forked from graphql/graphql-js
/
getOperationAST.js
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/
getOperationAST.js
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/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow strict
*/
import { Kind } from '../language/kinds';
import {
type DocumentNode,
type OperationDefinitionNode,
} from '../language/ast';
/**
* Returns an operation AST given a document AST and optionally an operation
* name. If a name is not provided, an operation is only returned if only one is
* provided in the document.
*/
export function getOperationAST(
documentAST: DocumentNode,
operationName: ?string,
): ?OperationDefinitionNode {
let operation = null;
for (const definition of documentAST.definitions) {
if (definition.kind === Kind.OPERATION_DEFINITION) {
if (!operationName) {
// If no operation name was provided, only return an Operation if there
// is one defined in the document. Upon encountering the second, return
// null.
if (operation) {
return null;
}
operation = definition;
} else if (definition.name && definition.name.value === operationName) {
return definition;
}
}
}
return operation;
}