How and why to write tests in javascript. Jasmine, Testacular.

1. Dev in Bahia 1º First
Technical Meeting

2. What is Dev In Bahia ?
• Borned in 2012 through the #horaextra.
• Has the vision to transform our local IT Market in a better
place to work and to develop ourselves as IT Professionals.
• What we do ?
• Promote Events, Discussions, User groups and so on.

3. Technical Meetings
• We are trying to promete one since last year.
• Prevented by:
• Place
• People
• Schedule
• We want to promote a technical meeting once or twice a
month.
• Tech Talk + Coding Dojo
• Before each meeting, people will send talk suggestions and we
are going to vote to choose.

4. Who is Paulo Ortins ?
• Developer at Inteligência Digital
• Masters Student at UFBA ( Software Engineering)
• Blogger at www.pauloortins.com
• Newsletter Curater at dotnetpills.apphb.com
• Joined in the community in 2011
• Polyglot Programmer
• Founded Dev In Bahia and #horaextra
Twitter: @pauloortins
Github: pauloortins

5. 1º Technical Meeting
• How create tests using Javascript ?

6. A test overview
• Monkey Tests
• Unit Tests
• End-to-End Tests

7. Monkey Tests

8. But Requirements Change

9. You do it again

10. Monkey Test [2]

11. But Requirements Change[2]

12. Monkey Test Division

13. Problems with Monkey Tests
• Low Reliability, people aren’t machines, they work has
variance.
• Expensive, people have to test the software everytime
something changes.

14. Super Kent Beck

15. Automated Tests
• Tests should be automated.
• Functionality are done if, and only if, there are automated
tests covering them.

16. Unit Tests
• Tests only a piece of code.
• Provide instantly feedback about our software.
• Help to improve code design.

17. Example
function isBetweenFiveAndTen(number) {
var isGreaterThanFive = number > 5;
var isLesserThanTen = number < 10;
return isGreaterThanFive && isLesserThanTen;
}
Input Output
5 False
6 True
7 True
10 False

18. End-to-end Tests
• Tests simulate a monkey test, covering browser interaction,
database access, business rules.
• Slower than unit tests.
• Let me show a example using Selenium WebDriver

19. Javascript
• Javascript is rising.
• Web more interactive and responsive.
• Applications like Facebook and Gmail.
• Web Apps ( PhoneGap, Ext.js, jquery mobile)

20. Unit tests in Javascript
• There are several options to create unit tests in Javascript:
• Qunit
• Mocha
• Jasmine

21. Jasmine
• Created due the dissatisfaction existing framworks by
PivotalLabs.
• Small library
• Easy to use

22. Suites
describe("A suite", function() {
it("contains spec with an expectation", function() {
expect(true).toBe(true);
});
});
• Describe, name a test suite ou a set test.
• It, describe the test name.

23. Expectations
describe("The 'toBe' matcher compares with ===", function() {
it("and has a positive case ", function() {
expect(true).toBe(true);
});
it("and can have a negative case", function() {
expect(false).not.toBe(true);
});
});
• Comparisons made through matchers, who are predefined
functions who receives a value (actual) and compares with the
expected value.
• A lot of matchers are included.

24. Matchers
describe("The 'toEqual' matcher", function() {
it("works for simple literals and variables", function() {
var a = 12;
expect(a).toEqual(12);
});
it("should work for objects", function() {
var foo = {
a: 12,
b: 34
};
var bar = {
a: 12,
b: 34
};
expect(foo).toEqual(bar);
});
});

25. Matchers
it("The 'toMatch' matcher is for regular expressions", function() {
var message = 'foo bar baz';
expect(message).toMatch(/bar/);
expect(message).toMatch('bar');
expect(message).not.toMatch(/quux/);
});

26. Matchers
it("The 'toBeDefined' matcher compares against `undefined`",
function() {
var a = {
foo: 'foo'
};
expect(a.foo).toBeDefined();
expect(a.bar).not.toBeDefined();
});

27. Matchers
it("The 'toBeNull' matcher compares against null", function() {
var a = null;
var foo = 'foo';
expect(null).toBeNull();
expect(a).toBeNull();
expect(foo).not.toBeNull();
});

28. Matchers
it("The 'toBeTruthy' matcher is for boolean casting testing", function()
{
var a, foo = 'foo';
expect(foo).toBeTruthy();
expect(a).not.toBeTruthy();
});
it("The 'toBeFalsy' matcher is for boolean casting testing", function() {
var a, foo = 'foo';
expect(a).toBeFalsy();
expect(foo).not.toBeFalsy();
});

29. Matchers
it("The 'toContain' matcher is for finding an item in an Array",
function() {
var a = ['foo', 'bar', 'baz'];
expect(a).toContain('bar');
expect(a).not.toContain('quux');
});

30. Matchers
it("The 'toBeLessThan' matcher is for mathematical comparisons", function() {
var pi = 3.1415926, e = 2.78;
expect(e).toBeLessThan(pi);
expect(pi).not.toBeLessThan(e);
});
it("The 'toBeGreaterThan' is for mathematical comparisons", function() {
var pi = 3.1415926, e = 2.78;
expect(pi).toBeGreaterThan(e);
expect(e).not.toBeGreaterThan(pi);
});
it("The 'toBeCloseTo' matcher is for precision math comparison", function() {
var pi = 3.1415926, e = 2.78;
expect(pi).not.toBeCloseTo(e, 2);
expect(pi).toBeCloseTo(e, 0);
});

31. Matchers
it("The 'toThrow' matcher is for testing if a function throws an
exception", function() {
var foo = function() {
return 1 + 2;
};
var bar = function() {
return a + 1;
};
expect(foo).not.toThrow();
expect(bar).toThrow();
});

32. Custom Matchers
beforeEach(function() {
this.addMatchers({
isEven: function(number) {
return number % 2 === 0;
}
});
});

33. Setup/Teardown
describe("A spec (with setup and tear-down)", function() {
var foo;
beforeEach(function() {
foo = 0;
foo += 1;
});
afterEach(function() {
foo = 0;
});
it("is just a function, so it can contain any code", function() {
expect(foo).toEqual(1);
});
it("can have more than one expectation", function() {
expect(foo).toEqual(1);
expect(true).toEqual(true);
});
});

34. Let’s play with Jasmine
• Site
• Tutorial
• Standalone Version

35. Testacular/Karma
• Created by Google to test Angular.js
• Runs on top of Node.js
• Watch our JS files to detect changes and rerun the tests

36. Thank you!