Custom App Hosting Headers for NextJS

packages/@apphosting/adapter-nextjs/e2e/app.spec.ts

@@ -1,8 +1,18 @@
 import * as assert from "assert";
 import { posix } from "path";
+import fsExtra from "fs-extra";
 
 export const host = process.env.HOST;
 
+const { readJson } = fsExtra;
+let adapterVersion: string;
+
+before(async () => {
+  const packageJson = await readJson("package.json");
+  adapterVersion = packageJson.version;
+  if (!adapterVersion) throw new Error("couldn't parse package.json version");
+});
+
 if (!host) {
   throw new Error("HOST environment variable expected");
 }
@@ -114,4 +124,30 @@ describe("app", () => {
       "private, no-cache, no-store, max-age=0, must-revalidate",
     );
   });
+
+  it("should have x-fah-adapter header and no x-fah-middleware header on all routes", async () => {
+    const routes = [
+      "/",
+      "/ssg",
+      "/ssr",
+      "/ssr/streaming",
+      "/isr/time",
+      "/isr/demand",
+      "/nonexistent-route",
+    ];
+
+    for (const route of routes) {
+      const response = await fetch(posix.join(host, route));
+      assert.equal(
+        response.headers.get("x-fah-adapter"),
+        `nextjs-${adapterVersion}`,
+        `Route ${route} missing x-fah-adapter header`,
+      );
+      assert.equal(
+        response.headers.get("x-fah-middleware"),
+        null,
+        `Route ${route} should not have x-fah-middleware header`,
+      );
+    }
+  });
 });

packages/@apphosting/adapter-nextjs/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@apphosting/adapter-nextjs",
-  "version": "14.0.9",
+  "version": "14.0.10",
   "main": "dist/index.js",
   "description": "Experimental addon to the Firebase CLI to add web framework support",
   "repository": {
@@ -23,7 +23,7 @@
   "scripts": {
     "build": "rm -rf dist && tsc && chmod +x ./dist/bin/*",
     "test": "npm run test:unit && npm run test:functional",
-    "test:unit": "ts-mocha -p tsconfig.json src/**/*.spec.ts",
+    "test:unit": "ts-mocha -p tsconfig.json 'src/**/*.spec.ts' 'src/*.spec.ts'",
     "test:functional": "node --loader ts-node/esm ./e2e/run-local.ts",
     "localregistry:start": "npx verdaccio --config ../publish-dev/verdaccio-config.yaml",
     "localregistry:publish": "(npm view --registry=http://localhost:4873 @apphosting/adapter-nextjs && npm unpublish --@apphosting:registry=http://localhost:4873 --force); npm publish --@apphosting:registry=http://localhost:4873"

packages/@apphosting/adapter-nextjs/src/bin/build.spec.ts

@@ -24,24 +24,25 @@ describe("build commands", () => {
   });
 
   it("expects all output bundle files to be generated", async () => {
-    const { generateBuildOutput, validateOutputDirectory, createMetadata } = await importUtils;
+    const { generateBuildOutput, validateOutputDirectory, getAdapterMetadata } = await importUtils;
     const files = {
       ".next/standalone/server.js": "",
       ".next/static/staticfile": "",
       ".next/routes-manifest.json": `{
-        "headers":[], 
-        "rewrites":[], 
+        "headers":[],
+        "rewrites":[],
         "redirects":[]
       }`,
     };
-    const packageVersion = createMetadata(defaultNextVersion).adapterVersion;
+    const adapterMetadata = getAdapterMetadata();
     generateTestFiles(tmpDir, files);
     await generateBuildOutput(
       tmpDir,
       tmpDir,
       outputBundleOptions,
       path.join(tmpDir, ".next"),
       defaultNextVersion,
+      adapterMetadata,
     );
     await validateOutputDirectory(outputBundleOptions, path.join(tmpDir, ".next"));
 
@@ -53,7 +54,7 @@ runConfig:
   runCommand: node .next/standalone/server.js
 metadata:
   adapterPackageName: "@apphosting/adapter-nextjs"
-  adapterVersion: ${packageVersion}
+  adapterVersion: ${adapterMetadata.adapterVersion}
   framework: nextjs
   frameworkVersion: ${defaultNextVersion}
 `,
@@ -97,6 +98,10 @@ metadata:
       },
       path.join(tmpDir, ".next"),
       defaultNextVersion,
+      {
+        adapterPackageName: "@apphosting/adapter-nextjs",
+        adapterVersion: "14.0.1",
+      },
     );
 
