Type Alias String<From, To>

String: string extends To
    ? _StringUnknown
    : string extends From
        ? _StringUnknown
        : To extends From
            ? _EQ
            : To extends `${infer Before}${From}${infer After}`
                ? { add: true; after: After; before: Before; result: "substring" }
                : From extends `${infer Before}${To}${infer After}`
                    ? { add: false; after: After; before: Before; result: "substring" }
                    : { result: "not-equal" }