Improve HTMLImageElement.loading

[quinnlangille]

lib Update Request

Configuration Check

My compilation target is ES2015 and my lib is the default.

Missing / Incorrect Definition

HTMLImageElement.loading is currently a string, but the only valid values for it are eager and lazy

Sample Code

While the string works, it allows for invalid values. ex:

<img loading="random value" />

is valid, as well as:

interface ImageWrapper {
  image: HTMLImageElement
}

const imageWrapper: ImageWrapper = { image: new HTMLImageElement() }
imageWrapper.image.loading = 'random value'

I would expect both of these cases to throw a warning at least on invalid/not useful value

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement/loading

[quinnlangille]

If everyone is in favour of making this change, I can open a PR anytime

[MartinJohns]

microsoft/TypeScript-DOM-lib-generator#747

From the issue template for lib change requests:

The DOM lib is maintained elsewhere and you can skip a step by filing issues/PRs for the DOM at that repo.
See https://github.com/microsoft/TypeScript-DOM-lib-generator

[jakebailey]

This was fixed in #47445.