Manipulating ClipboardEvent.clipboardData

[ph-fritsche]

• @testing-library/user-event version: v14.0.0-beta.11

Relevant code or config

document.addEventListener('copy', e => e.clipboardData.setData('text', 'bar'))

document.addEventListener('cut', e => e.clipboardData.setData('text', 'bar'))

document.addEventListener('paste', e => e.clipboardData.setData('text', 'bar'))

Problem description:

When double-checking #862 and #866 , I discovered that accessing/manipulating ClipboardEvent.clipboardData is limited.

(In Firefox:)

The data written to Clipboard is independent from the clipboardData on the cut/copy event. Manipulating has no effect.
Also the handler cannot read the clipboard data.

The data pasted from Clipboard is readable on the paste event. But manipulating it results in a DOMException.

Suggested solution:

Check consistency across browsers. If it is, implement API accordingly.

[SalahAdDin]

It would be nice to have a wait to mock the api, right now the permission checking does not work on it (i.e., navigator.permissions.query({name: "clipboard-read"})).