Examples Using Mocha and Related Tools

In this tutorial we are going to look at live codes where mocha has can be used:

Mocha examples

//when testing with babel
import { equal } from "assert";
import { add } from "../src";

describe('Babel usage suite', () => {
  it('it should add numbers correctly', () => {
    equal(add(2, 3), 5);
  });
});
//you can use mocha with karma
const expect = chai.expect;

describe('Array', function () {
  describe('.push()', function () {
    it('it should append a value', function () {
      var arr = [];
      arr.push('foo');
      arr.push('bar');
      expect(arr[0]).to.equal('foo');
      expect(arr[1]).to.equal('bar');
    })

    it('it should return the length', function () {
      var arr = [];
      var n = arr.push('foo');
      expect(n).to.equal(1);
      n = arr.push('bar');
      expect(n).to.equal(2);
    })

    describe('with many arguments', function () {
      it('it should add the values', function () {
        var arr = [];
        arr.push('foo', 'bar');
        expect(arr[0]).to.equal('foo');
        expect(arr[1]).to.equal('bar');
      })
    })
  })

  describe('.unshift()', function () {
    it('it should prepend a value', function () {
      var arr = [1, 2, 3];
      arr.unshift('foo');
      expect(arr[0]).to.equal('foo');
      expect(arr[1]).to.equal(1);
    })

    it('it should return the length', function () {
      var arr = [];
      var n = arr.unshift('foo');
      expect(n).to.equal(1);
      n = arr.unshift('bar');
      expect(n).to.equal(2);
    })

    describe('with many arguments', function () {
      it('it should add the values', function () {
        var arr = [];
        arr.unshift('foo', 'bar');
        expect(arr[0]).to.equal('foo');
        expect(arr[1]).to.equal('bar');
      })
    })
  })

  describe('.pop()', function () {
    it('it should remove and return the last value', function () {
      var arr = [1, 2, 3];
      expect(arr.pop()).to.equal(3);
      expect(arr.pop()).to.equal(2);
      expect(arr).to.have.length(1);
    })
  })

  describe('.shift()', function () {
    it('it should remove and return the first value', function () {
      var arr = [1, 2, 3];
      expect(arr.shift()).to.equal(1);
      expect(arr.shift()).to.equal(2);
      expect(arr).to.have.length(1);
    })
  })
})

Express examples

//testing a res.status 
var express = require('../')
  , request = require('supertest');

describe('res', function(){
  describe('.status(code)', function(){
    it('it should set the response .statusCode', function(done){
      var app = express();

      app.use(function(req, res){
        res.status(201).end('Created');
      });

      request(app)
      .get('/')
      .expect('Created')
      .expect(201, done);
    })
  })
})

Connect examples

//testing an app.listen
var assert = require('assert')
var connect = require('..');
var request = require('supertest');

describe('app.listen()', function(){
  it('it should wrap in an http.Server', function(done){
    var app = connect();

    app.use(function(req, res){
      res.end();
    });

    var server = app.listen(0, function () {
      assert.ok(server)
      request(server)
        .get('/')
        .expect(200, function (err) {
          server.close(function () {
            done(err)
          })
        })
    });
  });
});

SuperAgent examples

//form testing
'use strict';

const request = require('../support/client');
const setup = require('../support/setup');

const base = setup.uri;
const assert = require('assert');

describe('Merging objects', () => {
  it("Do not mix JSON and Buffer", () => {
    assert.throws(() => {
      request
        .post('/echo')
        .send(Buffer.from('some buffer'))
        .send({ allowed: false });
    });
  });
});

describe('req.send(String)', () => {
  it('it should default to "form"', done => {
    request
      .post(`${base}/echo`)
      .send('user[name]=tj')
      .send('user[email][email protected]')
      .end((err, res) => {
        res.header['content-type'].should.equal(
          'application/x-www-form-urlencoded'
        );
        res.body.should.eql({
          user: { name: 'tj', email: '[email protected]' }
        });
        done();
      });
  });
});

describe('res.body', () => {
  describe('application/x-www-form-urlencoded', () => {
    it('it should parse the body', done => {
      request.get(`${base}/form-data`).end((err, res) => {
        res.text.should.equal('pet[name]=manny');
        res.body.should.eql({ pet: { name: 'manny' } });
        done();
      });
    });
  });
});

WebSocket.io

//test for a websocket

/**
 * Test dependencies.
 */

var ws = require('../lib/websocket.io')
  , http = require('http')

/**
 * Tests.
 */

describe('websocket.io', function () {

  it('must expose version number', function () {
    ws.version.should.match(/[0-9]+\.[0-9]+\.[0-9]+/);
  });

  it('has to expose public constructors', function () {
    ws.Socket.should.be.a('function');
    ws.Server.should.be.a('function');
    ws.protocols.drafts.should.be.a('function');
    ws.protocols['7'].should.be.a('function');
    ws.protocols['8'].should.be.a('function');
    ws.protocols['13'].should.be.a('function');
  });

  it('must connect', function (done) {
    listen(function (addr, server) {
      var cl = client(addr);
      cl.on('open', function () {
        cl.close();
        server.close();
        done();
      });
    });
  });

  it('has to handle upgrade requests of a normal http server', function (done) {
    var httpServer = http.createServer(function (req, res) {
      res.writeHead(200);
      res.end('Hello World');
    })

    var server = ws.attach(httpServer);

    httpServer.listen(function (err) {
      if (err) throw err;

      var addr = httpServer.address();

      http.get({ host: addr.address, port: addr.port }, function (res) {
        res.on('data', function (data) {
          data.toString().should.equal('Hello World');

          var cl = client(addr);
          cl.on('open', function () {
            cl.close();
            httpServer.close();
            done();
          });
        });
      });
    });
  });

  it('has to listen on a port', function (done) {
    var server = ws.listen(null, function () {
      var addr = server.httpServer.address();
	
      http.get({ host: addr.address, port: addr.port }, function (res) {
        res.statusCode.should.equal(501);
        res.on('data', function (data) {
          data.toString().should.equal('Not Implemented');

          var cl = client(addr);
          cl.on('open', function () {
            cl.close();
            server.httpServer.close();
            done();
          });
        });
      });
    });
  });

});