String? _test()

in lib/src/iterable_matchers.dart [154:194]

• 37 lines of code
• 11 McCabe index (conditional complexity)

  String? _test(List values) {
    // Check the lengths are the same.
    if (_expected.length > values.length) {
      return 'has too few elements (${values.length} < ${_expected.length})';
    } else if (!_allowUnmatchedValues && _expected.length < values.length) {
      return 'has too many elements (${values.length} > ${_expected.length})';
    }

    var edges = List.generate(values.length, (_) => <int>[], growable: false);
    for (var v = 0; v < values.length; v++) {
      for (var m = 0; m < _expected.length; m++) {
        if (_expected[m].matches(values[v], {})) {
          edges[v].add(m);
        }
      }
    }
    // The index into `values` matched with each matcher or `null` if no value
    // has been matched yet.
    var matched = List<int?>.filled(_expected.length, null);
    for (var valueIndex = 0; valueIndex < values.length; valueIndex++) {
      _findPairing(edges, valueIndex, matched);
    }
    for (var matcherIndex = 0;
        matcherIndex < _expected.length;
        matcherIndex++) {
      if (matched[matcherIndex] == null) {
        final description = StringDescription()
            .add('has no match for ')
            .addDescriptionOf(_expected[matcherIndex])
            .add(' at index $matcherIndex');
        final remainingUnmatched =
            matched.sublist(matcherIndex + 1).where((m) => m == null).length;
        return remainingUnmatched == 0
            ? description.toString()
            : description
                .add(' along with $remainingUnmatched other unmatched')
                .toString();
      }
    }
    return null;
  }