Support prerender in Netlify redirects (#5904)

* Support prerender in Netlify redirects

* Updated sorting algorithm

* Update packages/integrations/netlify/src/shared.ts

Co-authored-by: Bjorn Lu <bjornlu.dev@gmail.com>

Co-authored-by: Bjorn Lu <bjornlu.dev@gmail.com>

12 files changed, 240 insertions, 17 deletions

diff --git a/.changeset/real-rules-occur.md b/.changeset/real-rules-occur.md
new file mode 100644
index 000000000..10133a059
--- /dev/null
+++ b/.changeset/real-rules-occur.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/netlify': patch
+---
+
+Support prerender in \_redirects
diff --git a/packages/integrations/netlify/src/integration-edge-functions.ts b/packages/integrations/netlify/src/integration-edge-functions.ts
index d443e1c0b..0d036be93 100644
--- a/packages/integrations/netlify/src/integration-edge-functions.ts
+++ b/packages/integrations/netlify/src/integration-edge-functions.ts
@@ -163,7 +163,7 @@ export function netlifyEdgeFunctions({ dist }: NetlifyEdgeFunctionsOptions = {})
 			'astro:build:done': async ({ routes, dir }) => {
 				await bundleServerEntry(_buildConfig, _vite);
 				await createEdgeManifest(routes, entryFile, _config.root);
-				await createRedirects(routes, dir, entryFile, true);
+				await createRedirects(_config, routes, dir, entryFile, true);
 			},
 		},
 	};
diff --git a/packages/integrations/netlify/src/integration-functions.ts b/packages/integrations/netlify/src/integration-functions.ts
index e8ff4bd1f..f75b6d1f8 100644
--- a/packages/integrations/netlify/src/integration-functions.ts
+++ b/packages/integrations/netlify/src/integration-functions.ts
@@ -48,7 +48,7 @@ function netlifyFunctions({
 				}
 			},
 			'astro:build:done': async ({ routes, dir }) => {
-				await createRedirects(routes, dir, entryFile, false);
+				await createRedirects(_config, routes, dir, entryFile, false);
 			},
 		},
 	};
diff --git a/packages/integrations/netlify/src/shared.ts b/packages/integrations/netlify/src/shared.ts
index 2c648984a..c87d946f5 100644
--- a/packages/integrations/netlify/src/shared.ts
+++ b/packages/integrations/netlify/src/shared.ts
@@ -1,7 +1,16 @@
-import type { RouteData } from 'astro';
+import type { AstroConfig, RouteData } from 'astro';
 import fs from 'fs';
 
+type RedirectDefinition = {
+	dynamic: boolean;
+	input: string;
+	target: string;
+	weight: 0 | 1;
+	status: 200 | 404;
+};
+
 export async function createRedirects(
+	config: AstroConfig,
 	routes: RouteData[],
 	dir: URL,
 	entryFile: string,
@@ -10,37 +19,116 @@ export async function createRedirects(
 	const _redirectsURL = new URL('./_redirects', dir);
 	const kind = edge ? 'edge-functions' : 'functions';
 
-	// Create the redirects file that is used for routing.
-	let _redirects = '';
+	const definitions: RedirectDefinition[] = [];
+
 	for (const route of routes) {
 		if (route.pathname) {
 			if (route.distURL) {
-				_redirects += `
-  ${route.pathname}   /${route.distURL.toString().replace(dir.toString(), '')}    200`;
+				definitions.push({
+					dynamic: false,
+					input: route.pathname,
+					target: prependForwardSlash(route.distURL.toString().replace(dir.toString(), '')),
+					status: 200,
+					weight: 1
+				});
 			} else {
-				_redirects += `
-  ${route.pathname}    /.netlify/${kind}/${entryFile}    200`;
+				definitions.push({
+					dynamic: false,
+					input: route.pathname,
+					target: `/.netlify/${kind}/${entryFile}`,
+					status: 200,
+					weight: 1,
+				});
 
