Wrapper existence check doesn't work correctly

[horaklukas]

Using wrapperId to distinguish wrapper elements of more receivers doesn't work because of check for wrapper element existence in constructor.

Consider test below, it should pass, but it fails with "wrapper element with Id customId not found" error. Same happens when using it in real browser.

it('should not throw if wrapperId is given and element elements having that id exists', () => {
    expect(() => mount(
        <div id="customId">
          <Receiver
            wrapperId="customId"
            onDragEnter={emptyFn}
            onDragOver={emptyFn}
            onDragLeave={emptyFn}
            onFileDrop={emptyFn}
          />
        </div>
    )).not.toThrow();
});

It's probably caused by timing check, in component constructor is too early because whole elements tree haven't fully rendered yet.

[lionng429]

@horaklukas Thanks so reporting the issue and this is a very good catch! I created a PR #18 to fix this issue.

FYI, the test case you mentioned above will always fail, not because of the placement of existence check, but the nature of mount() that it does not attach the component to the document, and this is the reference. I stuck a bit when adding the unit test, and I hope it would help in case you had the same problem.

Thanks once again for you time on checking the changes!

[horaklukas]

Looks good, thanks for quick fix. Also big thanks for sharing the trick about mounting to the document, I did't know that before! 👍

[horaklukas]

I will test it tomorrow and then close the issue 😉

[lionng429]

all good :) I tested a bit with the basic example and it should work. 0.4.1 is published as well. thanks once again for checking.