fix: don't ever execute middleware in lambda (#2249)

* test: add test for preview mode when using middleware * fix: skip ever trying to run middleware in lambda --------- Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Author: pieh

cypress/e2e/middleware/preview.cy.ts

@@ -0,0 +1,34 @@
+describe('Preview Mode', () => {
+ it('enters and exits preview mode', () => {
+ Cypress.Cookies.debug(true)
+ cy.getCookies().then((cookie) => cy.log('cookies', cookie))
+
+ cy.intercept('/previewTest', (req) => {
+ req.continue((res) => {
+ expect(res.headers?.['x-middleware-executed']).to.equal('true')
+ })
+ }).as('previewTestVisit')
+
+ // preview mode is off by default
+ cy.visit('/previewTest')
+ cy.findByText('Is preview? No', { selector: 'h1' })
+
+ // enter preview mode
+ cy.request('/api/enterPreview').then((response) => {
+ expect(response.body).to.have.property('name', 'preview mode')
+ })
+
+ // exptected content is rendered
+ cy.visit('/previewTest')
+ cy.findByText('Is preview? Yes!', { selector: 'h1' })
+
+ // exit preview mode
+ cy.request('/api/exitPreview')
+ cy.visit('/previewTest')
+ cy.findByText('Is preview? No', { selector: 'h1' })
+
+ // we should hit /previewTest 3 times (before entering preview, after entering preview, after exiting preview)
+ // this assertion is mainly to ensure interception works and assertion on response header is made
+ cy.get('@previewTestVisit.all').should('have.length', 3)
+ })
+})

demos/middleware/middleware.ts

@@ -15,11 +15,11 @@ export async function middleware(req: NextRequest) {
  headers.set('x-hello', 'world')
  return NextResponse.next({
  request: {
- headers
- }
+ headers,
+ },
  })
  }
- 
+
  const request = new MiddlewareRequest(req)
 
  // skipMiddlewareUrlNormalize next config option is used so we have to try to match both html path and data blob path
@@ -41,12 +41,11 @@ export async function middleware(req: NextRequest) {
  // skipMiddlewareUrlNormalize next config option is used so we have to try to match both html path and data blob path
  if (pathname.startsWith('/request-rewrite') || pathname.endsWith('/request-rewrite.json')) {
  // request.rewrite() should return the MiddlewareResponse object instead of the Response object.
- const res = await request.rewrite('/static-rewrite',
- {
+ const res = await request.rewrite('/static-rewrite', {
  headers: {
  'x-rewrite-test': 'hello',
- 'x-rewrite-test-2': 'hello-2'
- }
+ 'x-rewrite-test-2': 'hello-2',
+ },
  })
  const message = `This was static (& escaping test &) but has been transformed in ${req.geo?.city}`
 
@@ -90,7 +89,7 @@ export async function middleware(req: NextRequest) {
  return response
  }
 
- if(pathname.startsWith('/matcher-cookie')) {
+ if (pathname.startsWith('/matcher-cookie')) {
  response = NextResponse.next()
  response.cookies.set('missingCookie', 'true')
  return response
@@ -109,6 +108,13 @@ export async function middleware(req: NextRequest) {
  return response
  }
 
+ if (pathname.startsWith('/previewTest')) {
+ response = NextResponse.next()
+
+ response.headers.set('x-middleware-executed', 'true')
+ return response
+ }
+
  if (pathname.includes('locale-preserving-rewrite')) {
  return NextResponse.rewrite(new URL('/locale-test', req.url))
  }
@@ -167,8 +173,8 @@ export const config = {
  '/:all*/locale-preserving-rewrite',
  '/cookies/:path*',
  { source: '/static' },
- {source: '/request-rewrite' },
- { source: '/matcher-cookie'},
+ { source: '/request-rewrite' },
+ { source: '/matcher-cookie' },
  { source: '/shows/((?!99|88).*)' },
  {
  source: '/conditional',
@@ -186,8 +192,9 @@ export const config = {
  {
  type: 'cookie',
  key: 'missingCookie',
- }
+ },
  ],
  },
+ '/previewTest',
  ],
 }

demos/middleware/pages/api/enterPreview.js

@@ -0,0 +1,6 @@
+export default async function preview(req, res) {
+ // Enable Preview Mode by setting the cookies
+ res.setPreviewData({})
+
+ res.status(200).json({ name: 'preview mode' })
+}

demos/middleware/pages/api/exitPreview.js

@@ -0,0 +1,8 @@
+export default async function exit(_, res) {
+ // Exit the current user from "Preview Mode". This function accepts no args.
+ res.clearPreviewData()
+
+ // Redirect the user back to the index page.
+ res.writeHead(307, { Location: '/' })
+ res.end()
+}

demos/middleware/pages/index.js

@@ -48,6 +48,9 @@ export default function Home() {
  <p>
  <Link href="/headers">Adds `x-hello` request header to a rewrite</Link>
  </p>
+ <p>
+ <Link href="/previewTest">Preview mode</Link>
+ </p>
  </main>
  </div>
  )

demos/middleware/pages/previewTest.js

@@ -0,0 +1,25 @@
+import Link from 'next/link'
+
+const StaticTest = ({ isPreview }) => {
+ return (
+ <div>
+ <h1>Is preview? {isPreview ? 'Yes!' : 'No'}</h1>
+ <p>
+ <a href={isPreview ? '/api/exitPreview' : '/api/enterPreview'}>
+ {isPreview ? 'Exit Preview' : 'Enter Preview'}
+ </a>
+ </p>
+ <Link href="/">Go back home</Link>
+ </div>
+ )
+}
+
+export const getStaticProps = async ({ preview }) => {
+ return {
+ props: {
+ isPreview: Boolean(preview),
+ },
+ }
+}
+
+export default StaticTest

packages/runtime/src/templates/server.ts

@@ -18,6 +18,7 @@ interface NetlifyConfig {
  revalidateToken?: string
 }
 
+// eslint-disable-next-line max-lines-per-function
 const getNetlifyNextServer = (NextServer: NextServerType) => {
  class NetlifyNextServer extends NextServer {
  private netlifyConfig: NetlifyConfig
@@ -118,6 +119,13 @@ const getNetlifyNextServer = (NextServer: NextServerType) => {
  }
  }
 
+ // eslint-disable-next-line class-methods-use-this, require-await
+ async runMiddleware(): Promise<{ finished: boolean }> {
+ return {
+ finished: false,
+ }
+ }
+
  private getNetlifyPathsForRoute(route: string): string[] {
  const { i18n } = this.nextConfig
  const { routes, dynamicRoutes } = this.netlifyPrerenderManifest