feat: add support for Next 12.3 middleware matchers (#1612)

* feat: add support for Next 12.3 middleware matchers

* fix: support legacy experimental config

* chore: make canary use old version

* feat: support middleware `has` matchers

* chore: make canary use old version

* chore: add test middleware

* chore: add e2e tests

* fix: handle json headers

Author: ascorbic

.eslintignore

@@ -4,5 +4,6 @@ test
 lib
 demos
 packages/runtime/src/templates/edge
+packages/runtime/src/templates/edge-shared
 packages/runtime/lib
 packages/runtime/dist-types

.vscode/settings.json

@@ -1,6 +1,7 @@
 {
   "deno.enablePaths": [
     "packages/runtime/src/templates/edge",
+    "packages/runtime/src/templates/edge-shared",
     "demos/middleware/.netlify/edge-functions",
     "demos/server-components/.netlify/edge-functions",
   ],

cypress/integration/middleware/standard.spec.ts

@@ -20,3 +20,26 @@ describe('Standard middleware', () => {
     })
   })
 })
+
+describe('Middleware matchers', () => {
+  it('does not apply "has" matcher when headers are not sent', () => {
+    cy.request('/conditional').then((response) => {
+      expect(response.headers).not.to.have.property('x-is-deno', 'true')
+      expect(response.headers).not.to.have.property('x-modified-edge', 'true')
+    })
+  })
+
+  it('matches when headers are sent', () => {
+    cy.request({ url: '/conditional', headers: { 'x-my-header': 'my-value' } }).then((response) => {
+      expect(response.headers).to.have.property('x-is-deno', 'true')
+      expect(response.headers).to.have.property('x-modified-edge', 'true')
+    })
+  })
+
+  it('matches when headers are sent', () => {
+    cy.request('/_next/data/build-id/static.json').then((response) => {
+      expect(response.headers).to.have.property('x-is-deno', 'true')
+      expect(response.headers).to.have.property('x-modified-edge', 'true')
+    })
+  })
+})

demos/base-path/package.json

@@ -13,7 +13,7 @@
     "typescript": "^4.6.3"
   },
   "dependencies": {
-    "next": "^12.2.0"
+    "next": "^12.3.0"
   },
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"

demos/canary/middleware.ts

@@ -0,0 +1,13 @@
+import { NextResponse } from 'next/server'
+import type { NextRequest } from 'next/server'
+
+export async function middleware(req: NextRequest) {
+  const res = NextResponse.rewrite(new URL('/', req.url))
+  res.headers.set('x-response-header', 'set in middleware')
+  res.headers.set('x-is-deno', 'Deno' in globalThis ? 'true' : 'false')
+  return res
+}
+
+export const config = {
+  matcher: ['/foo'],
+}