@graphql-tools/graphql/esm/validation/rules/UniqueFragmentNamesRule.js

Fork of GraphQL.js

import { GraphQLError } from '../../error/GraphQLError.js';
/**
 * Unique fragment names
 *
 * A GraphQL document is only valid if all defined fragments have unique names.
 *
 * See https://spec.graphql.org/draft/#sec-Fragment-Name-Uniqueness
 */
export function UniqueFragmentNamesRule(context) {
    const knownFragmentNames = Object.create(null);
    return {
        OperationDefinition: () => false,
        FragmentDefinition(node) {
            const fragmentName = node.name.value;
            if (knownFragmentNames[fragmentName]) {
                context.reportError(new GraphQLError(`There can be only one fragment named "${fragmentName}".`, {
                    nodes: [knownFragmentNames[fragmentName], node.name],
                }));
            }
            else {
                knownFragmentNames[fragmentName] = node.name;
            }
            return false;
        },
    };
}