Support InputEvent interface in libs

[Christian24]

Search Terms

input event
InputEvent

Suggestion

TypeScript so far does not have a type definition of InputEvent (https://developer.mozilla.org/en-US/docs/Web/API/InputEvent). Even though there are some bugs concerning browser support, I would still say it is supported widely enough (https://caniuse.com/#feat=input-event) to be part of TypeScript's libs. So, far there only is a type definition available through @types/dom-inputevent

Use Cases

Working with input elements in HTML5. It's a feature of HTML5 and thus should be supported.

Examples

(event: InputEvent) => this.value = event.currentTarget.value;

Checklist

My suggestion meets these guidelines:

• [x ] This wouldn't be a breaking change in existing TypeScript/JavaScript code
• [ x] This wouldn't change the runtime behavior of existing JavaScript code
• [x ] This could be implemented without emitting different JS based on the types of the expressions
• [x ] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• [ x] This feature would agree with the rest of TypeScript's Design Goals.

[RyanCavanaugh]

We don't add definitions into the built-in lib.dom until they leave the Experimental phase.

[Christian24]

Okay, thanks. I understand. However, in this case I do not really agree, InputEvent is available since IE9, so web developers have had lots of time to use it, so it is desirable to have typing support for it.

[akoidan]

That's unfortunate because code like this breaks everything in Edge 15:
tsconfig.json:

{
  "experimentalDecorators": true,
}

index.ts:

class A {
  a(b: InputEvent) {
  }
}

Not that obvious that typings could break a class declaration... Also, note that bundlers like webpack would pack declarations to main method, which would throw an error immediately making customers unhappy :(

Here's the related issue.

[michahell]

Why is this something that is in 'Experimental' phase?