@tracecov/express

Automatic OpenAPI coverage capture for Express servers. One call records every request the app handles — supertest, a real HTTP client, or a browser — into a @tracecov/core coverage map. Works on Express 4 and 5.

Installation

npm install @tracecov/express

Quick Start

import express from 'express';
import request from 'supertest';
import { CoverageMap } from '@tracecov/core';
import { instrumentExpress } from '@tracecov/express';

const app = express();
app.use(express.json());
app.get('/items', (req, res) => res.json([]));

const coverage = CoverageMap.fromPath('openapi.json');
instrumentExpress(app, coverage);

// drive it however your tests already do:
await request(app).get('/items?limit=10');

coverage.saveHtmlReport({ outputFile: 'coverage.html' });

Pass { onError } to handle recording failures yourself. For multi-file coverage in Vitest, see @tracecov/vitest.

Documentation

• Integration guide
• API reference