feat: add Next 13 request header mutation to middleware (#1866)

* test: add Next 13 request header mutation to middleware

* feat: support Next 13 request header mutation

* refactor: remove duplicate route conditional

* refactor: remove debugger

* test: update test to use Deno style of testing

include github workflow

* style: lint

* test: update test command

* refactor: remove debugger statement that snuck in

* fix: add the modified middleware headers to the request, not response

update the related tests

* style: lint

* fix: remove debugger

* test: move tests for request headers into standard

.github/workflows/test-deno.yml

@@ -0,0 +1,21 @@
+name: Deno tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Git Checkout Deno Module
+        uses: actions/checkout@v2
+      - name: Use Deno Version ${{ matrix.deno-version }}
+        uses: denolib/setup-deno@v2
+        with:
+          deno-version: vx.x.x
+      - name: Test Deno
+        run: deno test packages/runtime/src/templates/edge-shared/

cypress/integration/middleware/enhanced.spec.ts

@@ -1,16 +1,4 @@
 describe('Enhanced middleware', () => {
-  it('adds request headers', () => {
-    cy.request('/api/hello').then((response) => {
-      expect(response.body).to.have.nested.property('headers.x-hello', 'world')
-    })
-  })
-
-  it('adds request headers to a rewrite', () => {
-    cy.request('/headers').then((response) => {
-      expect(response.body).to.have.nested.property('headers.x-hello', 'world')
-    })
-  })
-
   it('rewrites the response body', () => {
     cy.visit('/static')
     cy.get('#message').contains('This was static but has been transformed in')

cypress/integration/middleware/standard.spec.ts

@@ -1,4 +1,16 @@
 describe('Standard middleware', () => {
+  it('adds request headers', () => {
+    cy.request('/api/hello').then((response) => {
+      expect(response.body).to.have.nested.property('headers.x-hello', 'world')
+    })
+  })
+
+  it('adds request headers to a rewrite', () => {
+    cy.request('/headers').then((response) => {
+      expect(response.body).to.have.nested.property('headers.x-hello', 'world')
+    })
+  })
+
   it('rewrites to internal page', () => {
     // preview mode is off by default
     cy.visit('/shows/rewriteme')

demos/middleware/middleware.ts

@@ -8,6 +8,18 @@ export async function middleware(req: NextRequest) {
   let response
   const { pathname } = req.nextUrl
 
+  if (pathname.startsWith('/api/hello')) {
+    // Next 13 request header mutation functionality
+    const headers = new Headers(req.headers)
+
+    headers.set('x-hello', 'world')
+    return NextResponse.next({
+      request: {
+        headers
+      }
+    })
+  }
+
   const request = new MiddlewareRequest(req)
   if (pathname.startsWith('/static')) {
     // Unlike NextResponse.next(), this actually sends the request to the origin
@@ -24,12 +36,6 @@ export async function middleware(req: NextRequest) {
     return res
   }
 
-  if (pathname.startsWith('/api/hello')) {
-    // Add a header to the request
-    req.headers.set('x-hello', 'world')
-    return request.next()
-  }
-
   if (pathname.startsWith('/api/geo')) {
     req.headers.set('x-geo-country', req.geo.country)
     req.headers.set('x-geo-region', req.geo.region)

package.json

@@ -18,6 +18,7 @@
     "postinstall": "run-s build install-husky",
     "install-husky": "if-env CI=1 || husky install node_modules/@netlify/eslint-config-node/.husky",
     "test": "run-s build:demo test:jest",
+    "test:deno": "deno test packages/runtime/src/templates/edge-shared/",
     "test:next": "jest -c test/e2e/jest.config.js",
     "test:next:disabled": "RUN_SKIPPED_TESTS=1 jest -c test/e2e/jest.config.disabled.js",
     "test:next:all": "RUN_SKIPPED_TESTS=1 jest -c test/e2e/jest.config.all.js",
@@ -101,7 +102,8 @@
       "**/test/**/*.spec.ts",
       "!**/test/e2e/**",
       "!**/test/fixtures/**",
-      "!**/test/sample/**"
+      "!**/test/sample/**",
+      "!**/test/templates/edge-shared/**"
     ],
     "transform": {
       "\\.[jt]sx?$": "babel-jest"