graphql/validation/rules/UniqueDirectivesPerLocation.mjs

A Query Language and Runtime which can target any service.

import { GraphQLError } from '../../error/GraphQLError';
import { Kind } from '../../language/kinds';
import { specifiedDirectives } from '../../type/directives';
export function duplicateDirectiveMessage(directiveName) {
  return "The directive \"".concat(directiveName, "\" can only be used once at this location.");
}
/**
 * Unique directive names per location
 *
 * A GraphQL document is only valid if all non-repeatable directives at
 * a given location are uniquely named.
 */

export function UniqueDirectivesPerLocation(context) {
  var uniqueDirectiveMap = Object.create(null);
  var schema = context.getSchema();
  var definedDirectives = schema ? schema.getDirectives() : specifiedDirectives;

  for (var _i2 = 0; _i2 < definedDirectives.length; _i2++) {
    var directive = definedDirectives[_i2];
    uniqueDirectiveMap[directive.name] = !directive.isRepeatable;
  }

  var astDefinitions = context.getDocument().definitions;

  for (var _i4 = 0; _i4 < astDefinitions.length; _i4++) {
    var def = astDefinitions[_i4];

    if (def.kind === Kind.DIRECTIVE_DEFINITION) {
      uniqueDirectiveMap[def.name.value] = !def.repeatable;
    }
  }

  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: function enter(node) {
      // Flow can't refine that node.directives will only contain directives,
      // so we cast so the rest of the code is well typed.
      var directives = node.directives;

      if (directives) {
        var knownDirectives = Object.create(null);

        for (var _i6 = 0; _i6 < directives.length; _i6++) {
          var _directive = directives[_i6];
          var directiveName = _directive.name.value;

          if (uniqueDirectiveMap[directiveName]) {
            if (knownDirectives[directiveName]) {
              context.reportError(new GraphQLError(duplicateDirectiveMessage(directiveName), [knownDirectives[directiveName], _directive]));
            } else {
              knownDirectives[directiveName] = _directive;
            }
          }
        }
      }
    }
  };
}