How do I write Testable Javascript?

* 
* Who Am I?
* State of the Room?
* Ways to test Javascript?
* Different Testing Environments?
* Overview of Testing Tools
* Using Testing in your Workflow
* Spaghetti Javascript
* Refactor Spaghetti into Testable Javascript
* Installing Jasmine + Live Demo

* 
* Gavin Pickin – developing Web Apps since late 90s
* What else do you need to know?
* Blog - http://www.gpickin.com
* Twitter – http://twitter.com/gpickin
* Github - https://github.com/gpickin
* Lets get on with the show.

* 
* A few questions for you guys
* If you have arms, use them.

* 
* Click around in the browser yourself
* Setup Selenium / Web Driver to click
around for you
* Structured Programmatic Tests

* 
* Black/White Box
* Unit Testing
* Integration Testing
* Functional Tests
* System Tests
* End to End Tests
* Sanity Testing
* Regression Test
* Acceptance Tests
* Load Testing
* Stress Test
* Performance Tests
* Usability Tests
* + More

* 
* Integration Tests several of the
pieces together
* Most of the types of tests are
variations of an Integration Test
* Can include mocks but can full end
to end tests including DB / APIs

* 
“unit testing is a software verification
and validation method in which a
programmer tests if individual units of
source code are fit for use. A unit is the
smallest testable part of an application”
- wikipedia

* 
* Can improve code quality -> quick error
discovery
* Code confidence via immediate
verification
* Can expose high coupling
* Will encourage refactoring to produce >
testable code
* Remember: Testing is all about behavior
and expectations

* 
* TDD = Test Driven Development
* Write Tests
* Run them and they Fail
* Write Functions to Fulfill the Tests
* Tests should pass
* Refactor in confidence
* Test focus on Functionality

* 
* BDD = Behavior Driven Development
Actually similar to TDD except:
* Focuses on Behavior and Specifications
* Specs (tests) are fluent and readable
* Readability makes them great for all levels of
testing in the organization
* Hard to find TDD examples in JS that are not
using BDD describe and it blocks

* 
Test( ‘Email address must not be
blank’, function(){
notEqual(email, “”, "failed");
});

* 
Describe( ‘Email Address’,
function(){
It(‘should not be blank’, function(){
expect(email).not.toBe(“”);
});
});

* 
expect(true).toBe(true);

* 
expect(true).not.toBe(true);

* 
expect(a).not.toBe(null);
expect(a).toEqual(12);
expect(message).toMatch(/bar/);
expect(message).toMatch("bar");
expect(message).not.toMatch(/quux/);
expect(a.foo).toBeDefined();
expect(a.bar).not.toBeDefined();

* 
NodeJS - CLI In the Browser

* 
* There are a few choices

* 
* Jasmine, Mocha and QUnit

* 
* Jasmine comes ready to go out of the box
* Fluent Syntax – BDD Style
* Includes lots of matchers
* Has spies included
* Very popular, lots of support
* Angular uses Jasmine with Karma (CLI)
* Headless running and plays well with CI
servers

* 
* Async testing in 1.3 can be a
headache
* Expects *spec.js suffix for test files
* This can be modified depending on
how you are running the tests

* 
describe("Hello world function", function() {
it(”contains the word world", function() {
expect(helloWorld()).toContain("world");
});
});

* 
* Simple Setup
* Simple Async testing
* Works great with other Assertion
libraries like Chai ( not included )
* Solid Support with CI Servers, with
Plugins for others
* Opinion says Mocha blazing the trail for
new features

* 
* Requires other Libraries for key features
* No Assertion Library included
* No Mocking / Spied included
* Need to create the runner manually
* Newer to the game so not as popular or
supported as others but gaining traction.

* 
var expect = require('chai').expect;
describe(’Hello World Function', function(){
it('should contain the word world', function(){
expect(helloWorld()).to.contain(’world');
})
})

* 
* The oldest of the main testing frameworks
* Is popular due to use in jQuery and age
* Ember’s default Unit testing Framework

* 
* Development slowed down since
2013 (but still under development)
* Syntax – No BDD style
* Assertion libraries – limited
matchers

* 
QUnit.test( "ok test", function( assert ) {
assert.ok( true, "true succeeds" );
assert.ok( "non-empty", "non-empty string
succeeds" );
assert.ok( false, "false fails" );
assert.ok( 0, "0 fails" );
assert.ok( NaN, "NaN fails" );
assert.ok( "", "empty string fails" );
assert.ok( null, "null fails" );
assert.ok( undefined, "undefined fails" );
});

* 
Photo Credit – Kombination
http://www.kombination.co.za/wp-content/uploads/2012/10/baby_w_spaghetti_mess_4987941.jpg

* 
* Things to refactor to make your code testable
* Code should not be one big chunk of
Javascript in onReady()
* Deep nested callbacks & Anon functions
cannot easily be singled out and tested
* Remove Tight Coupling – DOM access for
example

