uniqueArgumentNamesRule function

Visitor uniqueArgumentNamesRule(SDLValidationCtx context)

Unique argument names

A GraphQL field or directive is only valid if all supplied arguments are uniquely named.

See https://spec.graphql.org/draft/#sec-Argument-Names

Implementation

Visitor uniqueArgumentNamesRule(
  SDLValidationCtx context, // ASTValidationContext,
) {
  final visitor = TypedVisitor();

  VisitBehavior? checkArgUniqueness(List<ArgumentNode> argumentNodes) {
    final seenArgs = argumentNodes.groupListsBy((arg) => arg.name.value);

    for (final entry in seenArgs.entries) {
      if (entry.value.length > 1) {
        context.reportError(
          GraphQLError(
            'There can be only one argument named "${entry.key}".',
            locations: List.of(entry.value
                .map((node) => node.name.span!.start)
                .map((e) => GraphQLErrorLocation.fromSourceLocation(e))),
            extensions: _uniqueArgumentNamesSpec.extensions(),
          ),
        );
      }
    }
  }

  visitor.add<FieldNode>((node) => checkArgUniqueness(node.arguments));
  visitor.add<DirectiveNode>((node) => checkArgUniqueness(node.arguments));
  return visitor;
}