| 提交 | 用户 | 时间 | ||
| 1ac2bc | 1 | |
| 懒 | 2 | describe('Function', function() { |
| 3 | "use strict"; | |
| 4 | describe('bind', function() { | |
| 5 | var actual, expected, | |
| 6 | testSubject; | |
| 7 | ||
| 8 | testSubject = { | |
| 9 | push: function(o) { | |
| 10 | this.a.push(o); | |
| 11 | } | |
| 12 | }; | |
| 13 | ||
| 14 | function func() { | |
| 15 | Array.prototype.forEach.call(arguments, function(a) { | |
| 16 | this.push(a); | |
| 17 | }, this); | |
| 18 | return this; | |
| 19 | }; | |
| 20 | ||
| 21 | beforeEach(function() { | |
| 22 | actual = []; | |
| 23 | testSubject.a = []; | |
| 24 | }); | |
| 25 | ||
| 26 | it('binds properly without a context', function() { | |
| 27 | var context; | |
| 28 | testSubject.func = function() { | |
| 29 | context = this; | |
| 30 | }.bind(); | |
| 31 | testSubject.func(); | |
| 32 | expect(context).toBe(function() {return this}.call()); | |
| 33 | }); | |
| 34 | it('binds properly without a context, and still supplies bound arguments', function() { | |
| 35 | var a, context; | |
| 36 | testSubject.func = function() { | |
| 37 | a = Array.prototype.slice.call(arguments); | |
| 38 | context = this; | |
| 39 | }.bind(undefined, 1,2,3); | |
| 40 | testSubject.func(1,2,3); | |
| 41 | expect(a).toEqual([1,2,3,1,2,3]); | |
| 42 | expect(context).toBe(function() {return this}.call()); | |
| 43 | }); | |
| 44 | it('binds a context properly', function() { | |
| 45 | testSubject.func = func.bind(actual); | |
| 46 | testSubject.func(1,2,3); | |
| 47 | expect(actual).toEqual([1,2,3]); | |
| 48 | expect(testSubject.a).toEqual([]); | |
| 49 | }); | |
| 50 | it('binds a context and supplies bound arguments', function() { | |
| 51 | testSubject.func = func.bind(actual, 1,2,3); | |
| 52 | testSubject.func(4,5,6); | |
| 53 | expect(actual).toEqual([1,2,3,4,5,6]); | |
| 54 | expect(testSubject.a).toEqual([]); | |
| 55 | }); | |
| 56 | ||
| 57 | it('returns properly without binding a context', function() { | |
| 58 | testSubject.func = function() { | |
| 59 | return this; | |
| 60 | }.bind(); | |
| 61 | var context = testSubject.func(); | |
| 62 | expect(context).toBe(function() {return this}.call()); | |
| 63 | }); | |
| 64 | it('returns properly without binding a context, and still supplies bound arguments', function() { | |
| 65 | var context; | |
| 66 | testSubject.func = function() { | |
| 67 | context = this; | |
| 68 | return Array.prototype.slice.call(arguments); | |
| 69 | }.bind(undefined, 1,2,3); | |
| 70 | actual = testSubject.func(1,2,3); | |
| 71 | expect(context).toBe(function() {return this}.call()); | |
| 72 | expect(actual).toEqual([1,2,3,1,2,3]); | |
| 73 | }); | |
| 74 | it('returns properly while binding a context properly', function() { | |
| 75 | var ret; | |
| 76 | testSubject.func = func.bind(actual); | |
| 77 | ret = testSubject.func(1,2,3); | |
| 78 | expect(ret).toBe(actual); | |
| 79 | expect(ret).not.toBe(testSubject); | |
| 80 | }); | |
| 81 | it('returns properly while binding a context and supplies bound arguments', function() { | |
| 82 | var ret; | |
| 83 | testSubject.func = func.bind(actual, 1,2,3); | |
| 84 | ret = testSubject.func(4,5,6); | |
| 85 | expect(ret).toBe(actual); | |
| 86 | expect(ret).not.toBe(testSubject); | |
| 87 | }); | |
| 88 | it('passes the correct arguments as a constructor', function() { | |
| 89 | var ret, expected = { name: "Correct" }; | |
| 90 | testSubject.func = function(arg) { | |
| 91 | return arg; | |
| 92 | }.bind({ name: "Incorrect" }); | |
| 93 | ret = new testSubject.func(expected); | |
| 94 | expect(ret).toBe(expected); | |
| 95 | }); | |
| 96 | it('returns the return value of the bound function when called as a constructor', function () { | |
| 97 | var oracle = [1, 2, 3]; | |
| 98 | var subject = function () { | |
| 99 | return oracle; | |
| 100 | }.bind(null); | |
| 101 | var result = new subject; | |
| 102 | expect(result).toBe(oracle); | |
| 103 | }); | |
| 104 | it('returns the correct value if constructor returns primitive', function() { | |
| 105 | var oracle = [1, 2, 3]; | |
| 106 | var subject = function () { | |
| 107 | return oracle; | |
| 108 | }.bind(null); | |
| 109 | var result = new subject; | |
| 110 | expect(result).toBe(oracle); | |
| 111 | ||
| 112 | oracle = {}; | |
| 113 | result = new subject; | |
| 114 | expect(result).toBe(oracle); | |
| 115 | ||
| 116 | oracle = function(){}; | |
| 117 | result = new subject; | |
| 118 | expect(result).toBe(oracle); | |
| 119 | ||
| 120 | oracle = "asdf"; | |
| 121 | result = new subject; | |
| 122 | expect(result).not.toBe(oracle); | |
| 123 | ||
| 124 | oracle = null; | |
| 125 | result = new subject; | |
| 126 | expect(result).not.toBe(oracle); | |
| 127 | ||
| 128 | oracle = true; | |
| 129 | result = new subject; | |
| 130 | expect(result).not.toBe(oracle); | |
| 131 | ||
| 132 | oracle = 1; | |
| 133 | result = new subject; | |
| 134 | expect(result).not.toBe(oracle); | |
| 135 | }); | |
| 136 | it('returns the value that instance of original "class" when called as a constructor', function() { | |
| 137 | var classA = function(x) { | |
| 138 | this.name = x || "A"; | |
| 139 | } | |
| 140 | var classB = classA.bind(null, "B"); | |
| 141 | ||
| 142 | var result = new classB; | |
| 143 | expect(result instanceof classA).toBe(true); | |
| 144 | expect(result instanceof classB).toBe(true); | |
| 145 | }); | |
| 146 | }); | |
| 147 | }); | |
