/**
* Express Application Fixture
*
* Sample Express application with various route patterns for testing
* REST endpoint detection in the pattern matcher.
*
* Patterns tested:
* - Basic HTTP methods (GET, POST, PUT, DELETE, PATCH)
* - Path parameters (:id, :userId)
* - Optional parameters (:id?)
* - Regex constraints (:id(\\d+))
* - Validation middleware (Zod, Joi)
* - Multiple middleware handlers
* - Route chaining
* - app.all() and app.use()
*/
import express, { Request, Response, NextFunction } from 'express';
import { z } from 'zod';
// Types for demonstration
interface User {
id: string;
name: string;
email: string;
}
interface CreateUserDto {
name: string;
email: string;
}
interface UpdateUserDto {
name?: string;
email?: string;
}
// Mock validation middleware
function validateBody<T>(schema: z.ZodType<T>) {
return (req: Request, res: Response, next: NextFunction) => {
next();
};
}
function validateQuery<T>(schema: z.ZodType<T>) {
return (req: Request, res: Response, next: NextFunction) => {
next();
};
}
// Create Express app
const app = express();
// ============================================================================
// Basic HTTP Methods - app.METHOD()
// ============================================================================
// GET - List all users
app.get('/users', (req: Request, res: Response) => {
res.json({ users: [] });
});
// GET - Get user by ID with path parameter
app.get('/users/:id', (req: Request, res: Response) => {
const { id } = req.params;
res.json({ id, name: 'John Doe', email: 'john@example.com' });
});
// POST - Create user
app.post('/users', (req: Request, res: Response) => {
const user = req.body as CreateUserDto;
res.status(201).json({ id: '123', ...user });
});
// PUT - Update user (full replacement)
app.put('/users/:id', (req: Request, res: Response) => {
const { id } = req.params;
const user = req.body as UpdateUserDto;
res.json({ id, ...user });
});
// DELETE - Delete user
app.delete('/users/:id', (req: Request, res: Response) => {
res.status(204).send();
});
// PATCH - Partial update
app.patch('/users/:id', (req: Request, res: Response) => {
const { id } = req.params;
const updates = req.body as Partial<UpdateUserDto>;
res.json({ id, ...updates });
});
// OPTIONS - CORS preflight
app.options('/users', (req: Request, res: Response) => {
res.set('Allow', 'GET, POST, OPTIONS');
res.status(204).send();
});
// HEAD - Check resource exists
app.head('/users/:id', (req: Request, res: Response) => {
res.status(200).send();
});
// ALL - Match all HTTP methods
app.all('/health', (req: Request, res: Response) => {
res.json({ status: 'ok' });
});
// ============================================================================
// Path Parameter Variations
// ============================================================================
// Multiple path parameters
app.get('/users/:userId/posts/:postId', (req: Request, res: Response) => {
const { userId, postId } = req.params;
res.json({ userId, postId });
});
// Optional path parameter
app.get('/files/:filename?', (req: Request, res: Response) => {
const { filename } = req.params;
res.json({ filename: filename || 'index.html' });
});
// Regex-constrained parameter (numeric ID)
app.get('/products/:id(\\d+)', (req: Request, res: Response) => {
const { id } = req.params;
res.json({ id: parseInt(id, 10) });
});
// Regex-constrained parameter (UUID)
app.get('/orders/:orderId([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})', (req: Request, res: Response) => {
res.json({ orderId: req.params.orderId });
});
// Wildcard path (catch-all)
app.get('/docs/*', (req: Request, res: Response) => {
res.json({ path: req.params[0] });
});
// ============================================================================
// Validation Middleware - Zod
// ============================================================================
// Zod schemas
const CreateUserSchema = z.object({
name: z.string().min(1),
email: z.string().email(),
});
const UpdateUserSchema = z.object({
name: z.string().min(1).optional(),
email: z.string().email().optional(),
});
const QuerySchema = z.object({
page: z.coerce.number().int().positive().optional(),
limit: z.coerce.number().int().positive().max(100).optional(),
sort: z.enum(['asc', 'desc']).optional(),
});
// POST with Zod body validation
app.post('/api/users',
validateBody(CreateUserSchema),
(req: Request, res: Response) => {
res.status(201).json(req.body);
}
);
// PUT with Zod body validation
app.put('/api/users/:id',
validateBody(UpdateUserSchema),
(req: Request, res: Response) => {
res.json({ id: req.params.id, ...req.body });
}
);
// GET with Zod query validation
app.get('/api/users',
validateQuery(QuerySchema),
(req: Request, res: Response) => {
res.json({ users: [], pagination: req.query });
}
);
// ============================================================================
// Multiple Middleware Handlers
// ============================================================================
// Authentication middleware
function authMiddleware(req: Request, res: Response, next: NextFunction) {
const token = req.headers.authorization;
if (!token) {
return res.status(401).json({ error: 'Unauthorized' });
}
next();
}
// Rate limiting middleware
function rateLimitMiddleware(req: Request, res: Response, next: NextFunction) {
next();
}
// Logging middleware
function logMiddleware(req: Request, res: Response, next: NextFunction) {
console.log(`${req.method} ${req.path}`);
next();
}
// Route with multiple middleware
app.get('/protected/resource',
logMiddleware,
authMiddleware,
rateLimitMiddleware,
(req: Request, res: Response) => {
res.json({ secret: 'data' });
}
);
// Route with validation AND auth middleware
app.post('/protected/resource',
authMiddleware,
validateBody(CreateUserSchema),
(req: Request, res: Response) => {
res.status(201).json(req.body);
}
);
// ============================================================================
// Route Chaining - app.route()
// ============================================================================
app.route('/articles')
.get((req: Request, res: Response) => {
res.json({ articles: [] });
})
.post((req: Request, res: Response) => {
res.status(201).json(req.body);
});
app.route('/articles/:id')
.get((req: Request, res: Response) => {
res.json({ id: req.params.id });
})
.put((req: Request, res: Response) => {
res.json({ id: req.params.id, ...req.body });
})
.delete((req: Request, res: Response) => {
res.status(204).send();
});
// ============================================================================
// Typed Responses - res.json<T>()
// ============================================================================
interface ProfileResponse {
id: string;
name: string;
email: string;
createdAt: string;
}
interface ErrorResponse {
error: string;
code: number;
}
app.get('/profile', (req: Request, res: Response) => {
// TypeScript type annotation on response
const profile: ProfileResponse = {
id: '123',
name: 'John',
email: 'john@example.com',
createdAt: new Date().toISOString(),
};
res.json(profile);
});
app.get('/profile/:id', (req: Request, res: Response): void => {
// Using res.json<T>() generic
if (!req.params.id) {
res.status(400).json<ErrorResponse>({ error: 'Missing ID', code: 400 });
return;
}
res.json<ProfileResponse>({
id: req.params.id,
name: 'John',
email: 'john@example.com',
createdAt: new Date().toISOString(),
});
});
// ============================================================================
// app.use() - Middleware and Router Mounting
// ============================================================================
// Middleware for all routes
app.use(express.json());
// Prefix-based middleware
app.use('/api', (req: Request, res: Response, next: NextFunction) => {
req.headers['x-api-version'] = '1';
next();
});
export default app;
