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

Fork of GraphQL.js

import { GraphQLError } from '../../error/GraphQLError.js';
import { print } from '../../language/printer.js';
import { isCompositeType } from '../../type/definition.js';
import { typeFromAST } from '../../utilities/typeFromAST.js';
/**
 * Fragments on composite type
 *
 * Fragments use a type condition to determine if they apply, since fragments
 * can only be spread into a composite type (object, interface, or union), the
 * type condition must also be a composite type.
 *
 * See https://spec.graphql.org/draft/#sec-Fragments-On-Composite-Types
 */
export function FragmentsOnCompositeTypesRule(context) {
    return {
        InlineFragment(node) {
            const typeCondition = node.typeCondition;
            if (typeCondition) {
                const type = typeFromAST(context.getSchema(), typeCondition);
                if (type && !isCompositeType(type)) {
                    const typeStr = print(typeCondition);
                    context.reportError(new GraphQLError(`Fragment cannot condition on non composite type "${typeStr}".`, { nodes: typeCondition }));
                }
            }
        },
        FragmentDefinition(node) {
            const type = typeFromAST(context.getSchema(), node.typeCondition);
            if (type && !isCompositeType(type)) {
                const typeStr = print(node.typeCondition);
                context.reportError(new GraphQLError(`Fragment "${node.name.value}" cannot condition on non composite type "${typeStr}".`, {
                    nodes: node.typeCondition,
                }));
            }
        },
    };
}