Why Write Tests?

Time

• Less breaking code
• More Automation
• Free Documentation

Confidence

• Adding functionality
• Refactoring
• Accepting changes

Other Reasons

• Learn codebase
• Spec out APIs
• Meeting customer specs

Terminology

TDD / BDD

Runners and Harnesses

Testing Terms

Fixtures

     Consistent source of data

Testing Terms

Modules

     Pattern for grouping code into components

Testing Terms

Linting

     Detects errors and potential problems

Testing Terms

Automation Terms

Libraries

Frameworks

• Mocha
• Jasmine
• TAP
• QUnit

Assertions

• Expect.js
• Should.js
• Chai

Utilities

• Sinon - Spies and Stubs
• Istanbul - Code Coverage
• Phantom.js - Headless Webkit
• Karma - Browser Runner

Example Layout

TAP

test("make sure the thingie is a thing", function (t) {
  t.equal(thingie, "thing", "thingie should be thing");
  t.deepEqual(array, ["foo", "bar"], "array has foo and bar elements");
  t.deepEqual(object, {foo: 42}, "object has foo property");
  t.type(thingie, "string", "type of thingie is string");
  t.ok(true, "this is always true");
  t.notOk(false, "this is never true");

  t.test("a child test", function (t) {
    t.equal(this, superEasy, "right!?");
  });
});

Mocha (BDD)

var expect = require('chai').expect;

describe('User', function(){
  describe('save', function(){
    it('should be a function', function () {
      expect(User).to.have.property('save');
      expect(User.save).to.be.a('function');
    });

    it('should save without error', function(done){
      var user = new User('Luna');
      user.save(function(err){
        expect(err).to.be.a('null');
        expect(user.name).to.be('Luna');

        done();
      });
    });
  });
});

Jasmine (BDD)

describe('User', function(){
  describe('save', function(){
    it('should be a function', function () {
      expect('save' in User).toBe(true);
      expect(typeof User.save).toBe('function');
    });

    it('should save without error', function(done){
      var user = new User('Luna');
      user.save(function(err){
        expect(err).toBeNull('null');
        expect(user.name).toBe('Luna');

        done();
      });
    });
  });
});

Types of Tests

Test a specific, isolated unit of code

Unit Tests

Requirements

• Harness
• Environment

Example Output

Example Output

Example Output

Test the integration of system components

Integration Tests

Requirements

• Harness
• Environment

Example Output

Example Output

Unit Tests

Test a specific, isolated unit of code

Integration Tests

Test the integration of components

• Mocks, stubs, spies
• Modules, DI
• Code Separation

• User Interaction
• Component Separation

Workflow

1. Write some code
2. Write some tests

1. Write some tests
2. Write some code

Getting Started

Test Execution

• Terminal
• Browser
• Selenium
• Sauce Labs
• Browser Stack

Test Automation

• Build process
• Pre-commit hooks

Automatic Local Execution

Continuous Integration

Automatic Remote Execution

• Jenkins
• Travis CI
• Codeship

Continuous Deployment

Testing Tips

Keep it small

Keep it small

Keep it modular

• AMD / CommonJS / ES6
• Easier separation
• Easier inclusion in tests

Keep it modular

Keep it private

• Don't sweat about private methods
• Expose what you need to test

Keep it private

Keep it covered

Keep it covered

Recap

• Small code
• Modular code
• Don't over-think private functions
• Use coverage reports

Write Some Test

Some tests > No tests

Thanks!