feat(api): example middleware (#48434)

* feat(api): add middleware example

* feat(api): add `@fastify/middie`, reorder for alphabetness

* [skip-ci] [skip ci]

api/index.ts

@@ -1,8 +1,10 @@
 import { config } from 'dotenv';
 config({ path: '../.env' });
 import Fastify from 'fastify';
+import middie from '@fastify/middie';
 import { testRoutes } from './routes/test';
 import { dbConnector } from './db';
+import { testMiddleware } from './middleware';
 
 const fastify = Fastify({
   logger: { level: process.env.NODE_ENV === 'development' ? 'debug' : 'fatal' }
@@ -12,10 +14,18 @@ fastify.get('/', async (_request, _reply) => {
   return { hello: 'world' };
 });
 
-void fastify.register(dbConnector);
-void fastify.register(testRoutes);
-
 const start = async () => {
+  // NOTE: Awaited to ensure `.use` is registered on `fastify`
+  await fastify.register(middie);
+
+  // @ts-expect-error Types are not exported from Fastify,
+  // and TypeScript is not smart enough to realise types
+  // defined within this module have the same signature
+  void fastify.use('/test', testMiddleware);
+
+  void fastify.register(dbConnector);
+  void fastify.register(testRoutes);
+
   try {
     const port = Number(process.env.PORT) || 3000;
     fastify.log.info(`Starting server on port ${port}`);

api/middleware/index.ts

@@ -1,3 +1,16 @@
+import { NextFunction } from '../utils';
+
 export async function auth0Verify() {
   // Verify user authorization code with Auth0
 }
+
+export function testMiddleware(
+  req: Request,
+  _res: Response,
+  next: NextFunction
+) {
+  //
+  console.log('Test middleware running');
+  console.log(req.headers);
+  next();
+}

api/package.json

@@ -1,31 +1,40 @@
 {
-  "name": "@freecodecamp/api",
-  "version": "0.0.1",
+  "author": "freeCodeCamp <team@freecodecamp.org>",
+  "bugs": {
+    "url": "https://github.com/freeCodeCamp/freeCodeCamp/issues"
+  },
+  "dependencies": {
+    "@fastify/middie": "8.0.0",
+    "@fastify/mongodb": "6.1.0",
+    "fastify": "4.9.2",
+    "fastify-plugin": "4.3.0"
+  },
   "description": "The freeCodeCamp.org open-source codebase and curriculum",
-  "license": "BSD-3-Clause",
-  "private": true,
   "engines": {
     "node": ">=18",
     "npm": ">=8"
   },
+  "homepage": "https://github.com/freeCodeCamp/freeCodeCamp#readme",
+  "license": "BSD-3-Clause",
+  "main": "none",
+  "name": "@freecodecamp/api",
+  "nodemonConfig": {
+    "env": {
+      "NODE_ENV": "development"
+    },
+    "ignore": [
+      "**/*.js"
+    ]
+  },
+  "private": true,
   "repository": {
     "type": "git",
     "url": "git+https://github.com/freeCodeCamp/freeCodeCamp.git"
   },
-  "bugs": {
-    "url": "https://github.com/freeCodeCamp/freeCodeCamp/issues"
-  },
-  "homepage": "https://github.com/freeCodeCamp/freeCodeCamp#readme",
-  "author": "freeCodeCamp <team@freecodecamp.org>",
-  "main": "none",
   "scripts": {
     "build": "tsc index.ts",
     "start": "NODE_ENV=production node index.js",
-    "develop": "NODE_ENV=development nodemon index.ts"
+    "develop": "nodemon index.ts"
   },
-  "dependencies": {
-    "@fastify/mongodb": "6.1.0",
-    "fastify": "4.9.2",
-    "fastify-plugin": "4.3.0"
-  }
+  "version": "0.0.1"
 }

api/utils/index.ts

@@ -13,3 +13,7 @@ function sha256(buf: Buffer) {
   return createHash('sha256').update(buf).digest();
 }
 export const challenge = base64URLEncode(sha256(Buffer.from(verifier)));
+
+// This is used for Fastify middleware, but is not exported from Fastify itself.
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type NextFunction = (err?: any) => void;