BarCodeScanScreen tests

[PierreBresson]

Summary

Do different tests for BarCodeScreen inside BarCodeScreen.test.tsx matching the different scenario

[Kathuria]

Can I work on this issue?

[ijdershem]

Can I work on this issue?

@Kathuria Did you end up picking this issue up? @PierreBresson Happy to pick this up if not

[PierreBresson]

You can go for it, the comment is 21 days old and no pr has been done since then. I've pushed some changes so make sure to pull main first ;)

[ijdershem]

@PierreBresson Any chance you have experience testing useEffect/useState functionality? Not seeing any relevant tests in the code base and having a pretty difficult time figuring out how to trigger a component state update when user permission is granted for the camera.

This is the approach I'm taking right now:

it("renders correctly if permission is granted", async () => {
    // Mock useState before rendering your component
    const mockPermissionPromise:Promise<PermissionResponse> = new Promise((resolve) => ({
      status: PermissionStatus.GRANTED, 
      expires: "never", 
      granted: true, 
      canAskAgain: true,
    }));

    const permissionRequestSpy = jest.spyOn(BarCodeScanner, 'requestPermissionsAsync').mockReturnValue(mockPermissionPromise);
    let tree;
    await act( async () => {
      tree = create(<BarCodeScanScreen />);
    });
    expect(permissionRequestSpy).toHaveBeenCalled();
    expect(tree.toJSON()).toMatchSnapshot();
    permissionRequestSpy.mockRestore();
  });

However, the rendered tree still appears to be that of the hasPermission === null state:

exports['BarCodeScanScreen renders correctly if permission is granted 1'] = '
<View
  style={
    Object {
      "backgroundColor": "#FFFFFF",
      "flex": 1,
      "paddingHorizontal": 16,
    }
  }
/>
';

Will continue working for a solution but any help is appreciated! (:

[PierreBresson]

@ijdershem Unfortunately, I don't have a big experience with hooks testing, but you might have to mock expo-barcode-scanner by adding it to jest -> mock -> node_modules. Hope that helps :)

[ijdershem]

@PierreBresson No worries, thank you for the direction; I will give this a shot tonight!