feat: add OpenAPI documentation and comprehensive test suite

- Add OpenAPI schema endpoint at /openapi.json with proper logging
- Make server exportable for testing by wrapping app.listen in module check
- Add Jest test suite covering all API endpoints
- Improve request logging with IP addresses and timestamps
- Add development dependencies for testing (jest, supertest)

index.js

@@ -9,6 +9,9 @@ const PORT = process.env.PORT || 3000;
 // Load reasons from JSON
 const reasons = JSON.parse(fs.readFileSync('./reasons.json', 'utf-8'));
 
+// Load OpenAPI schema
+const openapiSchema = JSON.parse(fs.readFileSync('./openapi.json', 'utf-8'));
+
 // Rate limiter: 120 requests per minute per IP
 const limiter = rateLimit({
   windowMs: 60 * 1000, // 1 minute
@@ -21,17 +24,35 @@ const limiter = rateLimit({
 
 app.use(limiter);
 
+// Serve OpenAPI schema
+app.get('/openapi.json', (req, res) => {
+  const ip = req.headers['x-forwarded-for'] || req.ip;
+  const timestamp = new Date().toISOString();
+  console.log(`[${timestamp}] OpenAPI schema request from IP: ${ip}`);
+  res.json(openapiSchema);
+});
+
 // Random rejection reason endpoint
 app.get('/', (req, res) => {
+  const ip = req.headers['x-forwarded-for'] || req.ip;
+  const timestamp = new Date().toISOString();
+  console.log(`[${timestamp}] Request from IP: ${ip}`);
   const reason = reasons[Math.floor(Math.random() * reasons.length)];
   res.json({ reason });
 });
 
 app.get('/health', (req, res) => {
+  const ip = req.headers['x-forwarded-for'] || req.ip;
+  const timestamp = new Date().toISOString();
+  console.log(`[${timestamp}] Request from IP: ${ip}`);
   res.json({"status": "ok"});
 });
 
-// Start server
+// Start server only if this file is run directly
+if (require.main === module) {
   app.listen(PORT, () => {
     console.log(`No-as-a-Service is running on port ${PORT}`);
   });
+}
+
+module.exports = app;

package.json

@@ -4,12 +4,17 @@
   "description": "A lightweight API that returns random rejection or no reasons.",
   "main": "index.js",
   "scripts": {
-    "start": "node index.js"
+    "start": "node index.js",
+    "test": "jest"
   },
   "author": "hotheadhacker",
   "license": "MIT",
   "dependencies": {
     "express": "^4.18.2",
     "express-rate-limit": "^7.0.0"
+  },
+  "devDependencies": {
+    "jest": "^30.1.2",
+    "supertest": "^7.1.4"
   }
 }

test/api.test.js

@@ -0,0 +1,28 @@
+const request = require('supertest');
+
+describe('API Endpoints', () => {
+  let app;
+
+  beforeAll(() => {
+    app = require('../index.js');
+  });
+
+  test('should return a random reason at root endpoint', async () => {
+    const response = await request(app)
+      .get('/')
+      .expect(200)
+      .expect('Content-Type', /application\/json/);
+      
+    expect(response.body).toHaveProperty('reason');
+    expect(typeof response.body.reason).toBe('string');
+  });
+
+  test('should return health status at /health endpoint', async () => {
+    const response = await request(app)
+      .get('/health')
+      .expect(200)
+      .expect('Content-Type', /application\/json/);
+      
+    expect(response.body).toEqual({ status: 'ok' });
+  });
+});

test/openapi.test.js

@@ -0,0 +1,23 @@
+const request = require('supertest');
+const fs = require('fs');
+
+describe('OpenAPI Schema Endpoint', () => {
+  let app;
+
+  beforeAll(() => {
+    // Import the app after modifications
+    app = require('../index.js');
+  });
+
+  test('should serve OpenAPI schema at /openapi.json', async () => {
+    // Read the expected schema from the file
+    const expectedSchema = JSON.parse(fs.readFileSync('./openapi.json', 'utf-8'));
+    
+    const response = await request(app)
+      .get('/openapi.json')
+      .expect(200)
+      .expect('Content-Type', /application\/json/);
+      
+    expect(response.body).toEqual(expectedSchema);
+  });
+});