feat: vercel-edge provider (#337)

docs/deploy/providers/vercel.md

@@ -17,3 +17,16 @@ After your project has been imported and deployed, all subsequent pushes to bran
 
 Learn more about Vercel’s [Git Integration](https://vercel.com/docs/concepts/git).
 
+## Vercel Edge Functions
+
+**Preset:** `vercel-edge` ([switch to this preset](/deploy/#changing-the-deployment-preset))
+
+It is possible to deploy your nitro applications directly on [Vercel Edge Functions](https://vercel.com/docs/concepts/functions/edge-functions).
+
+> Vercel Edge Functions allow you to deliver content to your site's visitors with speed and personalization.
+> They are deployed globally by default on Vercel's Edge Network and enable you to move server-side logic to the Edge, close to your visitor's origin.
+> Edge Functions use the Vercel Edge Runtime, which is built on the same high-performance V8 JavaScript and WebAssembly engine that is used by the Chrome browser.
+> By taking advantage of this small runtime, Edge Functions can have faster cold boots and higher scalability than Serverless Functions.
+> Edge Functions run after the cache, and can both cache and return responses. [Read More](https://vercel.com/docs/concepts/functions/edge-functions)
+
+In oerder to enable this target, please set `NITRO_PRESET` environment variable to `vercel-edge`.

package.json

@@ -110,6 +110,7 @@
     "@types/semver": "^7.3.10",
     "@types/serve-static": "^1.13.10",
     "c8": "^7.11.3",
+    "edge-runtime": "1.1.0-beta.11",
     "eslint": "^8.19.0",
     "execa": "^6.1.0",
     "miniflare": "^2.6.0",

src/presets/vercel.ts

@@ -52,3 +52,49 @@ export const vercel = defineNitroPreset({
     }
   }
 })
+
+export const vercelEdge = defineNitroPreset({
+  extends: 'base-worker',
+  entry: '#internal/nitro/entries/vercel-edge',
+  output: {
+    dir: '{{ rootDir }}/.vercel/output',
+    serverDir: '{{ output.dir }}/functions/index.func',
+    publicDir: '{{ output.dir }}/static'
+  },
+  commands: {
+    deploy: '',
+    preview: 'npx edge-runtime ./functions/index.func/index.mjs --listen'
+  },
+  hooks: {
+    async 'compiled' (nitro: Nitro) {
+      const buildConfigPath = resolve(nitro.options.output.dir, 'config.json')
+      const buildConfig = {
+        version: '3',
+        routes: [
+          ...nitro.options.publicAssets
+            .filter(asset => !asset.fallthrough)
+            .map(asset => asset.baseURL)
+            .map(baseURL => ({
+              src: baseURL + '(.*)',
+              headers: {
+                'cache-control': 'public,max-age=31536000,immutable'
+              },
+              continue: true
+            })),
+          {
+            src: '/(.*)',
+            dest: '/'
+          }
+        ]
+      }
+      await writeFile(buildConfigPath, JSON.stringify(buildConfig, null, 2))
+
+      const functionConfigPath = resolve(nitro.options.output.serverDir, '.vc-config.json')
+      const functionConfig = {
+        runtime: 'edge',
+        entrypoint: 'index.mjs'
+      }
+      await writeFile(functionConfigPath, JSON.stringify(functionConfig, null, 2))
+    }
+  }
+})

src/runtime/entries/vercel-edge.ts

@@ -0,0 +1,36 @@
+import '#internal/nitro/virtual/polyfill'
+import { requestHasBody, useRequestBody } from '#internal/nitro/utils'
+import { nitroApp } from '#internal/nitro/app'
+
+addEventListener('fetch', (event: any) => {
+  event.respondWith(handleEvent(event))
+})
+
+async function handleEvent (event) {
+  const url = new URL(event.request.url)
+  let body
+  if (requestHasBody(event.request)) {
+    body = await useRequestBody(event.request)
+  }
+
+  const r = await nitroApp.localCall({
+    event,
+    url: url.pathname + url.search,
+    host: url.hostname,
+    protocol: url.protocol,
+    headers: Object.fromEntries(event.request.headers.entries()),
+    method: event.request.method,
+    redirect: event.request.redirect,
+    body
+  })
+
+  return new Response(r.body, {
+    headers: normalizeOutgoingHeaders(r.headers),
+    status: r.status,
+    statusText: r.statusText
+  })
+}
+
+function normalizeOutgoingHeaders (headers: Record<string, string | string[] | undefined>) {
+  return Object.entries(headers).map(([k, v]) => [k, Array.isArray(v) ? v.join(',') : v])
+}

test/presets/vercel.test.ts

@@ -1,5 +1,7 @@
+import { promises as fsp } from 'fs'
 import { resolve } from 'pathe'
 import { describe } from 'vitest'
+import { EdgeRuntime } from 'edge-runtime'
 import { setupTest, startServer, testNitro } from '../tests'
 
 describe('nitro:preset:vercel', async () => {
@@ -14,3 +16,16 @@ describe('nitro:preset:vercel', async () => {
     }
   })
 })
+
+describe('nitro:preset:vercel-edge', async () => {
+  const ctx = await setupTest('vercel-edge')
+  testNitro(ctx, async () => {
+    const entry = resolve(ctx.outDir, 'functions/index.func/index.mjs')
+    const entryCode = await fsp.readFile(entry, 'utf8')
+    const runtime = new EdgeRuntime({ initialCode: entryCode })
+    return async ({ url }) => {
+      const res = await runtime.dispatchFetch('http://localhost' + url)
+      return res
+    }
+  })
+})

test/tests.ts

@@ -32,7 +32,7 @@ export async function setupTest (preset) {
   const nitro = ctx.nitro = await createNitro({
     preset: ctx.preset,
     rootDir: ctx.rootDir,
-    serveStatic: preset !== 'cloudflare',
+    serveStatic: preset !== 'cloudflare' && preset !== 'vercel-edge',
     output: { dir: ctx.outDir }
   })
   await prepare(nitro)