[TypeScript] Types for JavaScript's replacerFunction in String.prototype.replaceAll

regex.ts

export interface ReplacerArgs {
    match: string; // the matched substring
    groups: string[]; // captured groups
    offset: number; // offset of match
    string: string; // entire string
    named_groups?: Record<string, string>; // named capturing groups
}

function parseReplacerArgsMutating(args: [string, ...any[]]): ReplacerArgs {
    const named_groups = typeof args[args.length - 1] === 'object' ? (args.pop() as Record<string, string>) : undefined;
    const string = args.pop() as string;
    const offset = args.pop() as number;
    const match = args[0];
    const groups = args.slice(1) as string[];

    return {match, groups, offset, string, named_groups};
}

export function parseReplacerArgs(args: [string, ...any[]]): ReplacerArgs {
    return parseReplacerArgsMutating([...args]);
}