[Expo] waitForElement: Promise constructor's argument is not a function

[wKovacs64]

Created a fresh Expo app and tried to use waitForElement, but it throws. Works fine in vanilla RN app.

Test:

it('renders', async () => {
  const { getByText } = render(<App />);

  await waitForElement(() => getByText(/working/));
});

Result:

TypeError: Promise constructor's argument is not a function

     7 |     const { getByText } = render(<App />);
     8 | 
  >  9 |     await waitForElement(() => getByText(/working/));
    10 |   });
    11 | });
    12 | 
    
    at new Promise (node_modules/promise/lib/core.js:59:11)
    at resolve (node_modules/react-native-testing-library/src/waitForElement.js:8:26)
    at Object.getByText (App.test.js:9:32)
    at tryCatch (node_modules/regenerator-runtime/runtime.js:62:40)
    at Generator.invoke [as _invoke] (node_modules/regenerator-runtime/runtime.js:296:22)
    at Generator.prototype.(anonymous function) [as next] (node_modules/regenerator-runtime/runtime.js:114:21)
    at tryCatch (node_modules/regenerator-runtime/runtime.js:62:40)
    at invoke (node_modules/regenerator-runtime/runtime.js:152:20)
    at node_modules/regenerator-runtime/runtime.js:195:11
    at tryCallTwo (node_modules/promise/lib/core.js:45:5)

I'm assuming it has something to do with Expo's jest-expo preset, but I haven't narrowed it down yet.

Reproduction repo if anyone wants to mess with it: https://github.com/wKovacs64/rntl-expo-test

[thymikee]

Based on stack trace looks like expo preset sets global promise to a npm promise module. Will have to investigate why it fails, but I have no access to my workstation this weekend

[wKovacs64]

Looks like react-native itself sets the global promise in its Jest setup script, and jest-expo includes that script in its setupFiles (as well as its own). But just glancing around react-native-testing-library, it doesn't seem like you're doing anything crazy that wouldn't work with the promise module (?).

[wKovacs64]

Fixed by #31, in case anyone stumbles upon this later.