1、Jasmine 之 Spies
代码示例:
describe("A spy", function() { var foo, bar = null; beforeEach(function() { foo = { setBar: function(value) { bar = value; } }; spyOn(foo, 'setBar'); foo.setBar(123); foo.setBar(456, 'another param'); }); it("tracks that the spy was called", function() { expect(foo.setBar).toHaveBeenCalled(); }); it("tracks that the spy was called x times", function() { expect(foo.setBar).toHaveBeenCalledTimes(2); }); it("tracks all the arguments of its calls", function() { expect(foo.setBar).toHaveBeenCalledWith(123); expect(foo.setBar).toHaveBeenCalledWith(456, 'another param'); }); it("stops all execution on a function", function() { expect(bar).toBeNull(); }); it("tracks if it was called at all", function() { foo.setBar(); expect(foo.setBar.calls.any()).toEqual(true); }); });
示例代码讲解:
Jasmine 有双重功能,即间谍 (spies) (spy)
spy可以存根任何函数,并跟踪调用他的所有参数。
spy只存在于定义他的 describe 或 it 块中,并且在每个 it (spec 规范)之后将被删除。
spy有自己特定的匹配器,用来断言(expect)。
断言匹配器:
toHaveBeenCalled:判断spy是否被调用过,被调用过即断言通过。
toHaveBeenCalledTimes(次数):方法参数为数字,即断言当前spy是否被调用过几次
toHaveBeenCalledWith():方法接收一个参数,即断言当前spy是否使用用当前参数调用过
calls():追踪spy被调用过的所有的参数
2、createSpy
代码示例:
describe("A spy, when created manually", function() { var whatAmI; beforeEach(function() { whatAmI = jasmine.createSpy('whatAmI'); whatAmI("I", "am", "a", "spy"); }); it("tracks that the spy was called", function() { expect(whatAmI).toHaveBeenCalled(); }); });
示例代码讲解:
当没有可以spyon的功能对象或者方法时,可以通过 jasmine.createSpy() 创建一个空的spy。
这个spy可以充当任何其他spy被调用,追踪。但是他没有实例。
3、createSpyObj
代码示例:
describe("Multiple spies, when created manually", function() { var tape; beforeEach(function() { tape = jasmine.createSpyObj('tape', ['play', 'pause', 'stop', 'rewind']); tape.play(); tape.pause(); tape.rewind(0); }); it("creates spies for each requested function", function() { expect(tape.play).toBeDefined(); expect(tape.pause).toBeDefined(); expect(tape.stop).toBeDefined(); expect(tape.rewind).toBeDefined(); }); });
示例代码讲解:
使用 jasmine.createSpyObj() 有序的创建一个具有多个spy的mock(模拟),
jasmine.createSpyObj('名称', ['spy1', 'spy2'])
参数:
参数一:名称
参数二:字符串数组
返回一个对象,参数数组中的每一项即为对象的属性,也是spy。
4、一些巧妙的匹配器
4.1 jasmine.any()
代码示例:
describe("jasmine.any", function() { it("matches any value", function() { expect({}).toEqual(jasmine.any(Object)); expect(12).toEqual(jasmine.any(Number)); }); describe("when used with a spy", function() { it("is useful for comparing arguments", function() { var foo = jasmine.createSpy('foo'); foo(12, function() { return true; }); expect(foo).toHaveBeenCalledWith(jasmine.any(Number), jasmine.any(Function)); }); }); });
示例代码讲解:
jasmine.any():方法接收数据类型作为参数,断言实际值是否是期望数据类型
4.2 jasmine.anything()
代码示例:
describe("jasmine.anything", function() { it("matches anything", function() { expect(1).toEqual(jasmine.anything()); }); describe("when used with a spy", function() { it("is useful when the argument can be ignored", function() { var foo = jasmine.createSpy('foo'); foo(12, function() { return false; }); expect(foo).toHaveBeenCalledWith(12, jasmine.anything()); }); }); });
示例代码讲解:
jasmine.anything():断言实际值是否不是null或者未定义,如果不是null或者未定义,即返回 true
4.3 jasmine.objectContaining
代码示例:
describe("jasmine.objectContaining", function() { var foo; beforeEach(function() { foo = { a: 1, b: 2, bar: "baz" }; }); it("matches objects with the expect key/value pairs", function() { expect(foo).toEqual(jasmine.objectContaining({ bar: "baz" })); expect(foo).not.toEqual(jasmine.objectContaining({ c: 37 })); }); describe("when used with a spy", function() { it("is useful for comparing arguments", function() { var callback = jasmine.createSpy('callback'); callback({ bar: "baz" }); expect(callback).toHaveBeenCalledWith(jasmine.objectContaining({ bar: "baz" })); }); }); });
