抛出新错误是我的语法错误吗？我的测试失败了......不知道为什么答案

【问题标题】：is my syntax wrong with throwing new error? My test is failing... not sure why抛出新错误是我的语法错误吗？我的测试失败了......不知道为什么
【发布时间】：2021-01-22 07:13:48
【问题描述】：

我是 Javascript 新手，目前正在学习课程和测试。我的测试在测试错误时失败。我的类代码、测试代码和测试结果如下。

如果我遗漏了一些明显的东西，我很抱歉，我很新并且已经被扔进去了。

类：

class Bag {
    constructor(weight) {
        if (!weight) throw new Error("bag must have a weight")
        this.weight = weight
    }
}


module.exports = Bag

测试代码：

const { TestScheduler } = require("jest")

const Bag = require("./bag")

describe("bag", () => {
    test("has a weight", () => {
        const bag = new Bag(13)
        expect(bag.weight).toBe(13)
    })
    test("bag must have a weight", () => {
        const bag = new Bag()
        expect(() => new Bag()).toThrowError("bag must have a weight")
    })
})

测试结果：

Debugger attached.
 FAIL  ./airport.test.js
  bag
    ✓ has a weight (1 ms)
    ✕ bag must have a weight (1 ms)

  ● bag › bag must have a weight

    bag must have a weight

      2 |     constructor(weight) {
      3 |         if (!weight) {
    > 4 |             throw new Error("bag must have a weight")
        |                   ^
      5 |         }
      6 |         this.weight = weight
      7 |     }

      at new Bag (bag.js:4:19)
      at Object.<anonymous> (airport.test.js:11:21)

  console.log
    16

      at Object.<anonymous> (bag.js:11:9)

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 passed, 2 total
Snapshots:   0 total
Time:        1.166 s
Ran all test suites.
Waiting for the debugger to disconnect...
npm ERR! Test failed.  See above for more details.

【问题讨论】：

标签： javascript class jestjs tdd throw

【解决方案1】：

在您的第二次测试中，您在期望语句之前得到和错误：

test("bag must have a weight", () => {
        const bag = new Bag() // here!
        expect(() => new Bag()).toThrowError("bag must have a weight")
    })

只要去掉这一行，测试就可以了。

【讨论】：