Type Alias GrepMatches<CountOnly>

GrepMatches: IsEqual<CountOnly, true> extends true
    ? { [FileName in string]: number }
    : IsEqual<CountOnly, false> extends true
        ? { [FileName in string]: string[] }
        : { [FileName in string]: number } | { [FileName in string]: string[] }

Output of grep. Each key is a file path returned by grep. Values are arrays of matched lines for that file.