Arbitrary arity pipe function typings

pipe.ts

type UnaryFunction<T, R> = (source: T) => R;

type Pipe<T, L = void, R extends UnaryFunction<any, any>[] = []> =
    T extends []
        ? R
        : L extends void
            ? T extends [(_: infer P) => infer V, ...infer Rest]
                ? Pipe<Rest, V, [...R, UnaryFunction<P, V>]>
                : never[]
            : T extends [(_: L) => infer V, ...infer Rest]
                ? Pipe<Rest, V, [...R, UnaryFunction<L, V>]>
                : never[]
;

type Compose<A> = A extends [UnaryFunction<infer S, any>, ...UnaryFunction<any, any>[], UnaryFunction<any, infer V>] ? UnaryFunction<S, V> : never;

type Valid<A> = A extends UnaryFunction<any, any>[] ? Pipe<A> extends never[] ? never[] : A : never[];

declare function pipe<A extends UnaryFunction<any, any>[]>(...fns: Valid<A>): Compose<Pipe<A>>;

pipe(
    (_: string) => 0,
    (_: number) => "",
    (_: string) => true,
);

note: haven't gotten to validation of arguments yet

now added :)