add readInlineData (#38462)

* add readInlineData

* Update index.d.ts

* add tests

* fix

* lint

* add fragment as example

types/react-relay/index.d.ts

@@ -140,6 +140,11 @@ interface ConnectionData {
     pageInfo?: Partial<PageInfo> | null;
 }
 
+export function readInlineData<T extends _RefType<any>>(
+    fragment: GraphQLTaggedNode,
+    ref: FragmentOrRegularProp<T>,
+): T;
+
 type FragmentVariablesGetter = (prevVars: Variables, totalCount: number) => Variables;
 
 export interface ConnectionConfig<Props = object> {

types/react-relay/test/react-relay-tests.tsx

@@ -5,17 +5,19 @@ import * as React from 'react';
 import { Environment, Network, RecordSource, Store, ConnectionHandler } from 'relay-runtime';
 
 import {
-    graphql,
-    commitMutation,
-    createFragmentContainer,
-    createPaginationContainer,
-    createRefetchContainer,
-    requestSubscription,
-    QueryRenderer,
-    ReactRelayContext,
-    RelayRefetchProp,
-    RelayPaginationProp,
-    RelayProp,
+  commitMutation,
+  createFragmentContainer,
+  createPaginationContainer,
+  createRefetchContainer,
+  FragmentOrRegularProp,
+  graphql,
+  QueryRenderer,
+  ReactRelayContext,
+  readInlineData,
+  RelayPaginationProp,
+  RelayProp,
+  RelayRefetchProp,
+  requestSubscription,
 } from 'react-relay';
 
 // ~~~~~~~~~~~~~~~~~~~~~
@@ -594,6 +596,26 @@ function markNotificationAsRead(source: string, storyID: string) {
     });
 }
 
+// ~~~~~~~~~~~~~~~~~~~~~
+// readInlineData
+// ~~~~~~~~~~~~~~~~~~~~~
+
+const storyFragment = graphql`
+    fragment Story_story on Todo {
+        id
+        text
+        isPublished
+    }
+`;
+
+function functionWithInline(
+    storyRef: FragmentOrRegularProp<Story_story>,
+): Story_story {
+    return readInlineData<Story_story>(storyFragment, storyRef);
+}
+
+functionWithInline({ ' $fragmentRefs': _Story_story$ref });
+
 // ~~~~~~~~~~~~~~~~~~~~~
 // Modern Subscriptions
 // ~~~~~~~~~~~~~~~~~~~~~