Netlify Edge function support (#3148)

* Netlify Edge function support

* Update readme with edge function information

* Adds a changeset

* Disable running edge function test in CI for now

1 files changed, 98 insertions, 0 deletions

diff --git a/packages/integrations/netlify/src/integration-edge-functions.ts b/packages/integrations/netlify/src/integration-edge-functions.ts
new file mode 100644
index 000000000..fcce820f4
--- /dev/null
+++ b/packages/integrations/netlify/src/integration-edge-functions.ts
@@ -0,0 +1,98 @@
+import type { AstroAdapter, AstroIntegration, AstroConfig, RouteData } from 'astro';
+import * as fs from 'fs';
+
+export function getAdapter(): AstroAdapter {
+	return {
+		name: '@astrojs/netlify/edge-functions',
+		serverEntrypoint: '@astrojs/netlify/netlify-edge-functions.js',
+		exports: ['default'],
+	};
+}
+
+interface NetlifyEdgeFunctionsOptions {
+	dist?: URL;
+}
+
+interface NetlifyEdgeFunctionManifestFunctionPath {
+	function: string;
+	path: string;
+}
+
+interface NetlifyEdgeFunctionManifestFunctionPattern {
+	function: string;
+	pattern: string;
+}
+
+type NetlifyEdgeFunctionManifestFunction = NetlifyEdgeFunctionManifestFunctionPath | NetlifyEdgeFunctionManifestFunctionPattern;
+
+interface NetlifyEdgeFunctionManifest {
+	functions: NetlifyEdgeFunctionManifestFunction[];
+	version: 1;
+}
+
+async function createEdgeManifest(routes: RouteData[], entryFile: string, dir: URL) {
+	const functions: NetlifyEdgeFunctionManifestFunction[] = [];
+				for(const route of routes) {
+					if(route.pathname) {
+						functions.push({
+							function: entryFile,
+							path: route.pathname
+						});
+					} else {
+						functions.push({
+							function: entryFile,
+							pattern: route.pattern.source
+						});
+					}
+				}
+
+				const manifest: NetlifyEdgeFunctionManifest = {
+					functions,
+					version: 1
+				};
+
+				const manifestURL = new URL('./manifest.json', dir);
+				const _manifest = JSON.stringify(manifest, null, '  ');
+				await fs.promises.writeFile(manifestURL, _manifest, 'utf-8');
+}
+
+export function netlifyEdgeFunctions({ dist }: NetlifyEdgeFunctionsOptions = {}): AstroIntegration {
+	let _config: AstroConfig;
+	let entryFile: string;
+	return {
+		name: '@astrojs/netlify/edge-functions',
+		hooks: {
+			'astro:config:setup': ({ config }) => {
+				if (dist) {
+					config.outDir = dist;
+				} else {
+					config.outDir = new URL('./netlify/', config.root);
+				}
+			},
+			'astro:config:done': ({ config, setAdapter }) => {
+				setAdapter(getAdapter());
+				_config = config;
+			},
+			'astro:build:start': async ({ buildConfig }) => {
+				entryFile = buildConfig.serverEntry.replace(/\.m?js/, '');
+				buildConfig.client = _config.outDir;
+				buildConfig.server = new URL('./edge-functions/', _config.outDir);
+			},
+			'astro:build:setup': ({ vite, target }) => {
+				if (target === 'server') {
+					vite.ssr = {
+						noExternal: true,
+					};
+				}
+			},
+			'astro:build:done': async ({ routes, dir }) => {
+				
+				await createEdgeManifest(routes, entryFile, new URL('./edge-functions/', dir));
+			},
+		},
+	};
+}
+
+export {
+	netlifyEdgeFunctions as default
+}