TypeError：无法读取未定义+ Jest + NodeJS的属性“ prototype”

Question

我在NodeJS API中使用Jest进行单元测试。我已经安装了jest并将其添加到package.json中的脚本中。但是面对这个问题：

FAIL api / test / math.test.js ●测试套件无法运行

TypeError: Cannot read property 'prototype' of undefined

 at module.exports (node_modules/request-promise-core/configure/request2.js:34:48)
 at Object.<anonymous> (node_modules/request-promise-native/lib/rp.js:15:1)
 at Object.<anonymous> (node_modules/jsdom/lib/api.js:6:17)

 Test Suites: 1 failed, 1 total
 Tests:       0 total
 Snapshots:   0 total
 Time:        0.091s
 Ran all test suites.
 npm ERR! code ELIFECYCLE
 npm ERR! errno 1
 npm ERR! chain-analytics@1.0.0 test: `jest`
 npm ERR! Exit status 1
 npm ERR!
 npm ERR! Failed at the sample-project@1.0.0 test script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

下面是我的示例类：

math.js：

  const sum = (a, b) => a + b
  const mul = (a, b) => a * b
  const sub = (a, b) => a - b
  const div = (a, b) => a / b

  export default { sum, mul, sub, div };

math.test.js：

 const  {sum, mul, sub, div}  = require("./math")

 test("Adding 1 + 1 equals 2", () => {
   expect(sum(1, 1)).toBe(2)
 })
 test("Multiplying 1 * 1 equals 1", () => {
   expect(mul(1, 1)).toBe(1)
 })
 test("Subtracting 1 - 1 equals 0", () => {
   expect(sub(1, 1)).toBe(0)
 })
 test("Dividing 1 / 1 equals 1", () => {
   expect(div(1, 1)).toBe(1)
 })

任何建议都值得赞赏。谢谢！

Answer 1

将math.js中的出口更改为：

module.exports = { sum, mul, sub, div };

我相信NodeJS不支持ES6导入/导出语法。

Answer 2

导出使用导入。 module.exports会给您require。

模块和要求

您应该更改math.js：

module.exports = { sum, mul, sub, div };

对于代码：

const {sum, mul, sub, div} = require("./math");

导入/导出

或者您应该使用：

import { sum, mul, sub, div } from "./math";

对于代码：

export default { sum, mul, sub, div };

这是正确的组合。

Answer 3

q.js：

function sum(a, b) {
  return a + b;
}

module.exports = sum;

q.test.js：

const sum = require('../src/q');

test('adds 1 + 2 to equal 3', () => {
  const result = sum(1, 3);
  expect(result).toBe(3);
});

即使给出错误，也完全从jest文档中复制了此错误！ https://jestjs.io/docs/en/getting-started