Jasmine - why JS tests don't smell fishy

3,831 views
3,553 views

Published on

Presentation about Jasmine - BDD

Published in: Technology, Education
4 Comments
8 Likes
Statistics
Notes
No Downloads
Views
Total views
3,831
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
53
Comments
4
Likes
8
Embeds 0
No embeds

No notes for slide

Jasmine - why JS tests don't smell fishy

  1. 1. 1 JASMINEWhy JavaScript tests don’t smell fishy?
  2. 2. WHAT I WILL TALK ABOUT: 2 • What is Unit Testing • Solution: Jasmine - whole syntax with examples • WebStorm goodies • Benefits of Units Tests • Why people don’t test JavaScript? • Test Driven Development, Behavior Driven Development
  3. 3. WHY PEOPLE DON’T TEST JAVASCRIPT ? • project not big enough • project too complex • asynchronous XHR requests • DOM manipulation • too many browsers, platforms, devices 3
  4. 4. UNIT TESTING is a program (test case or test specification) that isolates and tests small and specific functional unit of code. Test one small functionality per suite. Not too many things at one time. Remember! It impossible to write test for every case - try to cover every reasonable case, remember about corner cases 4 GOOD PRACTICES
  5. 5. BENEFITS OF USING JAVASCRIPT TESTS 5 • QA phase is cheaper - you will uncover bugs earlier • Creates great documentation • As a developer you will write better code • Shows that JS should work as was designed • Quick and easy to run - try to do it with manual testing • Runs the same every time
  6. 6. TDD & BDD Behavior Driven Development: agile software development technique testing from business value perspective, why some code is necessary and what its goal is 6 Test Driven Development: write tests against specification, watch your test fail, write some code, test, refactor, test-fix-implement
  7. 7. TDD vs BDD Example: 10 sorting methods TDD: one test per one method - focused on „how” each method works BDD: one test per all methods - focused on the goal give an array, sort, result 7
  8. 8. JASMINE MATCHERS - EQUALITY expect(true).toEqual(true); expect({}).toEqual({}); 8 toEqual
  9. 9. JASMINE MATCHERS - IDENTITY var spot = { species: "Border Collie" }; var cosmo = { species: "Border Collie" }; // success; equivalent expect(spot).toEqual(cosmo); // failure; not the same object expect(spot).toBe(cosmo); // success; the same value expect(2).toBe(2); toBe checks if two things are the same value and type, using === Primitive Types vs Reference Types primitive will be give you true, reference will give you false 9
  10. 10. JASMINE MATCHERS - BOOLEAN expect(true).toBeTruthy(); expect(12).toBeTruthy(); expect({}).toBeTruthy(); expect(false).toBeFalsy(); expect(null).toBeFalsy(); expect("").toBeFalsy(); //false, 0, “”, undefinded, null, NaN toBeTruthy toBeFalsy10
  11. 11. JASMINE MATCHERS - NEGATION expect(this).not.toEqual(that); expect({}).not.toBe([]); not11
  12. 12. JASMINE MATCHERS - CONTAINS expect([1, 2, 3, 4]).toContain(3); expect(["Jasmine", "Qunit", "Mocha", "Casper"]).toContain("Jasmine"); expect("Rychu Peja to pener").toContain("pener"); var dog = { name: "Reksio" }; expect([ { name: "Dżeki" }, { name: "Max" }, { name: "Reksio" } ]).toContain(dog); toContain12
  13. 13. JASMINE MATCHERS - DEFINED OR UNDEFINED var somethingUndefined; expect("Hello!").toBeDefined(); // success expect(null).toBeDefined(); // success expect(somethingUndefined).toBeDefined(); // failure var somethingElseUndefined; expect(somethingElseUndefined).toBeUndefined(); // success expect(2013).toBeUndefined(); // failure expect(null).toBeUndefined(); // failure toBeDefined toBeUndefined13
  14. 14. JASMINE MATCHERS - NULLNESS expect(null).toBeNull(); // success expect(false).toBeNull(); // failure expect(somethingUndefined).toBeNull(); // failure //null is where the thing is known to exist, //but it's not known what the value is. toBeNull14
