[Problem/Bug]: Clipboard write API doesn't support multiple mime types

[chriche-ms]

What happened?

Writing to the clipboard with multiple mime types does not work, only the last type is written to the clipboard.

Importance

Important. My app's user experience is significantly compromised.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

128.0.2739.67

SDK Version

1.0.2592.51

Framework

Win32

Operating System

Windows 11

OS Version

22631.4037

Repro steps

function getClipboardBlob(text, type) {
  return new Blob([text], { type });
}

function getClipboardItems(text, html) {
  const typeText = "text/plain";
  const blobText = getClipboardBlob(text, typeText);

  const typeHtml = "text/html";
  const blobHtml = getClipboardBlob(html, typeHtml);

  const items = [
    new ClipboardItem({ [typeText]: blobText, [typeHtml]: blobHtml }),
  ];

  return items;
}

async function writeClipboardTextAsync(text) {
  try {
    const html = `<a href="${text}">Link!</a>`;

    await navigator.clipboard.write(getClipboardItems(text, html));
  } catch (error) {
    console.error(error.message);
  }
}

Using this code to write multiple mime types to the clipboard does not work as expected. Only one of the types is added to the clipboard (the expected behaviour is for both types to be added to the clipboard with applications that understand html content pasting the anchor element while other apps receive the plain text). Reading the clipboard contents directly after the write call shows only a single type returned from ClipboardItem.getTypes (the 'last' property in the object passed to the ClipboardItem constructor).

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Don't know

Last working version (if regression)

No response

AB#54073971

[victorhuangwq]

No longer repro in 129.0.2792.52