microsoft/TypeScript

Support InputEvent interface in libs

Christian24 opened this issue ยท 4 comments

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.

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

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.

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.

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