chai-http

What is chai-http?

chai-http is a plugin for the Chai assertion library that provides an interface for testing HTTP APIs. It allows you to make HTTP requests and assertions about the responses, making it useful for testing RESTful APIs and other web services.

What are chai-http's main functionalities?

Making HTTP Requests

This feature allows you to make HTTP requests to your server. In this example, a GET request is made to the '/api/resource' endpoint, and assertions are made about the response status and body.

const chai = require('chai');
const chaiHttp = require('chai-http');
const server = require('../app'); // Your server file
const should = chai.should();

chai.use(chaiHttp);

describe('GET /api/resource', () => {
  it('it should GET all the resources', (done) => {
    chai.request(server)
        .get('/api/resource')
        .end((err, res) => {
            res.should.have.status(200);
            res.body.should.be.a('array');
            done();
        });
  });
});

Testing POST Requests

This feature allows you to test POST requests. In this example, a POST request is made to the '/api/resource' endpoint with a sample resource object, and assertions are made about the response status and body.

const chai = require('chai');
const chaiHttp = require('chai-http');
const server = require('../app'); // Your server file
const should = chai.should();

chai.use(chaiHttp);

describe('POST /api/resource', () => {
  it('it should POST a new resource', (done) => {
    let resource = {
      name: 'Sample Resource',
      description: 'This is a sample resource'
    }
    chai.request(server)
        .post('/api/resource')
        .send(resource)
        .end((err, res) => {
            res.should.have.status(201);
            res.body.should.be.a('object');
            res.body.should.have.property('name').eql('Sample Resource');
            done();
        });
  });
});

Testing PUT Requests

This feature allows you to test PUT requests. In this example, a PUT request is made to the '/api/resource/:id' endpoint to update an existing resource, and assertions are made about the response status and body.

const chai = require('chai');
const chaiHttp = require('chai-http');
const server = require('../app'); // Your server file
const should = chai.should();

chai.use(chaiHttp);

describe('PUT /api/resource/:id', () => {
  it('it should UPDATE a resource given the id', (done) => {
    let resource = new Resource({name: 'Old Resource', description: 'Old description'});
    resource.save((err, resource) => {
      chai.request(server)
          .put('/api/resource/' + resource.id)
          .send({name: 'Updated Resource', description: 'Updated description'})
          .end((err, res) => {
              res.should.have.status(200);
              res.body.should.be.a('object');
              res.body.should.have.property('name').eql('Updated Resource');
              done();
          });
    });
  });
});

Testing DELETE Requests

This feature allows you to test DELETE requests. In this example, a DELETE request is made to the '/api/resource/:id' endpoint to delete an existing resource, and assertions are made about the response status and body.

const chai = require('chai');
const chaiHttp = require('chai-http');
const server = require('../app'); // Your server file
const should = chai.should();

chai.use(chaiHttp);

describe('DELETE /api/resource/:id', () => {
  it('it should DELETE a resource given the id', (done) => {
    let resource = new Resource({name: 'Resource to be deleted', description: 'This resource will be deleted'});
    resource.save((err, resource) => {
      chai.request(server)
          .delete('/api/resource/' + resource.id)
          .end((err, res) => {
              res.should.have.status(200);
              res.body.should.be.a('object');
              res.body.should.have.property('message').eql('Resource successfully deleted');
              done();
          });
    });
  });
});

Other packages similar to chai-http

supertest

Supertest is a popular library for testing HTTP servers. It provides a high-level abstraction for testing HTTP, making it easy to test APIs. Compared to chai-http, Supertest is more focused on HTTP testing and does not integrate with Chai's assertion library, but it can be used with any assertion library.

axios

Axios is a promise-based HTTP client for the browser and Node.js. While it is not specifically designed for testing, it can be used to make HTTP requests in tests. Compared to chai-http, Axios is more general-purpose and does not provide built-in testing utilities, but it can be combined with assertion libraries like Chai for testing.

request

Request is a simplified HTTP client for making HTTP requests. It is not specifically designed for testing, but it can be used to make HTTP requests in tests. Compared to chai-http, Request is more general-purpose and does not provide built-in testing utilities, but it can be combined with assertion libraries like Chai for testing.

README

Chai HTTP

HTTP integration testing with Chai assertions.

