getEntryForFallbackRoute(route, this.internals, this.outFolder);
+		} else {
+			const ssrEntryURLPage = createEntryURL(filePath, this.outFolder);
+			entry = await import(ssrEntryURLPage.toString());
+		}
+		this.#componentsInterner.set(route, entry);
+		return entry;
+	}
+
+	async #getEntryForFallbackRoute(
+		route: RouteData,
+		internals: BuildInternals,
+		outFolder: URL
+	): Promise<SinglePageBuiltModule> {
+		if (route.type !== 'fallback') {
+			throw new Error(`Expected a redirect route.`);
+		}
+		if (route.redirectRoute) {
+			const filePath = getEntryFilePathFromComponentPath(internals, route.redirectRoute.component);
+			if (filePath) {
+				const url = createEntryURL(filePath, outFolder);
+				const ssrEntryPage: SinglePageBuiltModule = await import(url.toString());
+				return ssrEntryPage;
+			}
+		}
+
+		return RedirectSinglePageBuiltModule;
+	}
+
+	async #getEntryForRedirectRoute(
+		route: RouteData,
+		internals: BuildInternals,
+		outFolder: URL
+	): Promise<SinglePageBuiltModule> {
+		if (route.type !== 'redirect') {
+			throw new Error(`Expected a redirect route.`);
+		}
+		if (route.redirectRoute) {
+			const filePath = getEntryFilePathFromComponentPath(internals, route.redirectRoute.component);
+			if (filePath) {
+				const url = createEntryURL(filePath, outFolder);
+				const ssrEntryPage: SinglePageBuiltModule = await import(url.toString());
+				return ssrEntryPage;
+			}
+		}
+
+		return RedirectSinglePageBuiltModule;
+	}
+}
+
+function createEntryURL(filePath: string, outFolder: URL) {
+	return new URL('./' + filePath + `?time=${Date.now()}`, outFolder);
 }

packages/astro/src/core/render-context.ts

@@ -195,6 +195,7 @@ export class RenderContext {
 			new Response(null, { status, headers: { Location: path } });
 
 		const reroute = async (reroutePayload: ReroutePayload) => {
+			pipeline.logger.debug('router', 'Called rerouting to:', reroutePayload);
 			try {
 				const [routeData, component] = await pipeline.tryReroute(reroutePayload);
 				this.routeData = routeData;
@@ -212,6 +213,7 @@ export class RenderContext {
 				this.isRerouting = true;
 				return await this.render(component);
 			} catch (e) {
+				pipeline.logger.debug('router', 'Routing failed.', e);
 				return new Response('Not found', {
 					status: 404,
 					statusText: 'Not found',
@@ -336,6 +338,7 @@ export class RenderContext {
 
 		const reroute = async (reroutePayload: ReroutePayload) => {
 			try {
+				pipeline.logger.debug('router', 'Calling rerouting: ', reroutePayload);
 				const [routeData, component] = await pipeline.tryReroute(reroutePayload);
 				this.routeData = routeData;
 				if (reroutePayload instanceof Request) {
@@ -352,6 +355,7 @@ export class RenderContext {
 				this.isRerouting = true;
 				return await this.render(component);
 			} catch (e) {
+				pipeline.logger.debug('router', 'Rerouting failed, returning a 404.', e);
 				return new Response('Not found', {
 					status: 404,
 					statusText: 'Not found',

packages/astro/src/vite-plugin-astro-server/pipeline.ts

@@ -203,7 +203,11 @@ export class DevPipeline extends Pipeline {
 					break;
 				}
 			} else if (payload instanceof Request) {
-				// TODO: handle request, if needed
+				const url = new URL(payload.url);
+				if (route.pattern.test(url.pathname)) {
+					foundRoute = route;
+					break;
+				}
 			} else {
 				if (route.pattern.test(decodeURI(payload))) {
 					foundRoute = route;

packages/astro/src/vite-plugin-astro-server/route.ts

@@ -222,6 +222,7 @@ export async function handleRoute({
 			fallbackRoutes: [],
 			isIndex: false,
 		};
+
 		renderContext = RenderContext.create({
 			pipeline: pipeline,
 			pathname,

packages/astro/test/fixtures/reroute/src/pages/dynamic/[id].astro

@@ -0,0 +1,21 @@
+---
+
+export function getStaticPaths() {
+	return [
+		{ params: { id: 'hello' } },
+	];
+}
+
+
+return Astro.reroute("/")
+
+---
+
+<html>
+<head>
+	<title>Dynamic [id].astro</title>
+</head>
+<body>
+<h1>/dynamic/[id].astro</h1>
+</body>
+</html>