reselect
Version:
Selectors for Redux.
25 lines (24 loc) • 1.61 kB
TypeScript
import { ReverseHead, ReverseTail } from '../types';
type UnknownFunction = (...args: any[]) => any;
type LongestTuple<T> = T extends [infer U extends unknown[]] ? U : T extends [infer U, ...infer R extends unknown[][]] ? MostProperties<U, LongestTuple<R>> : never;
type MostProperties<T, U> = keyof U extends keyof T ? T : U;
type ElementAt<T, N extends keyof any> = N extends keyof T ? T[N] : unknown;
type ElementsAt<T, N extends keyof any> = {
[K in keyof T]: ElementAt<T[K], N>;
};
type Intersect<T extends readonly unknown[]> = T extends [] ? unknown : T extends [infer H, ...infer T] ? H & Intersect<T> : T[number];
type MergeTuples<T, L extends unknown[] = LongestTuple<T>> = {
[K in keyof L]: Intersect<ElementsAt<T, K> extends readonly unknown[] ? ElementsAt<T, K> : never>;
};
type ExtractParameters<T extends readonly UnknownFunction[]> = {
[K in keyof T]: Parameters<T[K]>;
};
export type MergeParameters<T extends readonly UnknownFunction[]> = '0' extends keyof T ? MergeTuples<MakeRestExplicit<ExtractParameters<T>>> : Parameters<T[number]>;
type HasRest<S extends readonly unknown[]> = number extends S['length'] ? true : false;
type HasExplicit<S extends readonly unknown[]> = '0' extends keyof S ? true : false;
type HasCombined<S extends readonly unknown[]> = true extends HasExplicit<S> & HasRest<S> ? true : false;
type MakeRestExplicit<T extends readonly unknown[][]> = true extends HasCombined<T> ? [
...ReverseTail<T>,
ReverseHead<T> extends readonly unknown[] ? ReverseHead<T>[number] : never
] : true extends HasRest<T> ? [...T] : T;
export {};