Features

• integration test request composition
• test http apps or external services
• assertions for common http tasks
• chai expect and should interfaces

Installation

This is an addon plugin for the Chai Assertion Library. Install via npm.

npm install chai-http

Plugin

Use this plugin as you would all other Chai plugins.

import * as chai from "chai";
import chaiHttp from "chai-http";

chai.use(chaiHttp);

// if you need to access `request`
import {default as chaiHttp, request} from "chai-http";
chai.use(chaiHttp);

request.get(...).send(...);

// or setting up an app
request.execute(app);

To use Chai HTTP on a web page, please use the latest v4 version for now.

Integration Testing

Chai HTTP provides an interface for live integration testing via superagent. To do this, you must first construct a request to an application or url.

Upon construction you are provided a chainable api that allows you to specify the http VERB request (get, post, etc) that you wish to invoke.

Application / Server

You may use a function (such as an express or connect app) or a node.js http(s) server as the foundation for your request. If the server is not running, chai-http will find a suitable port to listen on for a given test.

Note: This feature is only supported on Node.js, not in web browsers.

import {request} from 'chai-http';

request.execute(app)
  .get('/')

When passing an app to request.execute(), it will automatically open the server for incoming requests (by calling listen()) and, once a request has been made the server will automatically shut down (by calling .close()). If you want to keep the server open, perhaps if you're making multiple requests, you must call .keepOpen() after .request(), and manually close the server down:

import {request} from 'chai-http';

const requester = request.Request(app).keepOpen()

Promise.all([
  requester.get('/a'),
  requester.get('/b'),
])
.then(responses => { /* ... */ })
.then(() => requester.close())

URL

You may also use a base url as the foundation of your request.

import {request} from 'chai-http';

request.execute('http://localhost:8080')
  .get('/')

Setting up requests

Once a request is created with a given VERB (get, post, etc), you chain on these additional methods to create your request:

Method	Purpose
.set(key, value)	Set request headers
.send(data)	Set request data (default type is JSON)
.type(dataType)	Change the type of the data sent from the .send() method (xml, form, etc)
.attach(field, file, attachment)	Attach a file
.auth(username, password)	Add auth headers for Basic Authentication
.query(parmasObject)	Chain on some GET parameters

Examples:

.set()

import {request} from 'chai-http';

// Set a request header
request.execute(app)
  .put('/user/me')
  .set('Content-Type', 'application/json')
  .send({ password: '123', confirmPassword: '123' })

.send()

import {request} from 'chai-http';

// Send some JSON
request.execute(app)
  .put('/user/me')
  .send({ password: '123', confirmPassword: '123' })

.type()

import {request} from 'chai-http';

// Send some Form Data
request.execute(app)
  .post('/user/me')
  .type('form')
  .send({
    '_method': 'put',
    'password': '123',
    'confirmPassword': '123'
  })

.attach()

import {request} from 'chai-http';

// Attach a file
request.execute(app)
  .post('/user/avatar')
  .attach('imageField', fs.readFileSync('avatar.png'), 'avatar.png')

.auth()

import {request} from 'chai-http';

// Authenticate with Basic authentication
request.execute(app)
  .get('/protected')
  .auth('user', 'pass')

// Authenticate with Bearer Token
request.execute(app)
  .get('/protected')
  .auth(accessToken, { type: 'bearer' })

.query()

import {request} from 'chai-http';

// Chain some GET query parameters
request.execute(app)
  .get('/search')
  .query({name: 'foo', limit: 10}) // /search?name=foo&limit=10

Dealing with the response - traditional

In the following examples we use Chai's Expect assertion library:

const { expect } = chai;

To make the request and assert on its response, the end method can be used:

import {request} from 'chai-http';

request.execute(app)
  .put('/user/me')
  .send({ password: '123', confirmPassword: '123' })
  .end((err, res) => {
     expect(err).to.be.null;
     expect(res).to.have.status(200);
  });

Caveat

Because the end function is passed a callback, assertions are run asynchronously. Therefore, a mechanism must be used to notify the testing framework that the callback has completed. Otherwise, the test will pass before the assertions are checked.

