/**
* Mock MCP Server
*
* Lightweight HTTP server that serves fixture data for testing.
* Uses Node.js built-in http module (no Express).
*
* PRD #354: REST API Route Registry with Auto-Generated OpenAPI and Test Fixtures
*/
import { createServer, IncomingMessage, ServerResponse } from 'node:http';
import { readFile } from 'node:fs/promises';
import { join, dirname } from 'node:path';
import { URL, fileURLToPath } from 'node:url';
import { matchRoute, getAllRoutes } from './routes.js';
const PORT = parseInt(process.env.PORT || '3001', 10);
// ESM-compatible __dirname equivalent
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
// Fixtures are in ../fixtures relative to dist/ (or ./fixtures when running from source)
const FIXTURES_DIR = join(__dirname, '..', 'fixtures');
/**
* Set CORS headers for browser compatibility
*/
function setCorsHeaders(res: ServerResponse): void {
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
}
/**
* Send JSON response
*/
function sendJson(res: ServerResponse, status: number, data: unknown): void {
res.writeHead(status, { 'Content-Type': 'application/json' });
res.end(JSON.stringify(data, null, 2));
}
/**
* Load fixture file
*/
async function loadFixture(fixturePath: string): Promise<unknown> {
const fullPath = join(FIXTURES_DIR, fixturePath);
const content = await readFile(fullPath, 'utf-8');
return JSON.parse(content);
}
/**
* Handle incoming HTTP requests
*/
async function handleRequest(req: IncomingMessage, res: ServerResponse): Promise<void> {
setCorsHeaders(res);
// Handle CORS preflight
if (req.method === 'OPTIONS') {
res.writeHead(204);
res.end();
return;
}
const url = new URL(req.url || '/', `http://localhost:${PORT}`);
const path = url.pathname;
const method = req.method || 'GET';
// Health check endpoint
if (path === '/health' && method === 'GET') {
sendJson(res, 200, {
status: 'healthy',
service: 'mock-mcp-server',
timestamp: new Date().toISOString(),
});
return;
}
// List all available routes (for debugging)
if (path === '/routes' && method === 'GET') {
const routes = getAllRoutes().map((r) => ({
method: r.method,
path: r.path,
description: r.description,
hasFixture: !!r.fixture,
}));
sendJson(res, 200, { routes });
return;
}
// Match against API routes
const match = matchRoute(method, path);
if (!match) {
sendJson(res, 404, {
success: false,
error: {
code: 'NOT_FOUND',
message: `No route matches ${method} ${path}`,
},
});
return;
}
const { route, params } = match;
// Check if fixture is configured
if (!route.fixture) {
sendJson(res, 501, {
success: false,
error: {
code: 'NOT_IMPLEMENTED',
message: `Route ${method} ${route.path} exists but has no fixture configured yet`,
hint: 'This endpoint is recognized but awaiting fixture implementation',
},
route: {
method: route.method,
path: route.path,
description: route.description,
params,
},
});
return;
}
// Load and return fixture
try {
const fixture = await loadFixture(route.fixture);
sendJson(res, 200, fixture);
} catch (error) {
const errorMessage = error instanceof Error ? error.message : 'Unknown error';
sendJson(res, 500, {
success: false,
error: {
code: 'FIXTURE_LOAD_ERROR',
message: `Failed to load fixture: ${route.fixture}`,
details: errorMessage,
},
});
}
}
/**
* Start the server
*/
const server = createServer((req, res) => {
handleRequest(req, res).catch((error) => {
console.error('Unhandled error:', error);
sendJson(res, 500, {
success: false,
error: {
code: 'INTERNAL_ERROR',
message: 'An unexpected error occurred',
},
});
});
});
server.listen(PORT, () => {
console.log(`Mock MCP Server running on http://localhost:${PORT}`);
console.log('');
console.log('Endpoints:');
console.log(` GET /health - Health check`);
console.log(` GET /routes - List all routes`);
console.log('');
console.log('API routes (501 until fixtures are configured):');
for (const route of getAllRoutes()) {
const status = route.fixture ? ' [OK]' : '[TODO]';
console.log(` ${status} ${route.method.padEnd(6)} ${route.path}`);
}
});
