feat: support after()

.github/workflows/pre-release.yml

@@ -23,8 +23,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/e55f825bd985d3c92e21d1b765d71e70d5628fba/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
       - name: Extract tag and version
         id: extract
         run: |-

.github/workflows/release-please.yml

@@ -31,8 +31,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/e55f825bd985d3c92e21d1b765d71e70d5628fba/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
       - name: Build
         run: npm run build
         if: ${{ steps.release.outputs.release_created }}

.github/workflows/run-tests.yml

@@ -65,8 +65,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/main/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
       - name: 'Install dependencies'
         run: npm ci
       - name: 'Prepare Netlify CLI'
@@ -134,7 +134,7 @@ jobs:
         uses: denoland/setup-deno@v1
         with:
           # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/e55f825bd985d3c92e21d1b765d71e70d5628fba/node/bridge.ts#L17
-          deno-version: v1.37.0
+          deno-version: v1.44.4
       - name: 'Install dependencies'
         run: npm ci
       - name: 'Build'
@@ -198,8 +198,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/main/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
       - name: 'Install dependencies'
         run: npm ci
       - name: 'Build'

.github/workflows/size-check.yml

@@ -23,8 +23,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/main/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
       - run: npm ci
 
       - name: Package size report

.github/workflows/test-e2e.yml

@@ -161,8 +161,8 @@ jobs:
       - name: Install Deno
         uses: denoland/setup-deno@v1
         with:
-          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/edge-bundler/blob/main/node/bridge.ts#L17
-          deno-version: v1.37.0
+          # Should match the `DENO_VERSION_RANGE` from https://github.com/netlify/build/blob/main/packages/edge-bundler/node/bridge.ts#L20
+          deno-version: v1.44.4
 
       - name: install runtime
         run: npm install --ignore-scripts

src/build/templates/handler-monorepo.tmpl.js

@@ -16,7 +16,7 @@ export default async function (req, context) {
     tracing.start()
   }
 
-  const requestContext = createRequestContext(req)
+  const requestContext = createRequestContext(req, context)
   const tracer = getTracer()
 
   const handlerResponse = await runWithRequestContext(requestContext, () => {

src/build/templates/handler.tmpl.js

@@ -13,7 +13,7 @@ export default async function handler(req, context) {
   if (process.env.NETLIFY_OTLP_TRACE_EXPORTER_URL) {
     tracing.start()
   }
-  const requestContext = createRequestContext(req)
+  const requestContext = createRequestContext(req, context)
   const tracer = getTracer()
 
   const handlerResponse = await runWithRequestContext(requestContext, () => {

src/run/handlers/request-context.cts

@@ -1,11 +1,18 @@
 import { AsyncLocalStorage } from 'node:async_hooks'
 
+import type { Context } from '@netlify/functions'
 import { LogLevel, systemLogger } from '@netlify/functions/internal'
 
 import type { NetlifyCachedRouteValue } from '../../shared/cache-types.cjs'
 
 type SystemLogger = typeof systemLogger
 
+// TODO: remove once https://github.com/netlify/serverless-functions-api/pull/219
+// is released and public types are updated
+export interface FutureContext extends Context {
+  waitUntil?: (promise: Promise<unknown>) => void
+}
+
 export type RequestContext = {
   captureServerTiming: boolean
   responseCacheGetLastModified?: number
@@ -28,13 +35,17 @@ export type RequestContext = {
 
 type RequestContextAsyncLocalStorage = AsyncLocalStorage<RequestContext>
 
-export function createRequestContext(request?: Request): RequestContext {
+export function createRequestContext(request?: Request, context?: FutureContext): RequestContext {
   const backgroundWorkPromises: Promise<unknown>[] = []
 
   return {
     captureServerTiming: request?.headers.has('x-next-debug-logging') ?? false,
     trackBackgroundWork: (promise) => {
-      backgroundWorkPromises.push(promise)
+      if (context?.waitUntil) {
+        context.waitUntil(promise)
+      } else {
+        backgroundWorkPromises.push(promise)
+      }
     },
     get backgroundWorkPromise() {
       return Promise.allSettled(backgroundWorkPromises)

src/run/handlers/server.ts

@@ -1,7 +1,6 @@
 import type { OutgoingHttpHeaders } from 'http'
 
 import { ComputeJsOutgoingMessage, toComputeResponse, toReqRes } from '@fastly/http-compute-js'
-import { Context } from '@netlify/functions'
 import type { NextConfigComplete } from 'next/dist/server/config-shared.js'
 import type { WorkerRequestHandler } from 'next/dist/server/lib/types.js'
 
@@ -16,9 +15,12 @@ import { nextResponseProxy } from '../revalidate.js'
 
 import { createRequestContext, getLogger, getRequestContext } from './request-context.cjs'
 import { getTracer } from './tracer.cjs'
+import { setupWaitUntil } from './wait-until.cjs'
 
 const nextImportPromise = import('../next.cjs')
 
+setupWaitUntil()
+
 let nextHandler: WorkerRequestHandler, nextConfig: NextConfigComplete
 
 /**
@@ -44,13 +46,7 @@ const disableFaultyTransferEncodingHandling = (res: ComputeJsOutgoingMessage) =>
   }
 }
 
-// TODO: remove once https://github.com/netlify/serverless-functions-api/pull/219
-// is released and public types are updated
-interface FutureContext extends Context {
-  waitUntil?: (promise: Promise<unknown>) => void
-}
-
-export default async (request: Request, context: FutureContext) => {
+export default async (request: Request) => {
   const tracer = getTracer()
 
   if (!nextHandler) {
@@ -128,19 +124,19 @@ export default async (request: Request, context: FutureContext) => {
       return new Response(body || null, response)
     }
 
-    if (context.waitUntil) {
-      context.waitUntil(requestContext.backgroundWorkPromise)
-    }
-
     const keepOpenUntilNextFullyRendered = new TransformStream({
       async flush() {
         // it's important to keep the stream open until the next handler has finished
         await nextHandlerPromise
-        if (!context.waitUntil) {
-          // if waitUntil is not available, we have to keep response stream open until background promises are resolved
-          // to ensure that all background work executes
-          await requestContext.backgroundWorkPromise
-        }
+
+        // Next.js relies on `close` event emitted by response to trigger running callback variant of `next/after`
+        // however @fastly/http-compute-js never actually emits that event - so we have to emit it ourselves,
+        // otherwise Next would never run the callback variant of `next/after`
+        res.emit('close')
+
+        // if waitUntil is not available, we have to keep response stream open until background promises are resolved
+        // to ensure that all background work executes
+        await requestContext.backgroundWorkPromise
       },
     })
 

src/run/handlers/wait-until.cts

@@ -0,0 +1,26 @@
+import { getRequestContext } from './request-context.cjs'
+
+/**
+ *  @see https://github.com/vercel/next.js/blob/canary/packages/next/src/server/after/builtin-request-context.ts
+ */
+const NEXT_REQUEST_CONTEXT_SYMBOL = Symbol.for('@next/request-context')
+
+export type NextJsRequestContext = {
+  get(): { waitUntil?: (promise: Promise<unknown>) => void } | undefined
+}
+
+type GlobalThisWithRequestContext = typeof globalThis & {
+  [NEXT_REQUEST_CONTEXT_SYMBOL]?: NextJsRequestContext
+}
+
+/**
+ * Registers a `waitUntil` to be used by Next.js for next/after
+ */
+export function setupWaitUntil() {
+  // eslint-disable-next-line @typescript-eslint/no-extra-semi
+  ;(globalThis as GlobalThisWithRequestContext)[NEXT_REQUEST_CONTEXT_SYMBOL] = {
+    get() {
+      return { waitUntil: getRequestContext()?.trackBackgroundWork }
+    },
+  }
+}

