"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); exports.execute = execute; exports.assertValidExecutionArguments = assertValidExecutionArguments; exports.buildExecutionContext = buildExecutionContext; exports.collectFields = collectFields; exports.buildResolveInfo = buildResolveInfo; exports.resolveFieldValueOrError = resolveFieldValueOrError; exports.getFieldDef = getFieldDef; exports.defaultFieldResolver = exports.defaultTypeResolver = void 0; var _iterall = require("iterall"); var _inspect = _interopRequireDefault(require("../jsutils/inspect")); var _memoize = _interopRequireDefault(require("../jsutils/memoize3")); var _invariant = _interopRequireDefault(require("../jsutils/invariant")); var _devAssert = _interopRequireDefault(require("../jsutils/devAssert")); var _isInvalid = _interopRequireDefault(require("../jsutils/isInvalid")); var _isNullish = _interopRequireDefault(require("../jsutils/isNullish")); var _isPromise = _interopRequireDefault(require("../jsutils/isPromise")); var _isObjectLike = _interopRequireDefault(require("../jsutils/isObjectLike")); var _promiseReduce = _interopRequireDefault(require("../jsutils/promiseReduce")); var _promiseForObject = _interopRequireDefault(require("../jsutils/promiseForObject")); var _Path = require("../jsutils/Path"); var _GraphQLError = require("../error/GraphQLError"); var _locatedError = require("../error/locatedError"); var _kinds = require("../language/kinds"); var _validate = require("../type/validate"); var _introspection = require("../type/introspection"); var _directives = require("../type/directives"); var _definition = require("../type/definition"); var _typeFromAST = require("../utilities/typeFromAST"); var _getOperationRootType = require("../utilities/getOperationRootType"); var _values = require("./values"); function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } function execute(argsOrSchema, document, rootValue, contextValue, variableValues, operationName, fieldResolver, typeResolver) { /* eslint-enable no-redeclare */ // Extract arguments from object args if provided. return arguments.length === 1 ? executeImpl(argsOrSchema) : executeImpl({ schema: argsOrSchema, document: document, rootValue: rootValue, contextValue: contextValue, variableValues: variableValues, operationName: operationName, fieldResolver: fieldResolver, typeResolver: typeResolver }); } function executeImpl(args) { var schema = args.schema, document = args.document, rootValue = args.rootValue, contextValue = args.contextValue, variableValues = args.variableValues, operationName = args.operationName, fieldResolver = args.fieldResolver, typeResolver = args.typeResolver; // If arguments are missing or incorrect, throw an error. assertValidExecutionArguments(schema, document, variableValues); // If a valid execution context cannot be created due to incorrect arguments, // a "Response" with only errors is returned. var exeContext = buildExecutionContext(schema, document, rootValue, contextValue, variableValues, operationName, fieldResolver, typeResolver); // Return early errors if execution context failed. if (Array.isArray(exeContext)) { return { errors: exeContext }; } // Return a Promise that will eventually resolve to the data described by // The "Response" section of the GraphQL specification. // // If errors are encountered while executing a GraphQL field, only that // field and its descendants will be omitted, and sibling fields will still // be executed. An execution which encounters errors will still result in a // resolved Promise. var data = executeOperation(exeContext, exeContext.operation, rootValue); return buildResponse(exeContext, data); } /** * Given a completed execution context and data, build the { errors, data } * response defined by the "Response" section of the GraphQL specification. */ function buildResponse(exeContext, data) { if ((0, _isPromise.default)(data)) { return data.then(function (resolved) { return buildResponse(exeContext, resolved); }); } return exeContext.errors.length === 0 ? { data: data } : { errors: exeContext.errors, data: data }; } /** * Essential assertions before executing to provide developer feedback for * improper use of the GraphQL library. */ function assertValidExecutionArguments(schema, document, rawVariableValues) { document || (0, _devAssert.default)(0, 'Must provide document'); // If the schema used for execution is invalid, throw an error. (0, _validate.assertValidSchema)(schema); // Variables, if provided, must be an object. rawVariableValues == null || (0, _isObjectLike.default)(rawVariableValues) || (0, _devAssert.default)(0, 