* 
* Lets look at some code
* This isn’t BEST PRACTICE, its BETTER
PRACTICE than you were doing
* Its not really refactoring if you don’t have
tests, its
“moving code and asking for trouble”

* 
var personObjLit = {
ssn: ’xxxxxxxx',
age: '35',
name: 'Gavin Pickin',
getAge: function(){
return this.age;
},
getName: function() {
return this.name;
}
};

* 
var personObjLit2 = function() {
ssn = ’xxxxxxx';
age = '35';
name = 'Gavin Pickin’;
return {
getAge: function(){
return age;
},
getName: function() {
return name;
}
};
};

* 
* Using HTML Test Runners
* Keep a Browser open
* F5 refresh tests

* 
* Run Jasmine – manual
* Run tests at the end of each section of work
* Run Grunt-Watch – automatic
* Runs Jasmine on every file change
* Grunt can run other tasks as well,
minification etc

* 
* Browser Views
* Eclipse allows you to open files in
web view – uses HTML Runner
* Run Jasmine / Grunt / Karma in IDE
Console
* Easy to setup – See Demo– Sublime Text 2

* 
* Install / Run Jasmine Standalone for Browser
* Install / Run Jasmine with NodeJs
* Install/ Run Jasmine with Grunt Watch
* Install / Run Grunt Watch inside Sublime Text 2

* 
Download standalone package from Github (I have 2.1.3)
https://github.com/jasmine/jasmine/tree/master/dist
Unzip into your /tests folder
Run /tests/SpecRunner.html to see example tests

* 
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Jasmine Spec Runner v2.1.3</title>
<link rel="shortcut icon" type="image/png" href="lib/jasmine-2.1.3/jasmine_favicon.png">
<link rel="stylesheet" href="lib/jasmine-2.1.3/jasmine.css”>
<script src="lib/jasmine-2.1.3/jasmine.js"></script>
<script src="lib/jasmine-2.1.3/jasmine-html.js"></script>
<script src="lib/jasmine-2.1.3/boot.js"></script>

<script src="../js/services/loginService.js"></script>

<script src="spec/loginServiceSpec.js"></script>
</head>
<body>
</body>
</html>

* 
Assuming you have NodeJs Installed… install Jasmine
$ npm install jasmine
jasmine@2.2.1 node_modules/jasmine
├── exit@0.1.2
├── jasmine-core@2.2.0
└── glob@3.2.11 (inherits@2.0.1, minimatch@0.3.0)

* 
Once Jasmine is installed in your project
$ Jasmine init

* 
Edit Jasmine.json to update Locations for Spec Files and Helper Files
{
"spec_dir": "spec",
"spec_files": [
"**/*[sS]pec.js"
],
"helpers": [
"helpers/**/*.js"
]
}

* 
$ Jasmine
Started
F
Failures:
1) A suite contains spec with an expectation
Message:
Expected true to be false.
Stack:
Error: Expected true to be false.
at Object.<anonymous> (/Users/gavinpickin/Dropbox/Apps/
testApp/www/spec/test_spec.js:3:18)
1 spec, 1 failure
Finished in 0.009 seconds

* 
* Jasmine-Node is great for Node
* Jasmine Node doesn’t have a headless browser
* Hard to test Browser code
* So what should I use?

* 
* Install Grunt
npm install grunt
* Install Grunt – Jasmine
npm install grunt-contrib-jasmine
* Install Grunt – Watch
npm install grunt-contrib-watch
* Note: On Mac, I also needed to install Grunt CLI
npm install –g grunt-cli

* 
// gruntfile.js - https://gist.github.com/gpickin/1e1e7902d1d3676d23c5
module.exports = function (grunt) {
grunt.initConfig({
pkg: grunt.file.readJSON('node_modules/grunt/package.json'),
jasmine: {
all: {
src: ['js/*.js' ],
options: {
//'vendor': ['path/to/vendor/libs/*.js'],
'specs': ['specs/*.js' ]
}
}
},

* 
// gruntfile.js part 2
watch: {
js: {
files: [
'js/*.js',
'specs/*.js',
],
tasks: ['jasmine:all']
}
}
});

* 
// gruntfile.js part 3
grunt.loadNpmTasks('grunt-contrib-jasmine');
grunt.loadNpmTasks('grunt-contrib-watch');
};

* 
describe("A suite", function() {
it("contains spec with an expectation", function() {
});
});

* 
* Install PackageControl into Sublime Text
* Install Grunt from PackageControl
* https://packagecontrol.io/packages/Grunt
* Update Grunt Sublime Settings for paths
{
"exec_args": { "path": "/bin:/usr/bin:/usr/local/bin” }
}
* Then Command Shift P – grunt

* 
* Any questions?
* Come check out my Cordova Hooks session and see
how you can run Unit Tests (and much more)
whenever you’re preparing a build for your cordova
app.

How do I write Testable Javascript?

More Related Content

What's hot (19)

Viewers also liked (8)

Similar to How do I write Testable Javascript? (20)

More from Gavin Pickin (8)

Recently uploaded (20)

How do I write Testable Javascript?