graphql/validation/rules/UniqueOperationTypes.mjs

A Query Language and Runtime which can target any service.

import { GraphQLError } from '../../error/GraphQLError';
export function duplicateOperationTypeMessage(operation) {
  return "There can be only one ".concat(operation, " type in schema.");
}
export function existedOperationTypeMessage(operation) {
  return "Type for ".concat(operation, " already defined in the schema. It cannot be redefined.");
}
/**
 * Unique operation types
 *
 * A GraphQL document is only valid if it has only one type per operation.
 */

export function UniqueOperationTypes(context) {
  var schema = context.getSchema();
  var definedOperationTypes = Object.create(null);
  var existingOperationTypes = schema ? {
    query: schema.getQueryType(),
    mutation: schema.getMutationType(),
    subscription: schema.getSubscriptionType()
  } : {};
  return {
    SchemaDefinition: checkOperationTypes,
    SchemaExtension: checkOperationTypes
  };

  function checkOperationTypes(node) {
    if (node.operationTypes) {
      var _iteratorNormalCompletion = true;
      var _didIteratorError = false;
      var _iteratorError = undefined;

      try {
        for (var _iterator = (node.operationTypes || [])[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
          var operationType = _step.value;
          var operation = operationType.operation;
          var alreadyDefinedOperationType = definedOperationTypes[operation];

          if (existingOperationTypes[operation]) {
            context.reportError(new GraphQLError(existedOperationTypeMessage(operation), operationType));
          } else if (alreadyDefinedOperationType) {
            context.reportError(new GraphQLError(duplicateOperationTypeMessage(operation), [alreadyDefinedOperationType, operationType]));
          } else {
            definedOperationTypes[operation] = operationType;
          }
        }
      } catch (err) {
        _didIteratorError = true;
        _iteratorError = err;
      } finally {
        try {
          if (!_iteratorNormalCompletion && _iterator.return != null) {
            _iterator.return();
          }
        } finally {
          if (_didIteratorError) {
            throw _iteratorError;
          }
        }
      }
    }

    return false;
  }
}