     const expectedFiles = {
@@ -117,8 +122,8 @@ metadata:
       ".next/standalone/notserver.js": "",
       ".next/static/staticfile": "",
       ".next/routes-manifest.json": `{
-        "headers":[{"source":"source", "headers":["header1"]}], 
-        "rewrites":[{"source":"source", "destination":"destination"}], 
+        "headers":[{"source":"source", "headers":["header1"]}],
+        "rewrites":[{"source":"source", "destination":"destination"}],
         "redirects":[{"source":"source", "destination":"destination"}]
       }`,
     };
@@ -129,6 +134,10 @@ metadata:
       outputBundleOptions,
       path.join(tmpDir, ".next"),
       defaultNextVersion,
+      {
+        adapterPackageName: "@apphosting/adapter-nextjs",
+        adapterVersion: "14.0.1",
+      },
     );
     assert.rejects(
       async () => await validateOutputDirectory(outputBundleOptions, path.join(tmpDir, ".next")),
@@ -142,8 +151,8 @@ metadata:
       "public/publicfile": "",
       extrafile: "",
       ".next/routes-manifest.json": `{
-        "headers":[], 
-        "rewrites":[], 
+        "headers":[],
+        "rewrites":[],
         "redirects":[]
       }`,
     };
@@ -154,6 +163,10 @@ metadata:
       outputBundleOptions,
       path.join(tmpDir, ".next"),
       defaultNextVersion,
+      {
+        adapterPackageName: "@apphosting/adapter-nextjs",
+        adapterVersion: "14.0.1",
+      },
     );
     await validateOutputDirectory(outputBundleOptions, path.join(tmpDir, ".next"));
 
@@ -180,6 +193,7 @@ metadata:
       expectedOutputBundleOptions,
     );
   });
+
   afterEach(() => {
     fs.rmSync(tmpDir, { recursive: true, force: true });
   });

packages/@apphosting/adapter-nextjs/src/bin/build.ts

@@ -4,9 +4,11 @@ import {
   populateOutputBundleOptions,
   generateBuildOutput,
   validateOutputDirectory,
+  getAdapterMetadata,
 } from "../utils.js";
 import { join } from "path";
 import { getBuildOptions, runBuild } from "@apphosting/common";
+import { addRouteOverrides } from "../overrides.js";
 
 const root = process.cwd();
 const opts = getBuildOptions();
@@ -20,20 +22,24 @@ if (!process.env.FRAMEWORK_VERSION) {
 }
 await runBuild();
 
+const adapterMetadata = getAdapterMetadata();
+
 const { distDir } = await loadConfig(root, opts.projectDirectory);
 const nextBuildDirectory = join(opts.projectDirectory, distDir);
-
 const outputBundleOptions = populateOutputBundleOptions(
   root,
   opts.projectDirectory,
   nextBuildDirectory,
 );
 
+await addRouteOverrides(outputBundleOptions.outputDirectoryAppPath, distDir, adapterMetadata);
+
 await generateBuildOutput(
   root,
   opts.projectDirectory,
   outputBundleOptions,
   nextBuildDirectory,
   process.env.FRAMEWORK_VERSION,
+  adapterMetadata,
 );
 await validateOutputDirectory(outputBundleOptions, nextBuildDirectory);

packages/@apphosting/adapter-nextjs/src/constants.ts

@@ -1,9 +1,11 @@
 import type {
   PHASE_PRODUCTION_BUILD as NEXT_PHASE_PRODUCTION_BUILD,
   ROUTES_MANIFEST as NEXT_ROUTES_MANIFEST,
+  MIDDLEWARE_MANIFEST as NEXT_MIDDLEWARE_MANIFEST,
 } from "next/constants.js";
 
 // export next/constants ourselves so we don't have to dynamically import them
 // also this gives us a better heads up if the NextJS API changes
 export const PHASE_PRODUCTION_BUILD: typeof NEXT_PHASE_PRODUCTION_BUILD = "phase-production-build";
 export const ROUTES_MANIFEST: typeof NEXT_ROUTES_MANIFEST = "routes-manifest.json";
+export const MIDDLEWARE_MANIFEST: typeof NEXT_MIDDLEWARE_MANIFEST = "middleware-manifest.json";

packages/@apphosting/adapter-nextjs/src/interfaces.ts

@@ -71,7 +71,6 @@ export interface RoutesManifest {
     localeDetection?: false;
   };
 }
-
 // The output bundle options are specified here
 export interface OutputBundleOptions {
   /**
@@ -102,10 +101,52 @@ export interface OutputBundleOptions {
   outputStaticDirectoryPath: string;
 }
 
-// Metadata schema for bundle.yaml outputted by next.js adapter
-export interface Metadata {
+// Metadata schema for adapter metadata
+export interface AdapterMetadata {
   adapterPackageName: string;
   adapterVersion: string;
+}
+
+// Metadata schema for bundle.yaml outputted by next.js adapter
+export interface Metadata extends AdapterMetadata {
   framework: string;
   frameworkVersion: string;
 }
+
+// Metadata schema for asset bindings
+export interface AssetBinding {
+  filePath: string;
+  name: string;
+}
+
+// Metadata schema for middleware matchers
+export interface MiddlewareMatcher {
+  regexp: string;
+  locale?: false;
+  has?: RouteHas[];
+  missing?: RouteHas[];
+  originalSource: string;
+}
+
+// Metadata schema for edge function definitions
+export interface EdgeFunctionDefinition {
+  files: string[];
+  name: string;
+  page: string;
+  matchers: MiddlewareMatcher[];
+  wasm?: AssetBinding[];
+  assets?: AssetBinding[];
+  regions?: string[] | string;
+}
+
+// Metadata schema for middleware manifest
+export interface MiddlewareManifest {
+  version: number;
+  sortedMiddleware: string[];
+  middleware: {
+    [page: string]: EdgeFunctionDefinition;
+  };
+  functions: {
+    [page: string]: EdgeFunctionDefinition;
+  };
+}