Front end unit testing using jasmine
1 like1,214 views
This document discusses unit testing JavaScript code using the Jasmine testing framework. It provides an overview of unit testing, behavior driven development (BDD) and how Jasmine supports BDD style testing. It demonstrates how to set up Jasmine, create test suites and specs, use matchers for expectations, and work with spies and async code. The document also discusses how to integrate Jasmine with Karma, a test runner that allows executing tests across multiple browsers.
Front end unit testing using jasmine
- 1. SELA DEVELOPER PRACTICE Gil Fink Front-End Unit Testing Using Jasmine
- 2. Agenda Unit Testing in JavaScript? Behavior Driven Development Jasmine Jasmine and Karma
- 3. Life Without Unit Testing
- 4. Why Unit Testing? Tests Act as safety net when you modify your code Increase your confidence in your code Encourage good design Help to detect bugs in early stages of the project Serve as live documentation
- 5. Unit Testing in JavaScript? JavaScript is everywhere Browsers Servers Operation Systems Databases Mobile Devices You are doing it in any other language…
- 6. Behavior Driven Development (BDD)
- 7. BDD – Cont. In BDD you describe your code tell the test what it (the code) should do expect your code to do something The user can read the output and understand it //suite describe ('', function(){ //test it ('', function(){ //expectation expect(); )}; });
- 8. Jasmine A JavaScript BDD framework Can be downloaded from: http://jasmine.github.io/
- 9. Setting Up The Environment Download Jasmine or use a package manager such as Bower or Nuget Create a Spec (Test) Runner file Responsible to run all the unit tests Runs in the browser Create the Unit Test files Jasmine can also run headless Without a browser context
- 11. Jasmine Tests Suites First create a Suite which is a container of Specs Use the describe function describe("Suite Name", function() { // Put here your tests });
- 12. Jasmine Tests A Spec (Test) is defined by calling the it function Receives a spec name and a spec callback function Contains expectations that test the state of the code describe("Suite Name", function() { it("a spec with one expectation", function() { // create the spec body }); });
- 13. Expectations Expectations are assertions that can be either true or false Use the expect function within a spec to declare an expectation Receives the actual value to test as parameter Include fluent API for matchers A Matcher is a Boolean comparison between the actual value and the expected value
- 14. Matchers it("matchers", function() { var a = 12; var b = a; var c = function () { } expect(a).toBe(b); expect(a).not.toBe(null); expect(a).toEqual(12); expect(null).toBeNull(); expect(c).not.toThrow(); });
- 15. Demo Creating Suites and Specs
- 16. Setup and Teardown Jasmine includes beforeEach – runs before each test afterEach – runs after each test Should exists inside a test suite
- 17. Setup and Teardown Example describe("A suite", function() { var index = 0; beforeEach(function() { index += 1; }); afterEach(function() { index = 0; }); it("a spec", function() { expect(index).toEqual(1); }); });
- 18. Demo Using Setup and Teardown
- 19. Working with Spies A spy is a test double object It replaces the real implementation and fake its behavior Use spyOn, createSpy and createSpyObj functions
- 21. Jasmine Async Support Jasmine enables to test async code Calls to beforeEach, it, and afterEach take an additional done function beforeEach(function(done) { setTimeout(function() { value = 0; done(); }, 1); }); // spec will not start until the done in beforeEach is called it("should support async execution", function(done) { value++; expect(value).toBeGreaterThan(0); done(); });
- 22. Demo Working with Async Functions
- 23. Jasmine and Karma Karma is a test runner for JavaScript Executes JavaScript code in multiple browser instances Makes BDD/TDD development easier Can use any JavaScript testing library In this session we will use Jasmine
- 25. Questions
- 26. Summary Unit Tests are an important part of any development process Jasmine library can help you to test your JavaScript code Add tests to your JavaScript code!
- 27. Resources Session slide deck – http://slidesha.re/1mO08Mq Jasmine – http://jasmine.github.io/ My Website – http://www.gilfink.net Follow me on Twitter – @gilfink