'Variables must be provided as an Object where each property is a variable value. Perhaps look to see if an unparsed JSON string was provided.'); } /** * Constructs a ExecutionContext object from the arguments passed to * execute, which we will pass throughout the other execution methods. * * Throws a GraphQLError if a valid execution context cannot be created. */ function buildExecutionContext(schema, document, rootValue, contextValue, rawVariableValues, operationName, fieldResolver, typeResolver) { var operation; var hasMultipleAssumedOperations = false; var fragments = Object.create(null); for (var _i2 = 0, _document$definitions2 = document.definitions; _i2 < _document$definitions2.length; _i2++) { var definition = _document$definitions2[_i2]; switch (definition.kind) { case _kinds.Kind.OPERATION_DEFINITION: if (!operationName && operation) { hasMultipleAssumedOperations = true; } else if (!operationName || definition.name && definition.name.value === operationName) { operation = definition; } break; case _kinds.Kind.FRAGMENT_DEFINITION: fragments[definition.name.value] = definition; break; } } if (!operation) { if (operationName) { return [new _GraphQLError.GraphQLError("Unknown operation named \"".concat(operationName, "\"."))]; } return [new _GraphQLError.GraphQLError('Must provide an operation.')]; } if (hasMultipleAssumedOperations) { return [new _GraphQLError.GraphQLError('Must provide operation name if query contains multiple operations.')]; } var coercedVariableValues = (0, _values.getVariableValues)(schema, operation.variableDefinitions || [], rawVariableValues || {}, { maxErrors: 50 }); if (coercedVariableValues.errors) { return coercedVariableValues.errors; } return { schema: schema, fragments: fragments, rootValue: rootValue, contextValue: contextValue, operation: operation, variableValues: coercedVariableValues.coerced, fieldResolver: fieldResolver || defaultFieldResolver, typeResolver: typeResolver || defaultTypeResolver, errors: [] }; } /** * Implements the "Evaluating operations" section of the spec. */ function executeOperation(exeContext, operation, rootValue) { var type = (0, _getOperationRootType.getOperationRootType)(exeContext.schema, operation); var fields = collectFields(exeContext, type, operation.selectionSet, Object.create(null), Object.create(null)); var path = undefined; // Errors from sub-fields of a NonNull type may propagate to the top level, // at which point we still log the error and null the parent field, which // in this case is the entire response. // // Similar to completeValueCatchingError. try { var result = operation.operation === 'mutation' ? executeFieldsSerially(exeContext, type, rootValue, path, fields) : executeFields(exeContext, type, rootValue, path, fields); if ((0, _isPromise.default)(result)) { return result.then(undefined, function (error) { exeContext.errors.push(error); return Promise.resolve(null); }); } return result; } catch (error) { exeContext.errors.push(error); return null; } } /** * Implements the "Evaluating selection sets" section of the spec * for "write" mode. */ function executeFieldsSerially(exeContext, parentType, sourceValue, path, fields) { return (0, _promiseReduce.default)(Object.keys(fields), function (results, responseName) { var fieldNodes = fields[responseName]; var fieldPath = (0, _Path.addPath)(path, responseName); var result = resolveField(exeContext, parentType, sourceValue, fieldNodes, fieldPath); if (result === undefined) { return results; } if ((0, _isPromise.default)(result)) { return result.then(function (resolvedResult) { results[responseName] = resolvedResult; return results; }); } results[responseName] = result; return results; }, Object.create(null)); } /** * Implements the "Evaluating selection sets" section of the spec * for "read" mode. */ function executeFields(exeContext, parentType, sourceValue, path, fields) { var results = Object.create(null); var containsPromise = false; for (var _i4 = 0, _Object$keys2 = Object.keys(fields); _i4 < _Object$keys2.length; _i4++) { var responseName = _Object$keys2[_i4]; var fieldNodes = fields[responseName]; var fieldPath = (0, _Path.addPath)(path, responseName); var result = resolveField(exeContext, parentType, sourceValue, fieldNodes, fieldPath); if (result !