为什么我的 Vue 单元测试无法识别函数？

Question

I'm currently writing simple unit tests (using Jest) for my component dateFormat.js that contains the function formatDateGlobal. Here's a snippet of the test:

import DateFormat from '../dateFormat';

describe('dateFormat.js', () => {
  let date1;

  beforeEach(() => {
    date1 = {
      date: '',
    };
  });

  it('Then it should return an empty string', () => {
    // Act
    const returnedDate = DateFormat.formatDateGlobal(date1);
    // Assert
    expect(returnedDate).toBe('');
  });

At the bottom of dateFormat, I'm exporting the formatDateGlobal function as so:

export default formatDateGlobal;

The tests are built as expected, but I'm getting the error

TypeError: _dateFormat.default.formatDateGlobal is not a function

      27 |   it('Then it should return an empty string', () => {
      28 |     // Act
    > 29 |     const returnedDate = DateFormat.formatDateGlobal(date1);
         |                                     ^
      30 |     // Assert
      31 |     expect(returnedDate).toBe('');
      32 |   });

Not really sure why this is happening, but I'm thinking it has to do with the way I'm exporting the function.

Answer 1

You are importing formatDateGlobal into DateFormat variable. So you can use const returnedDate = DateFormat(date1);

currently you're trying to achieve equivalent of this: const returnedDate = formatDateGlobal.formatDateGlobal(date1);