tests/e2e/simple-app.test.ts

@@ -272,3 +272,42 @@ test('can require CJS module that is not bundled', async ({ simple }) => {
   expect(parsedBody.notBundledCJSModule.isBundled).toEqual(false)
   expect(parsedBody.bundledCJSModule.isBundled).toEqual(true)
 })
+
+test('next/after callback is executed and finishes', async ({ page, simple }) => {
+  test.skip(!nextVersionSatisfies('>=15.0.0'), 'This test is only for Next.js 15+')
+
+  // trigger initial request to check page which might be stale and allow regenerating in background
+  await page.goto(`${simple.url}/after/check`)
+
+  await new Promise((resolve) => setTimeout(resolve, 5000))
+
+  // after it was possibly regenerated we can start checking actual content of the page
+  await page.goto(`${simple.url}/after/check`)
+  const pageInfoLocator1 = await page.locator('#page-info')
+  const pageInfo1 = JSON.parse((await pageInfoLocator1.textContent()) ?? '{}')
+
+  expect(typeof pageInfo1?.timestamp, 'Check page should have timestamp').toBe('number')
+
+  await page.goto(`${simple.url}/after/check`)
+  const pageInfoLocator2 = await page.locator('#page-info')
+  const pageInfo2 = JSON.parse((await pageInfoLocator2.textContent()) ?? '{}')
+
+  expect(typeof pageInfo2?.timestamp, 'Check page should have timestamp').toBe('number')
+
+  expect(pageInfo2.timestamp, 'Check page should be cached').toBe(pageInfo1.timestamp)
+
+  await page.goto(`${simple.url}/after/trigger`)
+
+  // wait for next/after to trigger revalidation of check page
+  await new Promise((resolve) => setTimeout(resolve, 5000))
+
+  await page.goto(`${simple.url}/after/check`)
+  const pageInfoLocator3 = await page.locator('#page-info')
+  const pageInfo3 = JSON.parse((await pageInfoLocator3.textContent()) ?? '{}')
+
+  expect(typeof pageInfo3?.timestamp, 'Check page should have timestamp').toBe('number')
+  expect(
+    pageInfo3.timestamp,
+    'Check page should be invalidated with newer timestamp',
+  ).toBeGreaterThan(pageInfo1.timestamp)
+})

tests/fixtures/simple/app/after/check/page.js

@@ -0,0 +1,10 @@
+export const revalidate = 3600 // arbitrarily long, just so that it doesn't happen during a test run
+
+export default async function Page() {
+  const data = {
+    timestamp: Date.now(),
+  }
+  console.log('/timestamp/key/[key] rendered', data)
+
+  return <div id="page-info">{JSON.stringify(data)}</div>
+}

tests/fixtures/simple/app/after/trigger/page.js

@@ -0,0 +1,17 @@
+import { revalidatePath } from 'next/cache'
+import { unstable_after as after, connection } from 'next/server'
+
+export default async function Page() {
+  await connection()
+  after(async () => {
+    // this will run after response was sent
+    console.log('after() triggered')
+    console.log('after() sleep 1s')
+    await new Promise((resolve) => setTimeout(resolve, 1000))
+
+    console.log('after() revalidatePath /after/check')
+    revalidatePath('/after/check')
+  })
+
+  return <div>Page with after()</div>
+}

tests/fixtures/simple/next.config.js

@@ -8,6 +8,7 @@ const nextConfig = {
     outputFileTracingIncludes: {
       '/': ['public/**'],
     },
+    after: true,
   },
   images: {
     remotePatterns: [

tests/integration/simple-app.test.ts

@@ -58,6 +58,7 @@ test<FixtureTestContext>('Test that the simple next app is working', async (ctx)
   const blobEntries = await getBlobEntries(ctx)
   expect(blobEntries.map(({ key }) => decodeBlobKey(key)).sort()).toEqual([
     '/404',
+    '/after/check',
     '/api/cached-permanent',
     '/api/cached-revalidate',
     '/image/local',

tests/smoke/deploy.test.ts

@@ -71,9 +71,13 @@ describe('version check', () => {
       )
     },
   )
-  test('yarn monorepo multiple next versions site is compatible', { retry: 0 }, async () => {
-    await smokeTest(selfCleaningFixtureFactories.yarnMonorepoMultipleNextVersionsSiteCompatible)
-  })
+  test(
+    'yarn monorepo multiple next versions site is compatible',
+    { retry: 0, timeout: 1_000 * 60 * 5 },
+    async () => {
+      await smokeTest(selfCleaningFixtureFactories.yarnMonorepoMultipleNextVersionsSiteCompatible)
+    },
+  )
 
   test(
     'yarn monorepo multiple next versions site is incompatible should not deploy',