Argument of type { [x: string]: Blob; } is not assignable to parameter of type Record<string, ClipboardItemData>

[Bahman-66]

lib Update Request

Configuration Check

My compilation target is ES2017 and my lib is ES2018.

Missing / Incorrect Definition

error TS2345: Argument of type '{ [x: string]: Blob; }' is not assignable to parameter of type 'Record<string, ClipboardItemData>'.
  'string' index signatures are incompatible.
    Type 'Blob' is missing the following properties from type 'Promise<ClipboardItemDataType>': then, catch, finally, [Symbol.toStringTag]

Sample Code

graphicDiv.addEventListener(
  'dragend',
  (event) => {
    const canvas = <HTMLCanvasElement>document.getElementById('canvas');
    canvas.toBlob((blob) => {
      if (blob) {
        let data = [new ClipboardItem({ [blob.type]: blob })];

        navigator.clipboard.write(data).then(
          function () {},
          function (err) {}
        );
      }
    });
  },
  false
);   

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/API/Navigator/clipboard

[IllusionMH]

This matches definition of ClipboardItemData in https://www.w3.org/TR/clipboard-apis/#typedefdef-clipboarditemdata

Related discussion is w3c/clipboard-apis#102
However it's not clear for me why IDL "implies" that non-promise value is OK

[Bahman-66]

I manipulated the lib file so ClipboardItem constructor accepted any types for items and also the Clipbard.write method accept any parameter the results is as follow:

linux machine

• chrome

TypeError: Failed to construct 'ClipboardItem': Failed to convert value to 'Blob'.

• firefox

ReferenceError: ClipboardItem is not defined

-edge beta version
successfully copied the image from blob to clipboard

windows machine

all of them fails similar to firefox and chrome on linux

[andrewbranch]

Can you show exactly what change you are proposing to make to what definition? I’m finding this kind of hard to follow without going and looking up a bunch of stuff.

[IllusionMH]

I think changes are already in place: error in 4.4.3 and works in Nightly
Previously argument was

Record<string, ClipboardItemData>

but in Nightly it's

Record<string, ClipboardItemDataType | PromiseLike<ClipboardItemDataType>>

[IllusionMH]

It was fixed in microsoft/TypeScript-DOM-lib-generator#1102

And there is further PR to leave only Blob at this moment microsoft/TypeScript-DOM-lib-generator#1139

I believe this issue can be closed (but I'm not reporter).

[andrewbranch]

Thanks @IllusionMH!