dragonfly环境搭建——单测 SpecRunner

作者：zccst

单测，在前端，对于我而言，还是第一次。得好好学学单测了。


看看介绍，慢慢来。

参考：
官方文档： http://jasmine.github.io/2.0/introduction.html
https://gist.github.com/OakRaven/2623232

断断续续看了两次，基本看懂了，下面是一些基础的用法，高级用法另写一篇吧

describe("Player", function() {
  var player;
  var song;

  beforeEach(function() {
    player = new Player();
    song = new Song();
  });

  it("should be able to play a Song", function() {
    player.play(song);
    expect(player.currentlyPlayingSong).toEqual(song);

    //demonstrates use of custom matcher
    expect(player).toBePlaying(song);
  });

  describe("when song has been paused", function() {
    beforeEach(function() {
      player.play(song);
      player.pause();
    });

    it("should indicate that the song is currently paused", function() {
      expect(player.isPlaying).toBeFalsy();

      // demonstrates use of 'not' with a custom matcher
      expect(player).not.toBePlaying(song);
    });

    it("should be possible to resume", function() {
      player.resume();
      expect(player.isPlaying).toBeTruthy();
      expect(player.currentlyPlayingSong).toEqual(song);
    });
  });

  // demonstrates use of spies to intercept and test method calls
  it("tells the current song if the user has made it a favorite", function() {
    spyOn(song, 'persistFavoriteStatus');

    player.play(song);
    player.makeFavorite();

    expect(song.persistFavoriteStatus).toHaveBeenCalledWith(true);
  });

  //demonstrates use of expected exceptions
  describe("#resume", function() {
    it("should throw an exception if song is already playing", function() {
      player.play(song);

      expect(function() {
        player.resume();
      }).toThrowError("song is already playing");
    });
  });


  /**/
  describe("The 'toEqual' matcher", function() {
	//测toBe
	it("The 'toBe' matcher compares with ===", function() {
		var a = 12;
		var b = a;
		expect(a).toBe(b);
		expect(a).not.toBe(null);
	});

	//测toEqual
    it("works for simple literals and variables", function() {
      var a = 12;
      expect(a).toEqual(12);
    });
    it("should work for objects", function() {
      var foo = {
        a: 12,
        b: 34
      };
      var bar = {
        a: 12,
        b: 34
      };
      expect(foo).toEqual(bar);
    });


	  //测toMatch
	  it("The 'toMatch' matcher is for regular expressions", function() {
		var message = "foo bar baz";
		expect(message).toMatch(/bar/);
		expect(message).toMatch("bar");
		expect(message).not.toMatch(/quux/);
	  });

	  //测toBeDefined
	  it("The 'toBeDefined' matcher compares against `undefined`", function() {
		var a = {
		  foo: "foo"
		};
		expect(a.foo).toBeDefined();
		expect(a.bar).not.toBeDefined();
	  });
	  //测`toBeUndefined`
	  it("The `toBeUndefined` matcher compares against `undefined`", function() {
		var a = {
		  foo: "foo"
		};
		expect(a.foo).not.toBeUndefined();
		expect(a.bar).toBeUndefined();
	  });
	  //测toBeNull
	  it("The 'toBeNull' matcher compares against null", function() {
		var a = null;
		var foo = "foo";
		expect(null).toBeNull();
		expect(a).toBeNull();
		expect(foo).not.toBeNull();
	  });
	  //测toBeTruthy
	  it("The 'toBeTruthy' matcher is for boolean casting testing", function() {
		var a, foo = "foo";
		expect(foo).toBeTruthy();
		expect(a).not.toBeTruthy();
	  });
	  //测toBeFalsy
	  it("The 'toBeFalsy' matcher is for boolean casting testing", function() {
		var a, foo = "foo";
		expect(a).toBeFalsy();
		expect(foo).not.toBeFalsy();
	  });
	  //测toContain（针对数组）
	  it("The 'toContain' matcher is for finding an item in an Array", function() {
		var a = ["foo", "bar", "baz"];
		expect(a).toContain("bar");
		expect(a).not.toContain("quux");
	  });
	  //测toBeLessThan
	  it("The 'toBeLessThan' matcher is for mathematical comparisons", function() {
		var pi = 3.1415926,
		  e = 2.78;
		expect(e).toBeLessThan(pi);
		expect(pi).not.toBeLessThan(e);
	  });
	  //测toBeGreaterThan
	  it("The 'toBeGreaterThan' matcher is for mathematical comparisons", function() {
		var pi = 3.1415926,
		  e = 2.78;
		expect(pi).toBeGreaterThan(e);
		expect(e).not.toBeGreaterThan(pi);
	  });
	  //测toBeCloseTo，第二个参数比较费解，看源码后知道是10的x次方，然后四舍五入
	  it("The 'toBeCloseTo' matcher is for precision math comparison", function() {
		var pi = 3.1415926,
		  e = 2.78;
		expect(pi).not.toBeCloseTo(e, 2);//乘以10的2次方，扩大100倍，然后四舍五入
		expect(pi).toBeCloseTo(e, 0);//乘以10的0次方，扩大1倍，然后四舍五入
	  });
	  //测toThrow
	  it("The 'toThrow' matcher is for testing if a function throws an exception", function() {
		var foo = function() {
		  return 1 + 2;
		};
		var bar = function() {
		  return a + 1;
		};
		expect(foo).not.toThrow();
		expect(bar).toThrow();
	  });


  });


  //The this keyword
  describe("A spec", function() {
	  var bar1;
	  //beforeEach，afterEach里可以设置this.xx变量，而且在全部it里有效
	  beforeEach(function() {
		this.foo = 0;
		bar1 = "hello";//有效
	  });

	  //但是一个it里的this.xx变量，在另一个it里无效
	  it("can use the `this` to share state", function() {
		expect(this.foo).toEqual(0);
		this.bar = "test pollution?";
		//bar1 = "hello";//无效
	  });

	  it("prevents test pollution by having an empty `this` created for the next spec", function() {
		expect(this.foo).toEqual(0);
		expect(this.bar).toBe(undefined);//true，未被另一个it污染
		expect(bar1).toBe("hello");
	  });
	});




	//嵌套
	describe("A spec", function() {
	  var foo;

	  beforeEach(function() {
		foo = 0;
		foo += 1;
	  });

	  afterEach(function() {
		foo = 0;
	  });

	  it("is just a function, so it can contain any code", function() {
		expect(foo).toEqual(1);
	  });

	  it("can have more than one expectation", function() {
		expect(foo).toEqual(1);
		expect(true).toEqual(true);
	  });

	  //先执行内部describe，再执行外部的afterEach
	  //外部的变量，可以在内部describe访问
	  describe("nested inside a second describe", function() {
		var bar;

		beforeEach(function() {
		  bar = 1;
		});

		it("can reference both scopes as needed", function() {
		  expect(foo).toEqual(bar);
		});
	  });
	});

	//对于describe，直接改成xdescribe即可
	//悬而未决，挂起  运行后，点击显示是*号。
	describe("Pending specs", function() {
	
	    xit("can be declared 'xit'",function(){
			expect(true).toBe(false);
		});
		it("can be declared with 'it' but without a function");
		it("can be declared by calling 'pending' in the spec body", function() {
			expect(true).toBe(false);
			pending();
		  });
	});






});