 				if (route.route === '/404') {
-					_redirects += `
-  /*    /.netlify/${kind}/${entryFile}    404`;
+					definitions.push({
+						dynamic: true,
+						input: '/*',
+						target: `/.netlify/${kind}/${entryFile}`,
+						status: 404,
+						weight: 0
+					});
 				}
 			}
 		} else {
 			const pattern =
-				'/' + route.segments.map(([part]) => (part.dynamic ? '*' : part.content)).join('/');
+				'/' + route.segments.map(([part]) => {
+					//(part.dynamic ? '*' : part.content)
+					if(part.dynamic) {
+						if(part.spread) {
+							return '*';
+						} else {
+							return ':' + part.content;
+						}
+					} else {
+						return part.content;
+					}
+				}).join('/');
+
 			if (route.distURL) {
-				_redirects += `
-  ${pattern}   /${route.distURL.toString().replace(dir.toString(), '')}    200`;
+				const target = `${pattern}` + (config.build.format === 'directory' ? '/index.html' : '.html');
+				definitions.push({
+					dynamic: true,
+					input: pattern,
+					target,
+					status: 200,
+					weight: 1
+				});
 			} else {
-				_redirects += `
-  ${pattern}    /.netlify/${kind}/${entryFile}    200`;
+				definitions.push({
+					dynamic: true,
+					input: pattern,
+					target: `/.netlify/${kind}/${entryFile}`,
+					status: 200,
+					weight: 1
+				});
 			}
 		}
 	}
 
+	let _redirects = prettify(definitions);
+
 	// Always use appendFile() because the redirects file could already exist,
 	// e.g. due to a `/public/_redirects` file that got copied to the output dir.
 	// If the file does not exist yet, appendFile() automatically creates it.
 	await fs.promises.appendFile(_redirectsURL, _redirects, 'utf-8');
 }
+
+function prettify(definitions: RedirectDefinition[]) {
+	let minInputLength = 0, minTargetLength = 0;
+	definitions.sort((a, b) => {
+		// Find the longest input, so we can format things nicely
+		if(a.input.length > minInputLength) {
+			minInputLength = a.input.length;
+		}
+		if(b.input.length > minInputLength) {
+			minInputLength = b.input.length;
+		}
+
+		// Same for the target
+		if(a.target.length > minTargetLength) {
+			minTargetLength = a.target.length;
+		}
+		if(b.target.length > minTargetLength) {
+			minTargetLength = b.target.length;
+		}
+
+		// Sort dynamic routes on top
+		return b.weight - a.weight;
+	});
+
+	let _redirects = '';
+	// Loop over the definitions
+	definitions.forEach((defn, i) => {
+		// Figure out the number of spaces to add. We want at least 4 spaces
+		// after the input. This ensure that all targets line up together.
+		let inputSpaces = (minInputLength - defn.input.length) + 4;
+		let targetSpaces = (minTargetLength - defn.target.length) + 4;
+		_redirects += (i === 0 ? '' : '\n') + defn.input + ' '.repeat(inputSpaces) + defn.target + ' '.repeat(Math.abs(targetSpaces)) + defn.status;
+	});
+	return _redirects;
+}
+
+function prependForwardSlash(str: string) {
+	return str[0] === '/' ? str : '/' + str;
+}
diff --git a/packages/integrations/netlify/test/functions/dynamic-route.test.js b/packages/integrations/netlify/test/functions/dynamic-route.test.js
index 0cfb5359b..6bb68eab8 100644
--- a/packages/integrations/netlify/test/functions/dynamic-route.test.js
+++ b/packages/integrations/netlify/test/functions/dynamic-route.test.js
@@ -21,6 +21,13 @@ describe('Dynamic pages', () => {
 
