Map _parseDependencies()

in lib/src/pubspec.dart [415:504]
71 lines of code
17 McCabe index (conditional complexity)

  Map<String, PackageRange> _parseDependencies(String field, YamlNode? node) {
    var dependencies = <String, PackageRange>{};

    // Allow an empty dependencies key.
    if (node == null || node.value == null) return dependencies;

    if (node is! YamlMap) {
      _error('"$field" field must be a map.', node.span);
    }

    var nonStringNode = node.nodes.keys
        .firstWhere((e) => e.value is! String, orElse: () => null);
    if (nonStringNode != null) {
      _error('A dependency name must be a string.', nonStringNode.span);
    }

    node.nodes.forEach((nameNode, specNode) {
      var name = nameNode.value;
      var spec = specNode.value;
      if (fields['name'] != null && name == this.name) {
        _error('A package may not list itself as a dependency.', nameNode.span);
      }

      YamlNode? descriptionNode;
      String? sourceName;

      VersionConstraint versionConstraint = VersionRange();
      var features = const <String, FeatureDependency>{};
      if (spec == null) {
        sourceName = _sources!.defaultSource.name;
      } else if (spec is String) {
        sourceName = _sources!.defaultSource.name;
        versionConstraint = _parseVersionConstraint(specNode);
      } else if (spec is Map) {
        // Don't write to the immutable YAML map.
        spec = Map.from(spec);
        var specMap = specNode as YamlMap;

        if (spec.containsKey('version')) {
          spec.remove('version');
          versionConstraint = _parseVersionConstraint(specMap.nodes['version']);
        }

        if (spec.containsKey('features')) {
          spec.remove('features');
          features = _parseDependencyFeatures(specMap.nodes['features']);
        }

        var sourceNames = spec.keys.toList();
        if (sourceNames.length > 1) {
          _error('A dependency may only have one source.', specNode.span);
        } else if (sourceNames.isEmpty) {
          // Default to a hosted dependency if no source is specified.
          sourceName = 'hosted';
        }

        sourceName ??= sourceNames.single;
        if (sourceName is! String) {
          _error('A source name must be a string.',
              specMap.nodes.keys.single.span);
        }

        descriptionNode ??= specMap.nodes[sourceName];
      } else {
        _error('A dependency specification must be a string or a mapping.',
            specNode.span);
      }

      // Let the source validate the description.
      var ref = _wrapFormatException('description', descriptionNode?.span, () {
        String? pubspecPath;
        var location = _location;
        if (location != null && _isFileUri(location)) {
          pubspecPath = path.fromUri(_location);
        }

        return _sources![sourceName]!.parseRef(
          name,
          descriptionNode?.value,
          containingPath: pubspecPath,
          languageVersion: languageVersion,
        );
      }, targetPackage: name);

      dependencies[name] =
          ref.withConstraint(versionConstraint).withFeatures(features);
    });

    return dependencies;
  }