compile method

Implementation

String compile() {
  final argumentsInCommand = _positionalArgumentsRegexp.allMatches(command);

  if (argumentsInCommand.isNotEmpty) {
    if (isHook) {
      throw RpsException(
        'The script "$path" defines a positional argument(s), '
        'but hooks do not support positional arguments.',
      );
    }

    final usedArguments = <int>{};
    final filledCommand = command.replaceAllMapped(
      _positionalArgumentsRegexp,
      (match) {
        final content = match.group(0)!;
        final value = content.substring(2, content.length - 1).trim();
        final argumentIndex = int.tryParse(value);
        if (argumentIndex == null) {
          throw RpsException(
            "Bad argument script ($content). "
            "Only positional arguments are supported.",
          );
        } else if (argumentIndex >= arguments.length) {
          throw RpsException(
            'The script "$path" defines a positional argument $content, '
            'but ${arguments.length} positional argument(s) are given.',
          );
        } else {
          usedArguments.add(argumentIndex);
          return arguments[argumentIndex];
        }
      },
    );

    final lastUsed = usedArguments.reduce(math.max);
    if (lastUsed > usedArguments.length) {
      final unusedArguments = List<int>.generate(lastUsed, (index) => index)
          .where((e) => !usedArguments.contains(e));

      throw RpsException(
        'The script defines unused positional argument(s): '
        '${unusedArguments.map((a) => '\${$a}').join(', ')}',
      );
    }

    return [filledCommand, ...arguments.sublist(lastUsed + 1)].join(' ');
  } else {
    return [command, ...arguments].join(' ');
  }
}