JSDoc @this does not propagate to the actual type of a function #44461
Description
Bug Report
When using @this to annotate a function, the underlying type of that function does not reflect the TypeScript equivalent properly when used as a type elsewhere.
🔎 Search Terms
function this jsdoc
🕗 Version & Regression Information
- This is the behavior in every version I tried, and I reviewed the FAQ for entries about JSDoc
⏯ Playground Link
Playground link with relevant code
💻 Code
You should test this out in VSCode, as the Play link appears to handle a few things incorrectly.
// Note: hovering over `someCallback` shows in annotation that
// the type of `this` is *, which is weird
// Also note a secondary bug that `someCallback` is assumed to be
// a constructor, even though it isn't, and there is no way
// to override it.
/**
* @this {HTMLElement}
* @param {MouseEvent} e
*/
function someCallback(e)
{
this.textContent = 'hello';
}
// Note: this does not seem to work in Play, but VSCode
// seems to handle @type properly here. The only issue is
// that someCallback does not seem to have a proper `this` type.
/** @type {typeof someCallback} */
function equivalentType(e)
{
// `this` is "any". In VSCode, `e` has the correct type,
// but `this` is untyped.
someCallback.call(this, e);
}
// This should be equivalent to the function above & to someCallback, but is not.
// This is the correct type for `typeof someCallback`, however.
/** @type {(this: HTMLElement, e: MouseEvent) => void} */
function actualEquivalentType(e)
{
// "this" is typed properly
someCallback.call(this, e);
}🙁 Actual behavior
typeof someCallback does not include the this JSDoc component, and is typed as (e: MouseEvent) => void
🙂 Expected behavior
typeof someCallback should be (this: HTMLElement, e: MouseEvent) => void