 	it('Dynamic pages are included in the redirects file', async () => {
 		const redir = await fixture.readFile('/_redirects');
-		expect(redir).to.match(/\/products\/\*/);
+		expect(redir).to.match(/\/products\/:id/);
+	});
+
+	it('Prerendered routes are also included using placeholder syntax', async () => {
+		const redir = await fixture.readFile('/_redirects');
+		expect(redir).to.include('/pets/:cat       /pets/:cat/index.html        200');
+		expect(redir).to.include('/pets/:dog       /pets/:dog/index.html        200');
+		expect(redir).to.include('/pets            /.netlify/functions/entry    200');
 	});
 });
diff --git a/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[cat].astro b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[cat].astro
new file mode 100644
index 000000000..f86ee6ca9
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[cat].astro
@@ -0,0 +1,27 @@
+---
+export const prerender = true
+
+export function getStaticPaths() {
+  return [
+    {
+		params: {cat: 'cat1'},
+		props: {cat: 'cat1'}
+	},
+    {
+		params: {cat: 'cat2'},
+		props: {cat: 'cat2'}
+	},
+    {
+		params: {cat: 'cat3'},
+		props: {cat: 'cat3'}
+	},
+  ];
+}
+
+const { cat } = Astro.props;
+
+---
+
+<div>Good cat, {cat}!</div>
+
+<a href="/">back</a>
diff --git a/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[dog].astro b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[dog].astro
new file mode 100644
index 000000000..0f3300f04
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/[dog].astro
@@ -0,0 +1,27 @@
+---
+export const prerender = true
+
+export function getStaticPaths() {
+	return [
+    {
+		params: {dog: 'dog1'},
+		props: {dog: 'dog1'}
+	},
+    {
+		params: {dog: 'dog2'},
+		props: {dog: 'dog2'}
+	},
+    {
+		params: {dog: 'dog3'},
+		props: {dog: 'dog3'}
+	},
+  ];
+}
+
+const { dog } = Astro.props;
+
+---
+
+<div>Good dog, {dog}!</div>
+
+<a href="/">back</a>
diff --git a/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/index.astro b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/index.astro
new file mode 100644
index 000000000..d1423f8ef
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/dynamic-route/src/pages/pets/index.astro
@@ -0,0 +1,12 @@
+<html lang="en">
+	<head>
+		<meta charset="utf-8" />
+		<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+		<meta name="viewport" content="width=device-width" />
+		<meta name="generator" content={Astro.generator} />
+		<title>Astro</title>
+	</head>
+	<body>
+		<h1>Astro</h1>
+	</body>
+</html>
diff --git a/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/404.astro b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/404.astro
new file mode 100644
index 000000000..ad5d44aa2
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/404.astro
@@ -0,0 +1,8 @@
+<html>
+<head>
+	<title>Testing</title>
+</head>
+<body>
+	<h1>testing</h1>
+</body>
+</html>
diff --git a/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/index.astro b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/index.astro
new file mode 100644
index 000000000..ad5d44aa2
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/index.astro
@@ -0,0 +1,8 @@
+<html>
+<head>
+	<title>Testing</title>
+</head>
+<body>
+	<h1>testing</h1>
+</body>
+</html>
diff --git a/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/one.astro b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/one.astro
new file mode 100644
index 000000000..12146450e
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/prerender/src/pages/one.astro
@@ -0,0 +1,11 @@
+---
+export const prerender = true;
+---
+<html>
+<head>
+	<title>Testing</title>
+</head>
+<body>
+	<h1>testing</h1>
+</body>
+</html>
diff --git a/packages/integrations/netlify/test/functions/prerender.test.js b/packages/integrations/netlify/test/functions/prerender.test.js
new file mode 100644
index 000000000..324ebc5c5
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/prerender.test.js
@@ -0,0 +1,30 @@
+import { expect } from 'chai';
+import netlifyAdapter from '../../dist/index.js';
+import { loadFixture, testIntegration } from './test-utils.js';
+
+describe('Mixed Prerendering with SSR', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: new URL('./fixtures/prerender/', import.meta.url).toString(),
+			output: 'server',
+			adapter: netlifyAdapter({
+				dist: new URL('./fixtures/prerender/dist/', import.meta.url),
+			}),
+			site: `http://example.com`,
+			integrations: [testIntegration()],
+		});
+		await fixture.build();
+	});
+	it('Wildcard 404 is sorted last', async () => {
+		const redir = await fixture.readFile('/_redirects');
+		const baseRouteIndex = redir.indexOf('/       /.netlify/functions/entry    200');
+		const oneRouteIndex = redir.indexOf('/one    /one/index.html              200');
+		const fourOhFourWildCardIndex = redir.indexOf('/*      /.netlify/functions/entry    404');
+
+		expect(fourOhFourWildCardIndex).to.be.greaterThan(baseRouteIndex);
+		expect(fourOhFourWildCardIndex).to.be.greaterThan(oneRouteIndex);
+	});
+});