// @flow strictimport flatMap from '../polyfills/flatMap';import { type DocumentNode } from '../language/ast';/** * Provided a collection of ASTs, presumably each from different files, * concatenate the ASTs together into batched AST, useful for validating many * GraphQL source files which together represent one conceptual application. */export function concatAST(asts: $ReadOnlyArray<DocumentNode>): DocumentNode { return { kind: 'Document', definitions: flatMap(asts, ast => ast.definitions), };}