VoidFunction interface should be defined for ES5 target

[galkin]

⚙ Compilation target

ES5

⚙ Library

lib.es5.d.ts

Missing / Incorrect Definition

In lib.dom.d.ts and similar files produced by TypeScript-DOM-lib-generator we have:

interface VoidFunction {
    (): void;
}

This interface is commonly used for frontend development, but it is not defined with recommended Node.js configuration

Adding this interface to lib.es5.d.ts will simplify FullStack practices

Sample Code

type props = {
  handle: voidFunction;
}

Documentation Link

No response

[galkin]

@sandersn, could you provide your opinion about this tiny issue? I linked a fix.
I don't think we need any changes in TypeScript-DOM-lib-generator, but adding to es5 will also provide Node.js dev use the interface.

[jakebailey]

We don't add helper types they're required for dts emit; I don't think we would add this.

[galkin]

@jakebailey, helper types like those in dom.lib have been widely used by the TypeScript community.

However, Node.js developers face a challenge since dom.lib isn’t used, and we often need to recreate these helpers in every project. What does the TypeScript team recommend to address this?

1. Should we propose moving or adding these helpers from dom to es5?
2. Should we add them to @types/node?
3. Or, should we create a new package for these helpers and promote it?

For now, I’ve only identified VoidFunction, but there might be others. I’d appreciate your guidance!

[jakebailey]

helper types like those in dom.lib have been widely used by the TypeScript community.

Being widely used does not mean we add them for everyone.

Notably, https://github.com/search?q=%2F%5CbVoidFunction%5Cb%2F+language%3ATypeScript&type=code shows that most uses of this name are people declaring the type, not using the one from the DOM types.

To your three questions, my personal opinion is "no" for all three. This is a one line type; most people would not declare type VoidFunction = () => void, when they can just type () => void directly, which is shorter and clearer.

[galkin]

it makes sense. I'm closing the issue and the PR. Thanks for your time!