示例代码讲解:
jasmine.objectContaining():接收一个对象参数,用于断言实际值为对象的,且对象是否包含参数对象中的键值对
4.4 jasmine.arrayContaining
代码示例:
describe("jasmine.arrayContaining", function() { var foo; beforeEach(function() { foo = [1, 2, 3, 4]; }); it("matches arrays with some of the values", function() { expect(foo).toEqual(jasmine.arrayContaining([3, 1])); expect(foo).not.toEqual(jasmine.arrayContaining([6])); }); describe("when used with a spy", function() { it("is useful when comparing arguments", function() { var callback = jasmine.createSpy('callback'); callback([1, 2, 3, 4]); expect(callback).toHaveBeenCalledWith(jasmine.arrayContaining([4, 2, 3])); expect(callback).not.toHaveBeenCalledWith(jasmine.arrayContaining([5, 2])); }); }); });
示例代码讲解:
jasmine.arrayContaining():接收一个数组参数,用于断言实际值为数组,且数组是否包含参数数组中的项
4.5 jasmine.stringMatching
代码示例:
describe('jasmine.stringMatching', function() { it("matches as a regexp", function() { expect({foo: 'bar'}).toEqual({foo: jasmine.stringMatching(/^bar$/)}); expect({foo: 'foobarbaz'}).toEqual({foo: jasmine.stringMatching('bar')}); }); describe("when used with a spy", function() { it("is useful for comparing arguments", function() { var callback = jasmine.createSpy('callback'); callback('foobarbaz'); expect(callback).toHaveBeenCalledWith(jasmine.stringMatching('bar')); expect(callback).not.toHaveBeenCalledWith(jasmine.stringMatching(/^bar$/)); }); }); });
示例代码讲解:
jasmine.stringMatching():接收字符串或者正则表达式为参数,
用于不希望精确地匹配较大对象中的字符串时,或者匹配spy中的一部分字符串(此处说法较为复杂难解,直接参考代码即可理解)
4.6 自定义检测器
代码示例:
describe("custom asymmetry", function() { var tester = { asymmetricMatch: function(actual) { var secondValue = actual.split(',')[1]; return secondValue === 'bar'; } }; it("dives in deep", function() { expect("foo,bar,baz,quux").toEqual(tester); }); describe("when used with a spy", function() { it("is useful for comparing arguments", function() { var callback = jasmine.createSpy('callback'); callback('foo,bar,baz'); expect(callback).toHaveBeenCalledWith(tester); }); }); }); });
示例代码讲解:
当我们需要断言某变量是否符合特定条件时,可以通过自定义一个具有 asymmetricMatch 函数作为其属性的对象,来指定一个定制的测试器。
5、jasmine Clock
代码示例:
describe("Manually ticking the Jasmine Clock", function() { var timerCallback; beforeEach(function() { timerCallback = jasmine.createSpy("timerCallback"); jasmine.clock().install(); }); afterEach(function() { jasmine.clock().uninstall(); }); it("模拟js的超时函数", function() { setTimeout(function() { timerCallback(); }, 100); expect(timerCallback).not.toHaveBeenCalled(); jasmine.clock().tick(101); expect(timerCallback).toHaveBeenCalled(); }); it("causes an interval to be called synchronously", function() { setInterval(function() { timerCallback(); }, 100); expect(timerCallback).not.toHaveBeenCalled(); jasmine.clock().tick(101); expect(timerCallback.calls.count()).toEqual(1); jasmine.clock().tick(50); expect(timerCallback.calls.count()).toEqual(1); jasmine.clock().tick(50); expect(timerCallback.calls.count()).toEqual(2); }); describe("Mocking the Date object", function() { it("mocks the Date object and sets it to a given time", function() { var baseTime = new Date(2013, 9, 23); jasmine.clock().mockDate(baseTime); jasmine.clock().tick(50); expect(new Date().getTime()).toEqual(baseTime.getTime() + 50); }); }); });
示例代码讲解:
Jasmine Clock 用于测试与时间相关的代码。
jasmine.clock().install():在需要操作时间的 describe 或者 it 中,安装时间控件才能进行时间相关操作
jasmine.clock().uninstall():在不需要操作时间后,一定要卸载时间控件。
jasmine.clock().tick():接收毫秒为单位的时间,实现时间后推移
jasmine.clock().mockDate():接收时间参数(时间戳),如果不传参数,默认为当前时间,用来模拟当前时间