GherkinExpression constructor

GherkinExpression(RegExp originalExpression, Iterable<CustomParameter> customParameters)

Implementation

GherkinExpression(
  this.originalExpression,
  Iterable<CustomParameter<dynamic>> customParameters,
) {
  var pattern = originalExpression.pattern;
  customParameters.forEach((p) {
    if (originalExpression.pattern.contains(p.identifier)) {
      // we need the index in the original pattern to be able to
      // transform the parameter into the correct type later on
      // so get that then modify the new matching pattern.
      originalExpression.pattern.replaceAllMapped(
          RegExp(_escapeIdentifier(p.identifier),
              caseSensitive: true, multiLine: true), (m) {
        _sortedParameterPositions.add(_SortedParameterPosition(m.start, p));

        return m.input;
      });
      pattern = pattern.replaceAllMapped(
          RegExp(_escapeIdentifier(p.identifier),
              caseSensitive: true, multiLine: true),
          (m) => p.pattern.pattern);
    }
  });

  // check for any capture patterns that are not custom parameters
  // but defined directly in the step definition for example:
  //  Given I (open|close) the drawer(s)
  // note that we should ignore the predefined (s) plural parameter
  // and also ignore the (?:) non-capturing group pattern
  var inCustomBracketSection = false;
  int? indexOfOpeningBracket;
  for (var i = 0; i < originalExpression.pattern.length; i += 1) {
    final char = originalExpression.pattern[i];
    if (char == '(') {
      // look ahead and make sure we don't see "s)" or "?:" which would
      // indicate the plural parameter or a non-capturing group
      if (originalExpression.pattern.length > i + 2) {
        final justAhead = originalExpression.pattern[i + 1] +
            originalExpression.pattern[i + 2];
        if (justAhead != 's)' && justAhead != '?:') {
          inCustomBracketSection = true;
          indexOfOpeningBracket = i;
        }
      }
    } else if (char == ')' && inCustomBracketSection) {
      _sortedParameterPositions.add(
        _SortedParameterPosition(
          indexOfOpeningBracket!,
          UserDefinedStepParameterParameter(),
        ),
      );
      inCustomBracketSection = false;
      indexOfOpeningBracket = 0;
    }
  }

  _sortedParameterPositions.sort((a, b) => a.startPosition - b.startPosition);
  _expression = RegExp(pattern,
      caseSensitive: originalExpression.isCaseSensitive,
      multiLine: originalExpression.isMultiLine);
}