javascript 如何使用 jasmine.js 测试控制台输出？
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How can I use jasmine.js to test for console output?
提问by Joe Susnick
I'm working through the text: Professional JavaScript for Web Developers by Nicholas Zakasand I'm testing the examples with Jasmine.js.
我正在阅读文本：Nicholas Zakas 所著的 Web 开发人员的专业 JavaScript，我正在使用 Jasmine.js 测试这些示例。
I can currently test the output of a function by specifying a return a value, but I'm running into trouble when there are multiple pieces of data that I want to return.
我目前可以通过指定返回值来测试函数的输出，但是当我想要返回多条数据时，我遇到了麻烦。
The textbook uses the alert() method, but this is cumbersome and I don't know how to test for alerts. I was wondering if there was a way to test for console.log() output. For instance:
教科书使用了alert()方法，但是这个很麻烦，不知道如何测试alert。我想知道是否有办法测试 console.log() 输出。例如：
function_to_test = function(){
var person = new Object();
person.name = "Nicholas";
person.age = 29;
return(person.name); //Nicholas
return(person.age); //29
});
I know I can have them return as one string, but for more complicated examples I'd like to be able to test the following:
我知道我可以让它们作为一个字符串返回，但是对于更复杂的示例，我希望能够测试以下内容：
function_to_test = function(){
var person = new Object();
person.name = "Nicholas";
person.age = 29;
console.log(person.name); //Nicholas
console.log(person.age); //29
});
The Jasmine test looks something like:
Jasmine 测试如下所示：
it("should test for the function_to_test's console output", function(){
expect(function_to_test()).toEqual("console_output_Im_testing_for");
});
Is there a simple way to do this that I'm just missing? I'm pretty new to coding so any guidance would be appreciated.
有没有一种简单的方法可以做到这一点，我只是想念？我对编码很陌生，所以任何指导都将不胜感激。
回答by Jason
There are a couple of things that are wrong with your code above. As pointed out, having multiple return statement will not work. Also, when defining a new object, it is preferable to use the object literal syntax over using new Object.
上面的代码有一些错误。正如所指出的，有多个 return 语句是行不通的。此外，在定义新对象时，最好使用对象字面量语法而不是使用new Object.
What you would normally do is something more like this:
你通常会做的是更像这样的事情：
var function_to_test = function () {
var person = {
name : "Nicholas",
age : 29
};
return person;
};
Using the function above, there are a couple of ways you could test this. One it to mock out the console.log object using Jasmine Spies.
使用上面的函数，有几种方法可以测试它。一种是使用Jasmine Spies模拟 console.log 对象。
it("should test for the function_to_test's console output", function () {
console.log = jasmine.createSpy("log");
var person = function_to_test();
expect(console.log).toHaveBeenCalledWith(person);
});
The other is to test the actual output of the function.
另一种是测试函数的实际输出。
it("should return a person", function () {
var person = function_to_test();
expect(person).toEqual({ name : "Nicholas", age : 29 });
});
