预期[]为[] Jasmine，如何检查空数组 [英] Expected [ ] to be [ ] Jasmine, how to check empty array

问题描述

尝试检查空数组时出错。我尝试使用：

Getting error while trying to check for empty array. I tried using:

案例1：初始化为数组

expect(fixture.componentInstance.dataSource).toBe([]);

案例2：初始化为数组

let expectedAry = new Array;
expect(fixture.componentInstance.dataSource).toBe(expectedAry);

两种情况都有相同的错误：

Both the case have the same error:

Expected [  ] to be [  ].

阵列也可以通过长度检查，以下工作正常

Arrays can also be checked by their length, the following works fine

expect(fixture.componentInstance.dataSource.length).toEqual(0); 

0长度是一个选项，但不确定这是否是检查阵列是否正确的正确方法空。我们有更好的选择来检查数组是否为空吗？

0 length is an option, but not sure if that is the right way to check whether an array is empty. Do we have a better option for checking whether an array is empty?

推荐答案

toBe 是一个明确的参考检查。

toBe is an explicit reference check.

expect（[1]）。toBe（[1]）将失败，因为引用不同。

expect([1]).toBe([1]) will fail because the references are different.

你应该使用 toEqual ，它有一些智能来检查数组内容而不是仅仅进行参考比较。

You should use toEqual, which has some smarts to check the array contents as opposed to just doing a reference comparison.

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