柴:无法读取未定义的属性“不" [英] chai: Cannot read property 'not' of undefined

问题描述

我是chai和mocha的新手，我在第一个测试用例中使用了示例代码.这是我的代码.

I am new to chai and mocha and I use the sample code for my first test case. Here is my code.

var chai = require("chai");
var mocha = require("mocha");
var expect = chai.expect;

describe("Test", function() {
    it("Test", function() {
        expect([1, 2]).to.be.an('array').that.does.not.include(3);
    });
});

我运行mocha test.js

结果是:

TypeError: Cannot read property 'not' of undefined

我怎么了?看来.does返回未定义.我删除了.does，它可以正常工作.正确的用法是什么?

What is wrong with me? It seems .does return undefined. I remove .does and it works correctly. What is the correct usage?

以下代码有效.

expect([1, 2]).to.be.an('array').that.not.include(3);

推荐答案

如果我使用Chai 4运行您的代码，它就可以工作.当我将其降级为Chai 3时，您会收到错误消息. Chai 4.0.0中将does添加为无操作断言.您使用的Chai版本早于4.0.0.

If I run your code with Chai 4, it works. When I downgrade it to Chai 3 I get the error you get. does was added as a no-op assertion in Chai 4.0.0. You are using a version of Chai that predates 4.0.0.

如果您查看发布信息，则会发现版本4.0.0如下:

If you check the releases information, you'll find for version 4.0.0, this:

添加does和but作为新的无操作声明. (相关问题:#700，#339 PR:#621，#701)

Add does and but as new no-op assertion. (Related Issues: #700, #339 PRs: #621, #701)

(您可以在Github中找到相同的信息发行版 ，还有一个好处，就是问题编号是指向实际问题的链接.)

(You can find the same information in the Github release, with the added benefit that the issue numbers are links to the actual issues.)

这篇关于柴:无法读取未定义的属性“不"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！