For example, in the Mocha test framework, this is accomplished using the done callback, which signal that the callback has completed, and the assertions can be verified:

import {request} from 'chai-http';

it('fails, as expected', function(done) { // <= Pass in done callback
  request.execute('http://localhost:8080')
  .get('/')
  .end((err, res) => {
    expect(res).to.have.status(123);
    done();                               // <= Call done to signal callback end
  });
});

it('succeeds silently!', () => {   // <= No done callback
  request.execute('http://localhost:8080')
  .get('/')
  .end((err, res) => {
    expect(res).to.have.status(123);    // <= Test completes before this runs
  });
});

When done is passed in, Mocha will wait until the call to done(), or until the timeout expires. done also accepts an error parameter when signaling completion.

Dealing with the response - Promises

If Promise is available, request becomes a Promise capable library - and chaining of thens becomes possible:

import {request} from 'chai-http';

request.execute(app)
  .put('/user/me')
  .send({ password: '123', confirmPassword: '123' })
  .then((res) => {
     expect(res).to.have.status(200);
  })
  .catch((err) => {
     throw err;
  });

Retaining cookies with each request

Sometimes you need to keep cookies from one request, and send them with the next (for example, when you want to login with the first request, then access an authenticated-only resource later). For this, .request.agent() is available:

import {request} from 'chai-http';

// Log in
const agent = request.agent(app)
agent
  .post('/session')
  .send({ username: 'me', password: '123' })
  .then((res) => {
    expect(res).to.have.cookie('sessionid');
    // The `agent` now has the sessionid cookie saved, and will send it
    // back to the server in the next request:
    return agent.get('/user/me')
      .then((res) => {
         expect(res).to.have.status(200);
      });
  });

Note: The server started by request.agent(app) will not automatically close following the test(s). You should call agent.close() after your tests to ensure your program exits.

Assertions

The Chai HTTP module provides a number of assertions for the expect and should interfaces.

.status (code)

• @param {Number} status number

Assert that a response has a supplied status.

expect(res).to.have.status(200);

.header (key[, value])

• @param {String} header key (case insensitive)
• @param {String|RegExp} header value (optional)

Assert that a Response or Request object has a header. If a value is provided, equality to value will be asserted. You may also pass a regular expression to check.

Note: When running in a web browser, the same-origin policy only allows Chai HTTP to read certain headers, which can cause assertions to fail.

expect(req).to.have.header('x-api-key');
expect(req).to.have.header('content-type', 'text/plain');
expect(req).to.have.header('content-type', /^text/);

.headers

Assert that a Response or Request object has headers.

Note: When running in a web browser, the same-origin policy only allows Chai HTTP to read certain headers, which can cause assertions to fail.

expect(req).to.have.headers;

.ip

Assert that a string represents valid ip address.

expect('127.0.0.1').to.be.an.ip;
expect('2001:0db8:85a3:0000:0000:8a2e:0370:7334').to.be.an.ip;

.json / .text / .html

Assert that a Response or Request object has a given content-type.

expect(req).to.be.json;
expect(req).to.be.html;
expect(req).to.be.text;

.charset

Assert that a Response or Request object has a given charset.

expect(req).to.have.charset('utf-8');

.redirect

Assert that a Response object has a redirect status code.

expect(res).to.redirect;
expect(res).to.not.redirect;

.redirectTo

• @param {String|RegExp} location url

Assert that a Response object redirects to the supplied location.

expect(res).to.redirectTo('http://example.com');
expect(res).to.redirectTo(/^\/search\/results\?orderBy=desc$/);

.param

• @param {String} parameter name
• @param {String} parameter value

Assert that a Request object has a query string parameter with a given key, (optionally) equal to value

expect(req).to.have.param('orderby');
expect(req).to.have.param('orderby', 'date');
expect(req).to.not.have.param('limit');

.cookie

• @param {String} parameter name
• @param {String} parameter value

Assert that a Request or Response object has a cookie header with a given key, (optionally) equal to value

expect(req).to.have.cookie('session_id');
expect(req).to.have.cookie('session_id', '1234');
expect(req).to.not.have.cookie('PHPSESSID');
expect(res).to.have.cookie('session_id');
expect(res).to.have.cookie('session_id', '1234');
expect(res).to.not.have.cookie('PHPSESSID');

Releasing

chai-http is released with semantic-release using the plugins:

• commit-analyzer to determine the next version from commit messages.
• release-notes-generator to summarize release in
• changelog to update the CHANGELOG.md file.
• github to publish a GitHub release.
• git to commit release assets.
• npm to publish to npm.

License

(The MIT License)

Copyright (c) Jake Luer [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.