TypedArray is missing from lib.dom

[trusktr]

⚙ Compilation target

n/a

⚙ Library

lib.dom.d.ts

Missing / Incorrect Definition

TypedArray is missing from typed array classes.

Sample Code

In all browsers, this works:

console.log(Float64Array.__proto__) // Logs the "TypedArray" constructor.

Currently that code gives the type error

Property '__proto__' does not exist on type 'Float64ArrayConstructor'. ts(2339)

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray

The MDN doc mentions:

There is no global property named TypedArray, nor is there a directly visible TypedArray constructor

However that appears to be untrue in all browsers, TypedArray is visible on the prototype of any typed array constructor.

It would be nice if lib.dom was able to represent this class somehow, such that it would be possible to do the following to make it easy to reference the base class:

const TypedArray = Float32Array.__proto__

console.log(new Float64Array() instanceof TypedArray) // logs "true" in all browsers
console.log(new Int8Array() instanceof TypedArray) // logs "true" in all browsers
console.log(new Int16Array() instanceof TypedArray) // logs "true" in all browsers
console.log(new Int32Array() instanceof TypedArray) // logs "true" in all browsers
console.log(new Uint8Array() instanceof TypedArray) // logs "true" in all browsers
console.log(new BigInt64Array() instanceof TypedArray) // logs "true" in all browsers

This would also simplify certain functions, for example:

function doSomethingWithTypedArray(array: TypedArray) {
  // ...Does something with any sort of typed array...
}

[MartinJohns]

Duplicate of #15402.

[nmain]

You're reporting two separate issues here:

• There is no type definition for the thing commonly known as TypedArray. This is tracked in Suggestion: a built-in TypedArray interface #15402 as noted above.
• __proto__ is not modeled in typescript at all.
  • Even if the above issue is fixed, Float32Array.__proto__ won't work as __proto__ is never connected in Typescript, even on types that have nothing to do with typed arrays: Playground example
  • This is tracked in TS2339: Property '__proto__' does not exist on type 'typeof A1'. #30587.

However that appears to be untrue in all browsers,

On a side note, I think what MDN means by "directly visible" is just that globalThis.TypedArray does not exist, not that the value is unobservable by any means.