为什么我无法从jasmine中的javascript函数访问全局变量 [英] Why I can't access global variable from javascript function in jasmine

问题描述

我正在使用Jasmine独立版 https://github.com/jasmine/jasmine/releases

I'm using Jasmine standalone https://github.com/jasmine/jasmine/releases

我在 SpecRunner.html 中声明了一个全局变量global_song（我可以从chrome控制台访问它，所以它是真正全球化的，其中包括我试图将global_song连接到应该能够播放歌曲的脚本：

I have declared a global variable global_song in SpecRunner.html (I can access it from chrome console so it's truly global) which includes script where I am trying to concatenate global_song to "should be able to play Song " :

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

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

为什么它无法访问 global_song 变量？

Why it cannot access global_song variable ?

更新： expect（player.currentlyPlayingSong）.toEqual（global_song）有效，而 it（应该能够播放歌曲+ global_song 不起作用。

Update : expect(player.currentlyPlayingSong).toEqual(global_song) works whereas it("should be able to play Song " + global_song doesn't work.

推荐答案

嗯，我认为你的 global_song 是在执行

Well i suppose your global_song created after executing of

player.play(song);

这种方式在测试中不可用作<$ c的第一个参数$ c> it 并在 expect（player.currentlyPlayingSong）.toEqual（global_song）<执行 player.play 后可用/ code>断言。

That's way it's not available in test as first parameter of it and available after executing player.play in expect(player.currentlyPlayingSong).toEqual(global_song) assertion.

尝试将简单赋值添加到 global_song 与 player.play 在执行 player.play 之前验证它是否可用：

Try to add simple assignment to global_song separatelly from player.play to verify that it's available before player.play executed:

window.global_song = 'value'

只需查看该示例，以说明问题的主要候选人：

Just take a look on that sample to illustrate the main possible candidate of problem:

function foo(){
    window['bar'] = 'bar';
}

console.log(window.bar); // Undefined
foo(); // now window contain bar variable.
console.log(window.bar); // 'bar'

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