README.md

jest-mocking-esm

trying to get the examples published by Jest to actually work for ESM

Jest Issues is filled with issues involving ESM

Jest Docs say they can mock ES6 classes and have a Complete Example which is what I copied here and tried to get working

The Mocking Modules Docs once again make it seem like mocking things like Axios work "out of the box"....

Other Jest Docs seem to indicate it just doesn't work:

Please note that we currently don't support jest.mock in a clean way in ESM, but that is something we intend to add proper support for in the future. Follow this issue for updates.

I can't get the provide example to work!! What am I doing wrong????

Usage

1. clone the repo
2. cd into the rep
3. run npm run test

Results

➜  repos/poc/jest-testing (main) ✗ > npm run test

> [email protected] test
> NODE_OPTIONS=--experimental-vm-modules npx jest

(node:6018) ExperimentalWarning: VM Modules is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
 FAIL  src/sound-player-consumer.test.js
  ✕ The consumer should be able to call new() on SoundPlayer (1 ms)
  ✕ We can check if the consumer called the class constructor
  ✕ We can check if the consumer called a method on the class instance (1 ms)

  ● The consumer should be able to call new() on SoundPlayer

    TypeError: SoundPlayer.mockClear is not a function

      11 |
      12 | beforeEach(() => {
    > 13 |   SoundPlayer.mockClear();
         |               ^
      14 |   mockPlaySoundFile.mockClear();
      15 | });
      16 |

      at Object.<anonymous> (src/sound-player-consumer.test.js:13:15)

  ● We can check if the consumer called the class constructor

    TypeError: SoundPlayer.mockClear is not a function

      11 |
      12 | beforeEach(() => {
    > 13 |   SoundPlayer.mockClear();
         |               ^
      14 |   mockPlaySoundFile.mockClear();
      15 | });
      16 |

      at Object.<anonymous> (src/sound-player-consumer.test.js:13:15)

  ● We can check if the consumer called a method on the class instance

    TypeError: SoundPlayer.mockClear is not a function

      11 |
      12 | beforeEach(() => {
    > 13 |   SoundPlayer.mockClear();
         |               ^
      14 |   mockPlaySoundFile.mockClear();
      15 | });
      16 |

      at Object.<anonymous> (src/sound-player-consumer.test.js:13:15)

Test Suites: 1 failed, 1 total
Tests:       3 failed, 3 total
Snapshots:   0 total
Time:        0.444 s, estimated 1 s