Chai Connect Middleware

0.3.1 verified Thu Apr 23 auth: no javascript abandoned

The `chai-connect-middleware` package provides helper functions specifically designed for testing Connect.js middleware using the Chai assertion library. Its sole stable version, 0.3.1, was published in January 2014. Given its last update was over a decade ago and it targets very old Node.js versions (specifically, `>= 0.4.0`), this library is no longer actively maintained, and future releases are not expected. This utility enables developers to wrap Connect middleware execution, allowing for precise control over the simulated `req` and `res` objects and handling the middleware's invocation of `next()` or `end()` for assertion purposes. While it offered a specialized approach to middleware testing, contemporary practices for testing Connect or Express middleware often leverage higher-level HTTP testing libraries like Supertest or `chai-http`, or directly unit test middleware functions. This makes `chai-connect-middleware` largely obsolete in modern JavaScript development workflows.

Common errors

error TypeError: require is not a function ↓

cause Attempting to `import` this CommonJS-only package in an ES Module context.

fix

Ensure your test file uses CommonJS (.js files without "type": "module" in package.json, or explicitly using require()).

error Error: Cannot find module 'chai-connect-middleware' ↓

cause The package is not installed or not resolvable in the current environment.

fix

Run npm install chai-connect-middleware to install the package.

error TypeError: chai.connect is not a function ↓

cause The `chai-connect-middleware` plugin has not been registered with Chai via `chai.use(connect)`.

fix

Add chai.use(connect); after requiring both chai and chai-connect-middleware.

Warnings

breaking This package targets Node.js versions `>=0.4.0`, which are extremely outdated. It will likely not run on modern Node.js versions due to fundamental API changes and lack of maintenance. ↓

fix Consider using modern middleware testing libraries like `supertest` or `chai-http` which are actively maintained and compatible with current Node.js versions and testing paradigms.

deprecated The package's last update was over 10 years ago, and its dependencies (Connect.js, older Chai versions) are also largely outdated or superseded. Modern testing patterns for HTTP middleware have evolved beyond this specific utility. ↓

fix Migrate to actively maintained libraries such as `supertest` for integration testing of HTTP endpoints, or directly unit test middleware functions using mocks for `req`, `res`, and `next`.

gotcha This package is CommonJS-only and does not support ES Modules (`import`/`export`) syntax directly. Attempting to use it in an ESM environment will result in module resolution errors. ↓

fix If you must use this package in a mixed environment, ensure it is `require()`d from a CommonJS context. For new projects, prefer ESM-compatible testing tools.

gotcha Security vulnerabilities may exist in this unmaintained package or its transitive dependencies. As it hasn't received updates in over a decade, any discovered security flaws would remain unpatched. ↓

fix Avoid using unmaintained software in production-critical test suites. Regularly audit your dependency tree and prioritize active projects for testing infrastructure.

Install

npm install chai-connect-middleware

yarn add chai-connect-middleware

pnpm add chai-connect-middleware

Imports

chai
wrong
```
import chai from 'chai';
```
correct
```
const chai = require('chai');
```
This package, and its dependency 'chai' in the context of its release, are CommonJS-only. ESM imports will fail.

connectMiddlewarePlugin

wrong

import connect from 'chai-connect-middleware';

correct

const connect = require('chai-connect-middleware');

The package is CommonJS-only. Direct ESM imports are not supported.

usePlugin
```
chai.use(connect);
```
This is the standard way to register Chai plugins, making the `.connect` helper available.

Quickstart

This quickstart demonstrates how to use `chai-connect-middleware` with Mocha to test a simple Connect-style middleware, simulating a request and asserting on the response.

const chai = require('chai');
const connect = require('chai-connect-middleware');
const expect = chai.expect;

chai.use(connect);

// A dummy Connect/Express-style middleware for demonstration
function dummyMiddleware(req, res, next) {
  if (req.query && req.query.hello) {
    res.body = `Hello, ${req.query.hello}`;
    res.statusCode = 200;
    res.end();
  } else {
    next();
  }
}

describe('middleware test', function() {
  let resResult;
    
  before(function(done) {
    chai.connect(dummyMiddleware)
      .req(function(req) {
        req.query = { hello: 'World' };
        req.method = 'GET'; // Often needed for robust middleware testing
        req.url = '/';
      })
      .end(function(r) {
        resResult = r;
        done();
      })
      .dispatch(new Error('Middleware did not call next() or end()'));
  });

  it('should send correct body', function() {
    expect(resResult.body).to.equal('Hello, World');
  });

  it('should have a 200 status code', function() {
    expect(resResult.statusCode).to.equal(200);
  });
});