The document outlines the principles and practices of Behavior Driven Development (BDD) using Jasmine, a BDD framework for testing JavaScript. It covers key concepts such as TDD, BDD cycles, installation, implementation, and terminology, along with examples and specifications for writing tests. Additionally, it discusses the use of spies and mocks in testing and provides resources for further learning.

1. BDD - Jasmine

2. Agenda
• Need of TDD/BDD
• Steps to BDD
• Familiarize terminology
• Installation
• Executing jasmine
• Write tests in jasmine
• What next?

3. TDD
• Involves writing tests before writing the code
being tested
• Write a small test first (at this point of time no
code being written!)
• Run the test (obviously, it fails!)
• Now make the test pass (well write some code)
• Observe the design, refactor

4. TDD - Challenges
• As the code size increases more refactor
becomes critical
• Since most of the time the features are not pre-
determined reviewing/refactoring does prove as
time consuming and becomes expensive

5. So what next???
• In real time objects are the carriers
• They extend the behavior of classes
• This would be mean, “what an object does is
significantly more important!”
• It’s all behavior

6. BDD
• Behaviour Driven Development is an Agile
development process that comprises aspects of
– Acceptance Test Driven Planning,
– Domain Driven Design
– Test Driven Development

7. BDD
• BDD puts the focus on Behavior rather than
structure
• Examples
– User inputting values
– Awaiting for the feedback
– Calculations/logic
• It’s all behavior

8. BDD Triad
• For better communication across the levels
(Business analysts, Developers, Testers) in
software development we narrate/describe the
logical chunks as scenarios
• Given/When/Then – called as BDD triad

9. BDD Cycle

10. Jasmine

11. Jasmine
• It’s a BDD Framework for testing JavaScript
• Does not depend on other frameworks
• Does not require a DOM
• Clean & Obvious syntax
• Influenced by Rspec, JSSpec, Jspec
• Available as stand-alone, ruby gem, Node.js module, as
Maven plugin

12. Principles
• Should not be tied to any browser, framework,
platform or host language
• Should have idiomatic and unsurprising syntax
• Should work wherever JavaScript runs
• Should play well with IDE’s

13. Goals
• It should encourage good testing practices
• It should be simple to get start with
• It should integrate easily with continuous build
systems

14. Terminology
•Specs
•Suites
•describe
•it
•expect
•matchers
•mocks
•spies

15. Installation
•Required files/structure
•Download stand alone zip file include the lib files
<script type="text/javascript" src="lib/jasmine-1.0.0.rc1/jasmine.js"></script>
<script type="text/javascript" src="lib/jasmine-1.0.0.rc1/jasmine-html.js"></script>
•Include styles as well
<link rel="stylesheet" type="text/css" href="lib/jasmine-1.0.0.rc1/jasmine.css">

16. Implementation/File structure
•jasmine-example/
• lib/
• jasmine-1.3.1/jasmine.js
• jasmine-1.3.1/jasmine-html.js
• jasmine-1.0.0.rc1/jasmine.css
• specs/
• SpecHelper.js
• BasicMathSpec.js
• scripts/
• BasicMath.js

17. http://tryjasmine.com/

18. describe ... it
describe accepts a
string or class.
Helps in
organizing specs
it is what describes the
spec. It optionally
takes a string
// Jasmine
describe “Calculate”, function() {
describe “#Add”, function(){
it “should give sum”, function(){
-----
-----
};
});
});

19. Filters
// Jasmine
var calc;
beforeEach(function(){
calc = new Calculator();
});
afterEach(function(){
calc.reset();
});
Pretty handy to create data
for each test
before runs the specified
block before each test.
after runs the specified block
after each test.

20. Expectations
//Jasmine
it (“should return the sum”, function(){
calc = new Calculator();
expect(calc.Add(4,5).toEqual(9));
expect(calc.Add(4,4).not.toEqual(9));
});

21. http://tryjasmine.com/

22. Specs - variables
Spec -
describe('panda',function(){
it('is happy',function(){
expect(panda).toBe('happy');
});
});
JavaScript
panda = “happy”;

23. Specs - variables
Spec -
describe('panda',function(){
it('is happy',function(){
expect(panda).toBe('happy');
});
});
JavaScript
panda = “happy”;

24. Specs - functions
Spec
describe('Hello World function',function(){
it('just prints a string',function(){
expect(helloWorld()).toEqual("Hello world!");
});
});
JavaScript
function helloWorld(){
return "Hello world!";
}

25. Specs –matchers
Spec
describe('Hello World function',function(){
it('just prints a string',function(){
expect(helloWorld()).toContain("world!");
});
});
JavaScript
function helloWorld(){
return "Hello world!";
}

26. Specs –Custom matchers
Spec
describe('Hello world', function() {
beforeEach(function() {
this.addMatchers({
toBeDivisibleByTwo: function() {
return (this.actual % 2) === 0;
}
});
});
it('is divisible by 2', function() {
expect(guessANumber()).toBeDivisibleByTwo();
});
});

27. Spy
• Spy are handy in tracking down the usage of dependent or
functions that are being invoked by other functions
• Take a scenario, where on the website I would like to wish the
user like Hi, Hello along with salutation Mr, Ms, Mrs
• Say I have a simple function greet() which returns plain string
• Another function which returns the salutation()
• spyOn(obj, 'method')
• expect(obj.method).toHaveBeenCalled()

28. Spy - usage
• spyOn(obj, 'method')
• expect(obj.method).toHaveBeenCalled()
• expect(obj.method).toHaveBeenCalled(“Hello”,”Mr”)
• obj.method.callCount

29. Specs – Spy
describe("User", function() {
it("calls the salutation function", function() {
var visitor = new User();
spyOn(visitor, "greetUser");
visitor.greetUser("Hello");
expect(visitor.greetUser).toHaveBeenCalled();
});
});

30. Specs – Functions
User = function(){};
User.prototype.greetUser = function(salutation){
return this.sayHello() + "" + salutation;
}
User.prototype.sayHello = function(){
return "Hello";
}

31. DEMO

32. What next?
• Spies
• Mocking/Faking
• coffee-script
• jasmine-jquery
• jasmine-fixture
• jasmine-stealth

33. Thanks
References:
http://blog.bandzarewicz.com/blog/2012/03/08/jasmine-cheat-sheet/
http://evanhahn.com/how-do-i-jasmine/
http://tobyho.com/2011/12/15/jasmine-spy-cheatsheet/
https://github.com/pivotal/jasmine/wiki/Spies