packages/relay-runtime/store/readInlineData.js

/**
 * Copyright (c) Meta Platforms, Inc. and 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-local
 * @format
 */

// flowlint ambiguous-object-type:error

'use strict';

import type {GraphQLTaggedNode} from '../query/GraphQLTag';
import type {FragmentType} from './RelayStoreTypes';

const {getInlineDataFragment} = require('../query/GraphQLTag');
const {FRAGMENTS_KEY} = require('./RelayStoreUtils');
const invariant = require('invariant');

/**
 * Reads an @inline data fragment that was spread into the parent fragment.
 */

declare function readInlineData<
  TFragmentType: FragmentType,
  TData,
  TKey: {
    +$data?: TData,
    +$fragmentSpreads: TFragmentType,
    ...
  },
>(
  fragment: GraphQLTaggedNode,
  fragmentRef: TKey,
): TData;
declare function readInlineData<
  TFragmentType: FragmentType,
  TData,
  TKey: ?{
    +$data?: TData,
    +$fragmentSpreads: TFragmentType,
    ...
  },
>(
  fragment: GraphQLTaggedNode,
  fragmentRef: null | void,
): ?TData;
function readInlineData(
  fragment: GraphQLTaggedNode,
  fragmentRef: mixed,
): mixed {
  const inlineDataFragment = getInlineDataFragment(fragment);
  if (fragmentRef == null) {
    return fragmentRef;
  }
  invariant(
    typeof fragmentRef === 'object',
    'readInlineData(): Expected an object, got `%s`.',
    typeof fragmentRef,
  );
  // $FlowFixMe[incompatible-use]
  const inlineData = fragmentRef[FRAGMENTS_KEY]?.[inlineDataFragment.name];
  invariant(
    inlineData != null,
    'readInlineData(): Expected fragment `%s` to be spread in the parent ' +
      'fragment.',
    inlineDataFragment.name,
  );
  return inlineData;
}

module.exports = readInlineData;