type RemoveFromTuple<
Tuple extends readonly unknown[],
RemoveCount extends number,
Index extends 1[] = []
> = Index["length"] extends RemoveCount
? Tuple
: Tuple extends [infer First, ...infer Rest]
? RemoveFromTuple<Rest, RemoveCount, [...Index, 1]>
: Tuple;
type ConcatTuples<
Prefix extends readonly unknown[],
Suffix extends readonly unknown[]
> = [...Prefix, ...Suffix];
type ExtractFunctionParams<T> = T extends (this: infer TThis, ...args: infer P extends readonly unknown[]) => infer R
? { thisArg: TThis; params: P; returnType: R }
: never;
type BindFunction<
T extends (this: any, ...args: any[]) => any,
TThis,
TBoundArgs extends readonly unknown[],
ReceiverBound extends boolean
> = ExtractFunctionParams<T> extends {
thisArg: infer OrigThis;
params: infer P extends readonly unknown[];
returnType: infer R;
}
? ReceiverBound extends true
? (...args: RemoveFromTuple<P, Extract<TBoundArgs["length"], number>>) => R extends [OrigThis, ...infer Rest]
? [TThis, ...Rest] // Replace `this` with `thisArg`
: R
: <U, RemainingArgs extends RemoveFromTuple<P, Extract<TBoundArgs["length"], number>>>(
thisArg: U,
...args: RemainingArgs
) => R extends [OrigThis, ...infer Rest]
? [U, ...ConcatTuples<TBoundArgs, Rest>] // Preserve bound args in return type
: R
: never;
declare function callBind<
const T extends (this: any, ...args: any[]) => any,
Extracted extends ExtractFunctionParams<T>,
const TBoundArgs extends Partial<Extracted["params"]> & readonly unknown[],
const TThis extends Extracted["thisArg"]
>(
args: [fn: T, thisArg: TThis, ...boundArgs: TBoundArgs]
): BindFunction<T, TThis, TBoundArgs, true>;
declare function callBind<
const T extends (this: any, ...args: any[]) => any,
Extracted extends ExtractFunctionParams<T>,
const TBoundArgs extends Partial<Extracted["params"]> & readonly unknown[]
>(
args: [fn: T, ...boundArgs: TBoundArgs]
): BindFunction<T, Extracted["thisArg"], TBoundArgs, false>;
declare function callBind<const TArgs extends readonly unknown[]>(
args: [fn: Exclude<TArgs[0], Function>, ...rest: TArgs]
): never;
// export as namespace callBind;
export = callBind;