== undefined) { results[responseName] = result; if (!containsPromise && (0, _isPromise.default)(result)) { containsPromise = true; } } } // If there are no promises, we can just return the object if (!containsPromise) { return results; } // Otherwise, results is a map from field name to the result of resolving that // field, which is possibly a promise. Return a promise that will return this // same map, but with any promises replaced with the values they resolved to. return (0, _promiseForObject.default)(results); } /** * Given a selectionSet, adds all of the fields in that selection to * the passed in map of fields, and returns it at the end. * * CollectFields requires the "runtime type" of an object. For a field which * returns an Interface or Union type, the "runtime type" will be the actual * Object type returned by that field. */ function collectFields(exeContext, runtimeType, selectionSet, fields, visitedFragmentNames) { for (var _i6 = 0, _selectionSet$selecti2 = selectionSet.selections; _i6 < _selectionSet$selecti2.length; _i6++) { var selection = _selectionSet$selecti2[_i6]; switch (selection.kind) { case _kinds.Kind.FIELD: { if (!shouldIncludeNode(exeContext, selection)) { continue; } var name = getFieldEntryKey(selection); if (!fields[name]) { fields[name] = []; } fields[name].push(selection); break; } case _kinds.Kind.INLINE_FRAGMENT: { if (!shouldIncludeNode(exeContext, selection) || !doesFragmentConditionMatch(exeContext, selection, runtimeType)) { continue; } collectFields(exeContext, runtimeType, selection.selectionSet, fields, visitedFragmentNames); break; } case _kinds.Kind.FRAGMENT_SPREAD: { var fragName = selection.name.value; if (visitedFragmentNames[fragName] || !shouldIncludeNode(exeContext, selection)) { continue; } visitedFragmentNames[fragName] = true; var fragment = exeContext.fragments[fragName]; if (!fragment || !doesFragmentConditionMatch(exeContext, fragment, runtimeType)) { continue; } collectFields(exeContext, runtimeType, fragment.selectionSet, fields, visitedFragmentNames); break; } } } return fields; } /** * Determines if a field should be included based on the @include and @skip * directives, where @skip has higher precedence than @include. */ function shouldIncludeNode(exeContext, node) { var skip = (0, _values.getDirectiveValues)(_directives.GraphQLSkipDirective, node, exeContext.variableValues); if (skip && skip.if === true) { return false; } var include = (0, _values.getDirectiveValues)(_directives.GraphQLIncludeDirective, node, exeContext.variableValues); if (include && include.if === false) { return false; } return true; } /** * Determines if a fragment is applicable to the given type. */ function doesFragmentConditionMatch(exeContext, fragment, type) { var typeConditionNode = fragment.typeCondition; if (!typeConditionNode) { return true; } var conditionalType = (0, _typeFromAST.typeFromAST)(exeContext.schema, typeConditionNode); if (conditionalType === type) { return true; } if ((0, _definition.isAbstractType)(conditionalType)) { return exeContext.schema.isPossibleType(conditionalType, type); } return false; } /** * Implements the logic to compute the key of a given field's entry */ function getFieldEntryKey(node) { return node.alias ? node.alias.value : node.name.value; } /** * Resolves the field on the given source object. In particular, this * figures out the value that the field returns by calling its resolve function, * then calls completeValue to complete promises, serialize scalars, or execute * the sub-selection-set for objects. */ function resolveField(exeContext, parentType, source, fieldNodes, path) { var fieldNode = fieldNodes[0]; var fieldName = fieldNode.name.value; var fieldDef = getFieldDef(exeContext.schema, parentType, fieldName); if (!fieldDef) { return; } var resolveFn = fieldDef.resolve || exeContext.fieldResolver; var info = buildResolveInfo(exeContext, fieldDef, fieldNodes, parentType, path); // Get the resolve function, regardless of if its result is normal // or abrupt (error). var result = resolveFieldValueOrError(exeContext, fieldDef, fieldNodes, resolveFn, source, info); return completeValueCatchingError(exeContext, fieldDef.type, fieldNodes, info, path, result); } function buildResolveInfo(exeContext, fieldDef, fieldNodes, parentType, path) { // The resolve function's optional fourth argument is a collection of // information about the current execution state. return { fieldName: fieldDef.name, fieldNodes: fieldNodes, returnType: fieldDef.type, parentType: parentType, path: path, schema: exeContext.schema, fragments: exeContext.fragments, rootValue: exeContext.rootValue, operation: exeContext.operation, variableValues: exeContext.variableValues }; } // Isolates the "ReturnOrAbrupt" behavior to not de-opt the `resolveField` // function. Returns the result of resolveFn or the abrupt-return Error object. function resolveFieldValueOrError(exeContext, fieldDef, fieldNodes, resolveFn, source, info) { try { // Build a JS object of arguments from the field.arguments AST, using the // variables scope to fulfill any variable references. // TODO: find a way to memoize, in case this field is within a List type. var args = (0, _values.getArgumentValues)(fieldDef, fieldNodes[0], exeContext.variableValues); // The resolve function's optional third argument is a context value that // is provided to every resolve function within an execution. It is commonly // used to represent an authenticated user, or request-specific caches. var _contextValue = exeContext.contextValue; var result = resolveFn(source, args, _contextValue, info); return (0, _isPromise.default)(result) ? result.then(undefined, asErrorInstance) : result; } catch (error) { return asErrorInstance(error); } } // Sometimes a non-error is thrown, wrap it as an Error instance to ensure a // consistent Error interface. function asErrorInstance(error) { if (error instanceof Error) { return error; } return new Error('Unexpected error value: ' + (0, _inspect.default)(error)); } // This is a small wrapper around completeValue which detects and logs errors // in the execution context. function completeValueCatchingError(exeContext, returnType, fieldNodes, info, path, result) { try { var completed; if ((0, _isPromise.default)(result)) { completed = result.then(function (resolved) { return completeValue(exeContext, returnType, fieldNodes, info, path, resolved); }); } else { completed = completeValue(exeContext, returnType, fieldNodes, info, path, result); } if ((0, _isPromise.default)(completed)) { // Note: we don't rely on a `catch` method, but we do expect "thenable" // to take a second callback for the error case. return completed.then(undefined, function (error) { return handleFieldError(error, fieldNodes, path, returnType, exeContext); }); } return completed; } catch (error) { return handleFieldError(error, fieldNodes, path, returnType, exeContext); } } function handleFieldError(rawError, fieldNodes, path, returnType, exeContext) { var error = (0, _locatedError.locatedError)(asErrorInstance(rawError), fieldNodes, (0, _Path.pathToArray)(path)); // If the field type is non-nullable, then it is resolved without any // protection from errors, however it still properly locates the error. if ((0, _definition.isNonNullType)(returnType)) { throw error; } // Otherwise, error protection is applied, logging the error and resolving // a null value for this field if one is encountered. exeContext.errors.push(error); return null; } /** * Implements the instructions for completeValue as defined in the * "Field entries" section of the spec. * * If the field type is Non-Null, then this recursively completes the value * for the inner type. It throws a field error if that completion returns null, * as per the "Nullability" section of the spec. * * If the field type is a List, then this recursively completes the value * for the inner type on each item in the list. * * If the field type is a Scalar or Enum, ensures the completed value is a legal * value of the type by calling the `serialize` method of GraphQL type * definition. * * If the field is an abstract type, determine the runtime type of the value * and then complete based on that type * * Otherwise, the field type expects a sub-selection set, and will complete the * value by evaluating all sub-selections. */ function completeValue(exeContext, returnType, fieldNodes, info, path, result) { // If result is an Error, throw a located error. if (result instanceof Error) { throw result; } // If field type is NonNull, complete for inner type, and throw field error // if result is null. if ((0, _definition.isNonNullType)(returnType)) { var completed = completeValue(exeContext, returnType.ofType, fieldNodes, info, path, result); if (completed === null) { throw new Error("Cannot return null for non-nullable field ".concat(info.parentType.name, ".").concat(info.fieldName, ".")); } return completed; } // If result value is null-ish (null, undefined, or NaN) then return null. if ((0, _isNullish.default)(result)) { return null; } // If field type is List, complete each item in the list with the inner type if ((0, _definition.isListType)(returnType)) { return completeListValue(exeContext, returnType, fieldNodes, info, path, result); } // If field type is a leaf type, Scalar or Enum, serialize to a valid value, // returning null if serialization is not possible. if ((0, _definition.isLeafType)(returnType)) { return completeLeafValue(returnType, result); } // If field type is an abstract type, Interface or Union, determine the // runtime Object type and complete for that type. if ((0, _definition.isAbstractType)(returnType)) { return completeAbstractValue(exeContext, returnType, fieldNodes, info, path, result); } // If field type is Object, execute and complete all sub-selections. /* istanbul ignore else */ if ((0, _definition.isObjectType)(returnType)) { return completeObjectValue(exeContext, returnType, fieldNodes, info, path, result); } // Not reachable. All possible output types have been considered. /* istanbul ignore next */ (0, _invariant.default)(false, 'Cannot complete value of unexpected output type: ' + (0, _inspect.default)(returnType)); } /** * Complete a list value by completing each item in the list with the * inner type */ function completeListValue(exeContext, returnType, fieldNodes, info, path, result) { if (!(0, _iterall.isCollection)(result)) { throw new _GraphQLError.GraphQLError("Expected Iterable, but did not find one for field ".concat(info.parentType.name, ".").concat(info.fieldName, ".")); } // This is specified as a simple map, however we're optimizing the path // where the list contains no Promises by avoiding creating another Promise. var itemType = returnType.ofType; var containsPromise = false; var completedResults = []; (0, _iterall.forEach)(result, function (item, index) { // No need to modify the info object containing the path, // since from here on it is not ever accessed by resolver functions. var fieldPath = (0, _Path.addPath)(path, index); var completedItem = completeValueCatchingError(exeContext, itemType, fieldNodes, info, fieldPath, item); if (!containsPromise && (0, _isPromise.default)(completedItem)) { containsPromise = true; } completedResults.push(completedItem); }); return containsPromise ? Promise.all(completedResults) : completedResults; } /** * Complete a Scalar or Enum by serializing to a valid value, returning * null if serialization is not possible. */ function completeLeafValue(returnType, result) { var serializedResult = returnType.serialize(result); if ((0, _isInvalid.default)(serializedResult)) { throw new Error("Expected a value of type \"".concat((0, _inspect.default)(returnType), "\" but ") + "received: ".concat((0, _inspect.default)(result))); } return serializedResult; } /** * Complete a value of an abstract type by determining the runtime object type * of that value, then complete the value for that type. */ function completeAbstractValue(exeContext, returnType, fieldNodes, info, path, result) { var resolveTypeFn = returnType.resolveType || exeContext.typeResolver; var contextValue = exeContext.contextValue; var runtimeType = resolveTypeFn(result, contextValue, info, returnType); if ((0, _isPromise.default)(runtimeType)) { return runtimeType.then(function (resolvedRuntimeType) { return completeObjectValue(exeContext, ensureValidRuntimeType(resolvedRuntimeType, exeContext, returnType, fieldNodes, info, result), fieldNodes, info, path, result); }); } return completeObjectValue(exeContext, ensureValidRuntimeType(runtimeType, exeContext, returnType, fieldNodes, info, result), fieldNodes, info, path, result); } function ensureValidRuntimeType(runtimeTypeOrName, exeContext, returnType, fieldNodes, info, result) { var runtimeType = typeof runtimeTypeOrName === 'string' ? exeContext.schema.getType(runtimeTypeOrName) : runtimeTypeOrName; if (!(0, _definition.isObjectType)(runtimeType)) { throw new _GraphQLError.GraphQLError("Abstract type ".concat(returnType.name, " must resolve to an Object type at runtime for field ").concat(info.parentType.name, ".").concat(info.fieldName, " with ") + "value ".concat((0, _inspect.default)(result), ", received \"").concat((0, _inspect.default)(runtimeType), "\". ") + "Either the ".concat(returnType.name, " type should provide a \"resolveType\" function or each possible type should provide an \"isTypeOf\" function."), fieldNodes); } if (!exeContext.schema.isPossibleType(returnType, runtimeType)) { throw new _GraphQLError.GraphQLError("Runtime Object type \"".concat(runtimeType.name, "\" is not a possible type for \"").concat(returnType.name, "\"."), fieldNodes); } return runtimeType; } /** * Complete an Object value by executing all sub-selections. */ function completeObjectValue(exeContext, returnType, fieldNodes, info, path, result) { // If there is an isTypeOf predicate function, call it with the // current result. If isTypeOf returns false, then raise an error rather // than continuing execution. if (returnType.isTypeOf) { var isTypeOf = returnType.isTypeOf(result, exeContext.contextValue, info); if ((0, _isPromise.default)(isTypeOf)) { return isTypeOf.then(function (resolvedIsTypeOf) { if (!resolvedIsTypeOf) { throw invalidReturnTypeError(returnType, result, fieldNodes); } return collectAndExecuteSubfields(exeContext, returnType, fieldNodes, path, result); }); } if (!isTypeOf) { throw invalidReturnTypeError(returnType, result, fieldNodes); } } return collectAndExecuteSubfields(exeContext, returnType, fieldNodes, path, result); } function invalidReturnTypeError(returnType, result, fieldNodes) { return new _GraphQLError.GraphQLError("Expected value of type \"".concat(returnType.name, "\" but got: ").concat((0, _inspect.default)(result), "."), fieldNodes); } function collectAndExecuteSubfields(exeContext, returnType, fieldNodes, path, result) { // Collect sub-fields to execute to complete this value. var subFieldNodes = collectSubfields(exeContext, returnType, fieldNodes); return executeFields(exeContext, returnType, result, path, subFieldNodes); } /** * A memoized collection of relevant subfields with regard to the return * type. Memoizing ensures the subfields are not repeatedly calculated, which * saves overhead when resolving lists of values. */ var collectSubfields = (0, _memoize.default)(_collectSubfields); function _collectSubfields(exeContext, returnType, fieldNodes) { var subFieldNodes = Object.create(null); var visitedFragmentNames = Object.create(null); for (var _i8 = 0; _i8 < fieldNodes.length; _i8++) { var node = fieldNodes[_i8]; if (node.selectionSet) { subFieldNodes = collectFields(exeContext, returnType, node.selectionSet, subFieldNodes, visitedFragmentNames); } } return subFieldNodes; } /** * If a resolveType function is not given, then a default resolve behavior is * used which attempts two strategies: * * First, See if the provided value has a `__typename` field defined, if so, use * that value as name of the resolved type. * * Otherwise, test each possible type for the abstract type by calling * isTypeOf for the object being coerced, returning the first type that matches. */ var defaultTypeResolver = function defaultTypeResolver(value, contextValue, info, abstractType) { // First, look for `__typename`. if ((0, _isObjectLike.default)(value) && typeof value.__typename === 'string') { return value.__typename; } // Otherwise, test each possible type. var possibleTypes = info.schema.getPossibleTypes(abstractType); var promisedIsTypeOfResults = []; for (var i = 0; i < possibleTypes.length; i++) { var type = possibleTypes[i]; if (type.isTypeOf) { var isTypeOfResult = type.isTypeOf(value, contextValue, info); if ((0, _isPromise.default)(isTypeOfResult)) { promisedIsTypeOfResults[i] = isTypeOfResult; } else if (isTypeOfResult) { return type; } } } if (promisedIsTypeOfResults.length) { return Promise.all(promisedIsTypeOfResults).then(function (isTypeOfResults) { for (var _i9 = 0; _i9 < isTypeOfResults.length; _i9++) { if (isTypeOfResults[_i9]) { return possibleTypes[_i9]; } } }); } }; /** * If a resolve function is not given, then a default resolve behavior is used * which takes the property of the source object of the same name as the field * and returns it as the result, or if it's a function, returns the result * of calling that function while passing along args and context value. */ exports.defaultTypeResolver = defaultTypeResolver; var defaultFieldResolver = function defaultFieldResolver(source, args, contextValue, info) { // ensure source is a value for which property access is acceptable. if ((0, _isObjectLike.default)(source) || typeof source === 'function') { var property = source[info.fieldName]; if (typeof property === 'function') { return source[info.fieldName](args, contextValue, info); } return property; } }; /** * This method looks up the field on the given type definition. * It has special casing for the two introspection fields, __schema * and __typename. __typename is special because it can always be * queried as a field, even in situations where no other fields * are allowed, like on a Union. __schema could get automatically * added to the query type, but that would require mutating type * definitions, which would cause issues. */ exports.defaultFieldResolver = defaultFieldResolver; function getFieldDef(schema, parentType, fieldName) { if (fieldName === _introspection.SchemaMetaFieldDef.name && schema.getQueryType() === parentType) { return _introspection.SchemaMetaFieldDef; } else if (fieldName === _introspection.TypeMetaFieldDef.name && schema.getQueryType() === parentType) { return _introspection.TypeMetaFieldDef; } else if (fieldName === _introspection.TypeNameMetaFieldDef.name) { return _introspection.TypeNameMetaFieldDef; } return parentType.getFields()[fieldName]; }