SSR 404 and 500 routes in adapters (#4018)

* fix(WIP): SSR 404 and 500 routes

* Implement the feature

Co-authored-by: Matthew Phillips <matthew@skypack.dev>

Author: okikio

.changeset/happy-parrots-stare.md

@@ -0,0 +1,8 @@
+---
+'astro': minor
+'@astrojs/cloudflare': minor
+'@astrojs/netlify': minor
+'@astrojs/vercel': minor
+---
+
+Support for 404 and 500 pages in SSR

packages/astro/src/core/app/index.ts

@@ -25,6 +25,10 @@ export { deserializeManifest } from './common.js';
 export const pagesVirtualModuleId = '@astrojs-pages-virtual-entry';
 export const resolvedPagesVirtualModuleId = '\0' + pagesVirtualModuleId;
 
+export interface MatchOptions {
+	matchNotFound?: boolean | undefined;
+}
+
 export class App {
 	#manifest: Manifest;
 	#manifestData: ManifestData;
@@ -46,17 +50,30 @@ export class App {
 		this.#routeCache = new RouteCache(this.#logging);
 		this.#streaming = streaming;
 	}
-	match(request: Request): RouteData | undefined {
+	match(request: Request, { matchNotFound = false }: MatchOptions = {}): RouteData | undefined {
 		const url = new URL(request.url);
 		// ignore requests matching public assets
 		if (this.#manifest.assets.has(url.pathname)) {
 			return undefined;
 		}
-		return matchRoute(url.pathname, this.#manifestData);
+		let routeData = matchRoute(url.pathname, this.#manifestData);
+
+		if(routeData) {
+			return routeData;
+		} else if(matchNotFound) {
+			return matchRoute('/404', this.#manifestData);
+		} else {
+			return undefined;
+		}
 	}
 	async render(request: Request, routeData?: RouteData): Promise<Response> {
+		let defaultStatus = 200;
 		if (!routeData) {
 			routeData = this.match(request);
+			if (!routeData) {
+				defaultStatus = 404;
+				routeData = this.match(request, { matchNotFound: true });
+			}
 			if (!routeData) {
 				return new Response(null, {
 					status: 404,
@@ -65,12 +82,25 @@ export class App {
 			}
 		}
 
-		const mod = this.#manifest.pageMap.get(routeData.component)!;
+		let mod = this.#manifest.pageMap.get(routeData.component)!;
 
 		if (routeData.type === 'page') {
-			return this.#renderPage(request, routeData, mod);
+			let response = await this.#renderPage(request, routeData, mod, defaultStatus);
+
+			// If there was a 500 error, try sending the 500 page.
+			if(response.status === 500) {
+				const fiveHundredRouteData = matchRoute('/500', this.#manifestData);
+				if(fiveHundredRouteData) {
+					mod = this.#manifest.pageMap.get(fiveHundredRouteData.component)!;
+					try {
+						let fiveHundredResponse = await this.#renderPage(request, fiveHundredRouteData, mod, 500);
+						return fiveHundredResponse;
+					} catch {}
+				}
+			}
+			return response;
 		} else if (routeData.type === 'endpoint') {
-			return this.#callEndpoint(request, routeData, mod);
+			return this.#callEndpoint(request, routeData, mod, defaultStatus);
 		} else {
 			throw new Error(`Unsupported route type [${routeData.type}].`);
 		}
@@ -79,7 +109,8 @@ export class App {
 	async #renderPage(
 		request: Request,
 		routeData: RouteData,
-		mod: ComponentInstance
+		mod: ComponentInstance,
+		status = 200
 	): Promise<Response> {
 		const url = new URL(request.url);
 		const manifest = this.#manifest;
@@ -128,6 +159,7 @@ export class App {
 				ssr: true,
 				request,
 				streaming: this.#streaming,
+				status
 			});
 
 			return response;
@@ -143,7 +175,8 @@ export class App {
 	async #callEndpoint(
 		request: Request,
 		routeData: RouteData,
-		mod: ComponentInstance
+		mod: ComponentInstance,
+		status = 200
 	): Promise<Response> {
 		const url = new URL(request.url);
 		const handler = mod as unknown as EndpointHandler;
@@ -155,6 +188,7 @@ export class App {
 			route: routeData,
 			routeCache: this.#routeCache,
 			ssr: true,
+			status
 		});
 