  15. 15. JASMINE MATCHERS - IS NaN expect(5).not.toBeNaN(); // success expect(0 / 0).toBeNaN(); // success expect(parseInt("hello")).toBeNaN(); // success /* This is different from JavaScript’s built-in isNaN function. The built-in isNaN will return true for many nonnumber types, such as nonnumeric strings, objects, and arrays. Jasmine’s will be positive only if it’s the NaN value. */ toBeNaN15
  16. 16. JASMINE MATCHERS - COMPARATORS expect(8).toBeGreaterThan(5); expect(5).toBeLessThan(12); expect("a").toBeLessThan("z"); // it works for strings toBeGreaterThan toBeLessThan16
  17. 17. JASMINE MATCHERS - NEARNESS expect(12.34).toBeCloseTo(12.3, 1); // success toBeCloseTo17
  18. 18. JASMINE MATCHERS - REGULAR EXPRESSIONS expect("some words").toMatch(/some/); // success toMatch18
  19. 19. JASMINE MATCHERS - ERROR THROWING var errorThrower = function () { throw new Error(); } expect(errorThrower).toThrow(); // success toThrow19
  20. 20. JASMINE - BEFORE AND AFTER TESTS var player, wallet; // remember about scope beforeEach( function () { player = new Player; }); afterEach( function () { wallet.empty(); // empty after each test }); beforeEach afterEach20
  21. 21. JASMINE MATCHERS - CUSTOM MATCHERS beforeEach( function () { this.addMatchers({ toBeLarge: function () { this.message = function () { return "Expected " + this.actual + " to be large"; }; return this.actual > 100; } }); }); expect(5).toBeLarge(); // failure expect(101).toBeLarge(); // success custom matchers21
  22. 22. JASMINE - NESTED SUITS describe("Expected ", function () { describe("something ", function () { it("should do something", function () { expect(2).toBe(2); }); }); }); 22 describe describe
  23. 23. JASMINE - SKIP THE TEST describe("Expected ", function () { xdescribe("something ", function () { xit("should do something", function () { expect(2).toBe(2); }); return; it("should do something else", function () { expect(3).toBe(3); }); }); }); 23 xit xdescribe return
  24. 24. JASMINE - SPIES var Dictionary = function() {}, Person = function() {}; Dictionary.prototype.hello = function () { return "hello"; }; Dictionary.prototype.world = function () { return "world"; }; Person.prototype.sayHelloWorld = function(dict) { return dict.hello() + " " + dict.world(); }; var dictionary = new Dictionary, person = new Person; person.sayHelloWorld(dictionary); // returns "hello world" describe("Person", function() { it('uses the dict to say "hello world"', function() { var dictionary = new Dictionary, person = new Person; // replace each function with a spy spyOn(dictionary, "hello"); spyOn(dictionary, "world"); person.sayHelloWorld(dictionary); // not possible without first spies expect(dictionary.hello).toHaveBeenCalled(); expect(dictionary.world).toHaveBeenCalled(); }); }); toHaveBeenCalled Often you test more than variable checks. Spy can pretend that he is a function or an object. 24
  25. 25. JASMINE - SPIES can call through the function describe("Person", function() { it('uses the dictionary to say "hello world"', function () { var dictionary = new Dictionary, person = new Person; spyOn(person, "sayHelloWorld"); // replace hello world function with a spy person.sayHelloWorld(dictionary); expect(person.sayHelloWorld).toHaveBeenCalledWith(dictionary); }); }); toHaveBeenCalledWith25
  26. 26. JASMINE - SPIES can return specific value it("spy can return specific value", function () { var dictionary = new Dictionary, person = new Person, result; spyOn(dictionary, "hello").andReturn("Witaj"); result = person.sayHelloWorld(dictionary); expect(result).toEqual("Witaj world"); }); andReturn26
  27. 27. JASMINE - SPIES can count its calls callCount it("can count calls of spy", function () { var dictionary = new Dictionary, spy; spy = spyOn(dictionary, "hello"); dictionary.hello(); expect(spy.callCount).toEqual(1); }); 27
