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Presentation about Jasmine - BDD
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JASMINEWhy JavaScript tests don’t smell fishy?
WHAT I WILL TALK ABOUT:
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• 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
WHY PEOPLE DON’T TEST JAVASCRIPT ?
• project not big enough
• project too complex
• asynchronous XHR requests
• DOM manipulation
• too many browsers, platforms, devices
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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
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GOOD PRACTICES
BENEFITS OF USING JAVASCRIPT TESTS
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• 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
TDD & BDD
Behavior Driven Development: agile software development technique testing from business value perspective, why some code is necessary and what its goal is
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Test Driven Development: write tests against specification, watch your test fail, write some code, test, refactor, test-fix-implement
TDD vs BDDExample: 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
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JASMINE MATCHERS - EQUALITYexpect(true).toEqual(true);expect({}).toEqual({});
8toEqual
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 Typesprimitive will be give you true, reference will give you false
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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
JASMINE MATCHERS - NEGATIONexpect(this).not.toEqual(that);expect({}).not.toBe([]);
not11
JASMINE MATCHERS - CONTAINSexpect([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
JASMINE MATCHERS - DEFINED OR UNDEFINED
var somethingUndefined;
expect("Hello!").toBeDefined(); // successexpect(null).toBeDefined(); // successexpect(somethingUndefined).toBeDefined(); // failure
var somethingElseUndefined;expect(somethingElseUndefined).toBeUndefined(); // successexpect(2013).toBeUndefined(); // failureexpect(null).toBeUndefined(); // failure
toBeDefined toBeUndefined13
JASMINE MATCHERS - NULLNESS
expect(null).toBeNull(); // successexpect(false).toBeNull(); // failureexpect(somethingUndefined).toBeNull(); // failure
//null is where the thing is known to exist, //but it's not known what the value is.
toBeNull14
JASMINE MATCHERS - IS NaN
expect(5).not.toBeNaN(); // success
expect(0 / 0).toBeNaN(); // successexpect(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
JASMINE MATCHERS - COMPARATORS
expect(8).toBeGreaterThan(5);
expect(5).toBeLessThan(12);expect("a").toBeLessThan("z"); // it works for strings
toBeGreaterThan toBeLessThan16
JASMINE MATCHERS - NEARNESS
expect(12.34).toBeCloseTo(12.3, 1); // success
toBeCloseTo17
JASMINE MATCHERS - REGULAR EXPRESSIONS
expect("some words").toMatch(/some/); // success
toMatch18
JASMINE MATCHERS - ERROR THROWING
var errorThrower = function () {
throw new Error();
}
expect(errorThrower).toThrow(); // success
toThrow19
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
JASMINE MATCHERS - CUSTOM MATCHERSbeforeEach( function () { this.addMatchers({ toBeLarge: function () { this.message = function () { return "Expected " + this.actual + " to be large"; }; return this.actual > 100; } });});
expect(5).toBeLarge(); // failureexpect(101).toBeLarge(); // success
custom matchers21
JASMINE - NESTED SUITSdescribe("Expected ", function () {
describe("something ", function () {
it("should do something", function () { expect(2).toBe(2); });
});
});
22describe describe
JASMINE - SKIP THE TESTdescribe("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); });
});
});
23xit xdescribe return
JASMINE - SPIESvar 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.
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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
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
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);});
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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"]);});
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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"]);});
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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
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
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JASMINE - SPIES can chain actions
person.getSecretAgentName = jasmine.createSpy("Name spy").andReturn("James Bond");
chaning
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
JASMINE - asynchronous - RUNS
it("runnin’", function() { runs(function() { it("should do something", function () { expect(2).toBe(2); }); });});
runs34
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
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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)
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)
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JASMINE - HTML & JSON fixtures
//myfixture.html<div id="my-fixture">some complex content here</div>
//some fixture addingloadFixtures('myfixture.html');$('#my-fixture').myTestedPlugin();expect($('#my-fixture')).toBe('div');
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JASMINE for AJAX
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Sinon
Jasmine AJAX
Github Present for WebStorm users
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https://github.com/thisisui/jetbrains-jasmine-test-startup
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THANKS FOR YOUR TIME
QUESTIONS?