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

Fork of GraphQL.js

import { GraphQLError } from '../../error/GraphQLError.js';
import { Kind } from '../../language/kinds.js';
import { isTypeDefinitionNode, isTypeExtensionNode } from '../../language/predicates.js';
import { specifiedDirectives } from '../../type/directives.js';
/**
 * Unique directive names per location
 *
 * A GraphQL document is only valid if all non-repeatable directives at
 * a given location are uniquely named.
 *
 * See https://spec.graphql.org/draft/#sec-Directives-Are-Unique-Per-Location
 */
export function UniqueDirectivesPerLocationRule(context) {
    const uniqueDirectiveMap = Object.create(null);
    const schema = context.getSchema();
    const definedDirectives = schema ? schema.getDirectives() : specifiedDirectives;
    for (const directive of definedDirectives) {
        uniqueDirectiveMap[directive.name] = !directive.isRepeatable;
    }
    const astDefinitions = context.getDocument().definitions;
    for (const def of astDefinitions) {
        if (def.kind === Kind.DIRECTIVE_DEFINITION) {
            uniqueDirectiveMap[def.name.value] = !def.repeatable;
        }
    }
    const schemaDirectives = Object.create(null);
    const typeDirectivesMap = Object.create(null);
    return {
        // Many different AST nodes may contain directives. Rather than listing
        // them all, just listen for entering any node, and check to see if it
        // defines any directives.
        enter(node) {
            if (!('directives' in node) || !node.directives) {
                return;
            }
            let seenDirectives;
            if (node.kind === Kind.SCHEMA_DEFINITION || node.kind === Kind.SCHEMA_EXTENSION) {
                seenDirectives = schemaDirectives;
            }
            else if (isTypeDefinitionNode(node) || isTypeExtensionNode(node)) {
                const typeName = node.name.value;
                seenDirectives = typeDirectivesMap[typeName];
                if (seenDirectives === undefined) {
                    typeDirectivesMap[typeName] = seenDirectives = Object.create(null);
                }
            }
            else {
                seenDirectives = Object.create(null);
            }
            for (const directive of node.directives) {
                const directiveName = directive.name.value;
                if (uniqueDirectiveMap[directiveName]) {
                    if (seenDirectives[directiveName]) {
                        context.reportError(new GraphQLError(`The directive "@${directiveName}" can only be used once at this location.`, {
                            nodes: [seenDirectives[directiveName], directive],
                        }));
                    }
                    else {
                        seenDirectives[directiveName] = directive;
                    }
                }
            }
        },
    };
}