Example:
function a(...args: ???type of b() params???) {
b(...args)
}
I want args to be type of b's parameters.
If you want to know why would I want that, then it is for code readability/incapsulation. b is imported function, and I don't care about its implementation at the level of function a declaration
You can do this in 3.0 Tuples in rest parameters and spread expressions (in RC right now should be out soon)
type ArgumentType<T> = T extends (...args: infer U) => any ? U : never;
function a(...args: ArgumentType<typeof b>) {
function b(...args: any[]) {
}
}
// More complex examples
function a2(...args: ArgumentType<typeof b>) {
function b(name: string, value: number) {
}
}
a2("", 1);
This is possible another way now:
function a(...args: Parameters<typeof b>) {
b(...args);
}