 		if (result.type === 'response') {

packages/astro/src/core/endpoint/index.ts

@@ -5,7 +5,7 @@ import { getParamsAndProps, GetParamsAndPropsError } from '../render/core.js';
 
 export type EndpointOptions = Pick<
 	RenderOptions,
-	'logging' | 'origin' | 'request' | 'route' | 'routeCache' | 'pathname' | 'route' | 'site' | 'ssr'
+	'logging' | 'origin' | 'request' | 'route' | 'routeCache' | 'pathname' | 'route' | 'site' | 'ssr' | 'status'
 >;
 
 type EndpointCallResult =

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

@@ -85,6 +85,7 @@ export interface RenderOptions {
 	ssr: boolean;
 	streaming: boolean;
 	request: Request;
+	status?: number;
 }
 
 export async function render(opts: RenderOptions): Promise<Response> {
@@ -107,6 +108,7 @@ export async function render(opts: RenderOptions): Promise<Response> {
 		site,
 		ssr,
 		streaming,
+		status = 200
 	} = opts;
 
 	const paramsAndPropsRes = await getParamsAndProps({
@@ -148,6 +150,7 @@ export async function render(opts: RenderOptions): Promise<Response> {
 		scripts,
 		ssr,
 		streaming,
+		status
 	});
 
 	// Support `export const components` for `MDX` pages

packages/astro/src/core/render/result.ts

@@ -42,6 +42,7 @@ export interface CreateResultArgs {
 	scripts?: Set<SSRElement>;
 	styles?: Set<SSRElement>;
 	request: Request;
+	status: number;
 }
 
 function getFunctionExpression(slot: any) {
@@ -119,7 +120,7 @@ export function createResult(args: CreateResultArgs): SSRResult {
 		headers.set('Content-Type', 'text/html');
 	}
 	const response: ResponseInit = {
-		status: 200,
+		status: args.status,
 		statusText: 'OK',
 		headers,
 	};

packages/astro/test/fixtures/ssr-api-route-custom-404/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@test/ssr-api-route-custom-404",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}

packages/astro/test/fixtures/ssr-api-route-custom-404/src/pages/404.astro

@@ -0,0 +1 @@
+<h1>Something went horribly wrong!</h1>

packages/astro/test/fixtures/ssr-api-route-custom-404/src/pages/500.astro

@@ -0,0 +1 @@
+<h1>This is an error page</h1>

packages/astro/test/fixtures/ssr-api-route-custom-404/src/pages/causes-error.astro

@@ -0,0 +1,3 @@
+---
+throw new Error(`oops`);
+---

packages/astro/test/ssr-404-500-pages.test.js

@@ -0,0 +1,40 @@
+import { expect } from 'chai';
+import { loadFixture } from './test-utils.js';
+import testAdapter from './test-adapter.js';
+import * as cheerio from 'cheerio';
+
+describe('404 and 500 pages', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/ssr-api-route-custom-404/',
+			experimental: {
+				ssr: true,
+			},
+			adapter: testAdapter(),
+		});
+		await fixture.build({  });
+	});
+
+	it('404 page returned when a route does not match', async () => {
+		const app = await fixture.loadTestAdapterApp();
+		const request = new Request('http://example.com/some/fake/route');
+		const response = await app.render(request);
+		expect(response.status).to.equal(404);
+		const html = await response.text();
+		const $ = cheerio.load(html);
+		expect($('h1').text()).to.equal('Something went horribly wrong!');
+	});
+
+	it('500 page returned when there is an error', async () => {
+		const app = await fixture.loadTestAdapterApp();
+		const request = new Request('http://example.com/causes-error');
+		const response = await app.render(request);
+		expect(response.status).to.equal(500);
+		const html = await response.text();
+		const $ = cheerio.load(html);
+		expect($('h1').text()).to.equal('This is an error page');
+	});
+});