Source for empty promise rejection?

[LinusU]

I think this got lost under the outdated diff, so reposting here just to be sure:

I was matching the browser API. Even if I reject with an error here, the user can't rely on that, since if the Async Clipboard API is used then it may reject without an error. I thought it was better to be consistent. Will add a comment.

Aha, interesting... I wonder why they would standardize around that 🤔

Do you have a link where I can read about this? I tried searching but to me, it didn't seem like the spec mentioned what the Promise should be rejected with.

In the chrome examples it seems like they reject with a proper error:

navigator.clipboard.writeText('Text to be copied')
  .then(() => {
    console.log('Text copied to clipboard');
  })
  .catch(err => {
    // This can happen if the user denies clipboard permissions:
    console.error('Could not copy text: ', err);
  });

ref: https://developers.google.com/web/updates/2018/03/clipboardapi#copy_writing_text_to_the_clipboard

ping @feross

[feross]

Yeah, I saw that in the Chrome example too, but it doesn't work in practice. There's no error returned.

The spec explainer omits error arguments:

  navigator.clipboard.writeText("some text").then(function() {
      // Promise resolved successfully.
      console.log("Copied to clipboard successfully!");
  }, function() {
      // Promise rejected.
      console.error("Unable to write to clipboard. :-(");
  });

And the spec itself doesn't say "reject promise P with error", but simply "reject promise P". So I'm led to believe there's no error argument.