  28. 28. JASMINE - SPIES can get recent arguments mostRecentCall.args it("can give you last arguments", function () { var dictionary = new Dictionary, person = new Person, spy; spy = spyOn(person, "sayHelloWorld"); person.sayHelloWorld("No siemano"); // remember arguments will be in array expect(spy.mostRecentCall.args).toEqual(["No siemano"]); }); 28
  29. 29. JASMINE - SPIES can get arguments of specific call argsForCall[index] it("can give you last arguments", function () { var dictionary = new Dictionary, person = new Person, spy; spy = spyOn(person, "sayHelloWorld"); person.sayHelloWorld("No siemano"); person.sayHelloWorld("Hejka"); // remember arguments will be in array and argForCall is also array expect(spy.argsForCall[1]).toEqual(["Hejka"]); }); 29
  30. 30. JASMINE - SPIES can call fake functions it("can call a fake function", function() { var fakeHello = function() { console.log("I’m a fake function"); return "hello"; }; var dictionary = new Dictionary(); spyOn(dictionary, "hello").andCallFake(fakeHello); dictionary.hello(); // does an log }); andCallFake30
  31. 31. JASMINE - SPIES can be created on its own it("can have a spy function", function() { var person = new Person(); person.getName = jasmine.createSpy("Name spy"); person.getName(); expect(person.getName).toHaveBeenCalled(); }); jasmine.createSpy31
  32. 32. 32 JASMINE - SPIES can chain actions person.getSecretAgentName = jasmine.createSpy("Name spy").andReturn("James Bond"); chaning
  33. 33. JASMINE - SPIES can be an object it("spy can be an object", function() { var player = jasmine.createSpyObj("player", ["hustle", "rap"]); player.hustle(); // magic to test }); jasmine.createSpyObj33
  34. 34. JASMINE - asynchronous - RUNS it("runnin’", function() { runs(function() { it("should do something", function () { expect(2).toBe(2); }); }); }); runs34
  35. 35. JASMINE - asynchronous - WAITS it('should be a test', function () { runs(function () { this.foo = 0; var that = this; setTimeout(function () { that.foo++; }, 250); }); runs(function () { expect(this.foo).toEqual(0); }); waits(1000); runs(function () { expect(this.foo).toEqual(1); }); }); waits35
  36. 36. 36 JASMINE - asynchronous - WAITS FOR describe('asynchronous wait for', function() { it('should wait for something', function () { var spreadsheet = new Spreadsheet(); waitsFor(function() { return true; // here you can call your function which should be true }, "Something went wrong", 3000); runs(function () { expect(2).toEqual(2); }); }); }); waitsFor(function, opt message, opt timeout)
  37. 37. JASMINE - jQuery matchers toBe(jQuerySelector) toBeChecked() toBeEmpty() toBeHidden() toHaveCss(css) toBeSelected() toBeVisible() toContain(jQuerySelector) toExist() toHaveAttr(attributeName, attributeValue) toHaveProp(propertyName, propertyValue) toHaveBeenTriggeredOn(selector) toHaveBeenTriggered() toHaveBeenTriggeredOnAndWith(selector, extraParameters) toHaveBeenPreventedOn(selector) toHaveBeenPrevented() toHaveClass(className) toHaveData(key, value) toHaveHtml(string) toContainHtml(string) toContainText(string) toHaveId(id) toHaveText(string) toHaveValue(value) toHaveLength(value) toBeDisabled() toBeFocused() toHandle(eventName) toHandleWith(eventName, eventHandler) 37
  38. 38. JASMINE - HTML & JSON fixtures //myfixture.html <div id="my-fixture">some complex content here</div> //some fixture adding loadFixtures('myfixture.html'); $('#my-fixture').myTestedPlugin(); expect($('#my-fixture')).toBe('div'); 38
  39. 39. JASMINE for AJAX 39 Sinon Jasmine AJAX
  40. 40. Github Present for WebStorm users 40 https://github.com/thisisui/jetbrains-jasmine-test-startup
  41. 41. 41 THANKS FOR YOUR TIME QUESTIONS?

×