Missing empty string in .d.ts parameters for non-string types in attributes

[BalagePMI]

The problem

The .d.ts (typescript mapper) for Shape and many other data types are not supporting string (or at least empty string constant) as input.

For example, the following declaration

 fillPatternImage: GetSet<HTMLImageElement | HTMLCanvasElement, this>;

only allows Image and Canvas types as input.
Clearing a pattern fill could be by passing the fillPatternImage an empty string (it could be undefined, but it may be some design decision), which is marked as uncompatible value. So using this one hase to add a @ts-ignore which is an antipattern and also may generates a warning itself in strict mode.

The same goes on any other field, so the code is polluted with @ts-ignore:

 // @ts-ignore
 this._node.fill('')
 // @ts-ignore
 this._node.fillPatternImage('')
 // @ts-ignore
 this._node.fillLinearGradientColorStops('')
 // @ts-ignore
 this._node.fillRadialGradientColorStops('')

The suggestion

The values which receives non string values should be extended with empty string pattern as input.

 fillPatternImage: GetSet<HTMLImageElement | HTMLCanvasElement | '', this>;

This solution has only impact on the .d.ts files.
Accepting undefined and/or null may be even cleaner. However, it has a great impact on the base JS code.

[lavrton]

I dont think empty string is a good value. While it is working in runtime because it is falsy, I think the more consistent value should be null

[BalagePMI]

Yes, null or even more undefined is better, but the current definition doesn't let it either.

So my proposal is to change the

 fillPatternImage: GetSet<HTMLImageElement | HTMLCanvasElement | undefined, this>;

the signature (and for all fields).