Question

我在react-scripts@2.1.8中将typescript@3.3.3与jest@.23.6.0结合使用并运行测试，但它们失败，并显示“未定义反应”。

 FAIL  src/components/Button/test.tsx
  ● <Button> › renders text correctly

    ReferenceError: React is not defined

       6 |     it('renders text correctly', () => {
       7 |         const text = 'hello there i am a test'
    >  8 |         const { getByText } = customRender(<Button>{text}</Button>)
         |                                            ^
       9 |         expect(getByText(/hello there i am a test/)).toBeTruthy()
      10 |     })
      11 |     it('matches the snapshot', () => {

      at Object.it (src/components/Button/test.tsx:8:44)

  ● <Button> › matches the snapshot

    ReferenceError: React is not defined

      10 |     })
      11 |     it('matches the snapshot', () => {
    > 12 |         const { container } = customRender(<Button />)
         |                                            ^
      13 |         expect(container.firstChild).toMatchSnapshot()
      14 |     })
      15 | })

      at Object.it (src/components/Button/test.tsx:12:44)

Button.test.tsx：

import React from 'react'
import Button from '.'
import { customRender } from '../../test-utils'

describe('<Button>', () => {
    it('renders text correctly', () => {
        const text = 'hello there i am a test'
        const { getByText } = customRender(<Button>{text}</Button>)
        expect(getByText(/hello there i am a test/)).toBeTruthy()
    })
    it('matches the snapshot', () => {
        const { container } = customRender(<Button />)
        expect(container.firstChild).toMatchSnapshot()
    })
})

还使用React import，就像将它从第1行移到第3行一样，有时似乎使测试通过。这很奇怪。

Answer 1

这是this issue中讨论和解释的jsx编译指示和情感10问题。

create-react-app测试“未定义反应”

1 个答案: