reqres

3.0.1 verified Sat Apr 25 auth: no javascript

Stub request and response objects for testing Express applications and middleware. Provides `req()` and `res()` functions that create mock objects with sensible defaults and sinon stubs on methods. Version 3.0.1 is current, maintained as needed. Key differentiator: integrates sinon for stub/spy assertions, customisable sinon instance, emits 'end' events on response methods. Alternative to node-mocks-http or express-mocks-http.

Common errors

error TypeError: reqres.req is not a function ↓

cause Importing named exports incorrectly in CommonJS when using default import pattern.

fix

Use const { req } = require('reqres');

error Cannot find module 'sinon' ↓

cause Sinon is a peer dependency; not installed automatically.

fix

Run npm install sinon --save-dev

error AssertionError: expected res.json to have been called with arguments { user: '...' } but it was never called ↓

cause Response method 'end' event may not be emitted if async middleware doesn't call next() or res.json() before assertion.

fix

Wrap assertion in res.on('end', ...) callback.

Warnings

breaking Default headers are not set on response object. res.setHeader and res.getHeader may be stubs that do not store values. ↓

fix Provide custom headers via res({ headers: {...} }) or manually set in tests.

deprecated Using reqres.req() and reqres.res() as non-destructured calls is deprecated in favor of destructured imports. ↓

fix Use const { req, res } = require('reqres'); then call req(), res().

gotcha The 'end' event on res is emitted only for methods like json, send, sendStatus, etc. Not all response methods emit it. ↓

fix Check source or readme for full list of methods that emit 'end'.

gotcha reqres does not support ES modules (import). Must use require(). ↓

fix Use CommonJS require() or find an ESM-compatible alternative.

Install

npm install reqres

yarn add reqres

pnpm add reqres

Imports

req

wrong

const reqres = require('reqres'); const req = reqres.req;

correct

const { req } = require('reqres');

CommonJS destructuring is typical; default export is the module itself, not a function.

res

wrong

const res = require('reqres').res;

correct

const { res } = require('reqres');

Both work, but destructuring is idiomatic.

sinon

wrong

import { sinon } from 'reqres';

correct

const reqres = require('reqres'); reqres.sinon = require('sinon');

sinon is not exported; set it as a property on the module. ESM not supported.

Quickstart

Shows creating mock req and res objects with custom properties and invoking middleware.

const { req, res } = require('reqres');
const myMiddleware = (req, res, next) => {
  req.session = req.session || {};
  req.session.path = req.path;
  next();
};

const mockReq = req({ path: '/test', session: {} });
const mockRes = res();

myMiddleware(mockReq, mockRes, (err) => {
  console.log(mockReq.session.path); // '/test'
});