DefinitelyTyped · alina-zaieva · Nov 6, 2025 · Nov 7, 2025 · Nov 7, 2025 · Nov 12, 2025
@@ -1,3 +1,27 @@
+import { DataID } from "./lib/util/RelayRuntimeTypes";
+
+export { resolverDataInjector } from "./lib/store/live-resolvers/resolverDataInjector";
 export { observeFragment } from "./lib/store/observeFragmentExperimental";
 export { observeQuery } from "./lib/store/observeQueryExperimental";
 export { waitForFragmentData } from "./lib/store/waitForFragmentExperimental";
+
+export type IdOf<_A extends string, Typename extends undefined | string = undefined> = Typename extends undefined
+    ? { id: DataID }
+    : { id: DataID; __typename: Typename };
+
+interface ErrorResult<E> {
+    ok: false;
+    errors: readonly E[];
+}
+
+interface OkayResult<T> {
+    ok: true;
+    value: T;
+}
+
+// The type returned by fields annotated with `@catch`
+export type Result<T, E> = OkayResult<T> | ErrorResult<E>;
+
+export function isValueResult<T = unknown>(input: Result<T, unknown>): input is OkayResult<T>;
+
+export function isErrorResult<E = unknown>(input: Result<unknown, E>): input is ErrorResult<E>;
@@ -154,6 +154,7 @@ export { RelayModernRecord as Record } from "./lib/store/RelayModernRecord";
 export { default as Store } from "./lib/store/RelayModernStore";
 export { RelayRecordSource as RecordSource } from "./lib/store/RelayRecordSource";
 
+export { type IdOf, isErrorResult, isValueResult, type Result } from "./experimental";
 export { createFragmentSpecResolver } from "./lib/store/createFragmentSpecResolver";
 export { readInlineData } from "./lib/store/readInlineData";
 export { createOperationDescriptor, createRequestDescriptor } from "./lib/store/RelayModernOperationDescriptor";
@@ -185,6 +186,7 @@ export {
     ROOT_TYPE,
     TYPENAME_KEY,
 } from "./lib/store/RelayStoreUtils";
+export { readFragment } from "./lib/store/ResolverFragments";
 
 // Extensions
 import RelayDefaultHandlerProvider from "./lib/handlers/RelayDefaultHandlerProvider";
@@ -267,16 +269,3 @@ export type FragmentRefs<Refs extends string> = {
 
 // This is a utility type for converting from a data type to a fragment reference that will resolve to that data type.
 export type FragmentRef<Fragment> = Fragment extends _RefType<infer U> ? _FragmentRefs<U> : never;
-
-interface ErrorResult<Error> {
-    ok: false;
-    errors: readonly Error[];
-}
-
-interface OkayResult<T> {
-    ok: true;
-    value: T;
-}
-
-// The type returned by fields annotated with `@catch`
-export type Result<T, Error> = OkayResult<T> | ErrorResult<Error>;
@@ -0,0 +1,20 @@
+import type { GraphQLTaggedNode } from "../../query/RelayModernGraphQLTag";
+import type { FragmentType } from "../RelayStoreTypes";
+
+/**
+ * This a higher order function that returns a relay resolver that can read the data for
+ * the fragment`.
+ *
+ * - fragment: contains fragment Reader AST with resolver's data dependencies.
+ * - resolverFn: original resolver function that expects a data from the fragment
+ * - (optional) fieldName: individual field that needs to be read out of the fragment.
+ *
+ * This will not call the `resolverFn` if the fragment data for it is null/undefined.
+ * The compiler generates calls to this function, ensuring the correct set of arguments.
+ */
+export function resolverDataInjector(
+    fragment: GraphQLTaggedNode,
+    _resolverFn: unknown,
+    fieldName?: string,
+    isRequiredField?: boolean,
+): (fragmentKey: FragmentType, args: unknown) => unknown;
@@ -1,7 +1,7 @@
 {
     "private": true,
     "name": "@types/relay-runtime",
-    "version": "19.0.9999",
+    "version": "20.1.9999",
     "projects": [
         "https://github.com/facebook/relay",
         "https://facebook.github.io/relay"

@@ -15,14 +15,17 @@ import {
     getRefetchMetadata,
     getRequest,
     graphql,
+    isErrorResult,
     isPromise,
+    isValueResult,
     LiveState,
     Network,
     PreloadableConcreteRequest,
     PreloadableQueryRegistry,
     QueryResponseCache,
     ReaderFragment,
     ReaderInlineDataFragment,
+    readFragment,
     readInlineData,
     RecordProxy,
     RecordSource,
@@ -35,7 +38,13 @@ import {
     suspenseSentinel,
     Variables,
 } from "relay-runtime";
-import { observeFragment, observeQuery, waitForFragmentData } from "relay-runtime/experimental";
+import {
+    IdOf,
+    observeFragment,
+    observeQuery,
+    resolverDataInjector,
+    waitForFragmentData,
+} from "relay-runtime/experimental";
 
 import type { HandlerProvider } from "relay-runtime/lib/handlers/RelayDefaultHandlerProvider";
 import * as multiActorEnvironment from "relay-runtime/multi-actor-environment";
@@ -701,8 +710,6 @@ function multiActors() {
 // Relay Resolvers
 // ~~~~~~~~~~~~~~~~~~~~~~~
 
-const { readFragment } = __internal.ResolverFragments;
-
 // Regular fragment.
 interface UserComponent_user {
     readonly id: string;
@@ -921,6 +928,20 @@ export function handleResult<T, E>(result: Result<T, E>) {
     }
 }
 
+// eslint-disable-next-line @definitelytyped/no-unnecessary-generics
+export function handleValueResult<T, E>(result: Result<T, E>) {
+    if (isValueResult(result)) {
+        const value: T = result.value;
+    }
+}
+
+// eslint-disable-next-line @definitelytyped/no-unnecessary-generics
+export function handleErrorResult<T, E>(result: Result<T, E>) {
+    if (isErrorResult(result)) {
+        const errors: readonly E[] = result.errors;
+    }
+}
+
 // ~~~~~~~~~~~~~~~~~~
 // Metadata
 // ~~~~~~~~~~~~~~~~~~
@@ -1048,3 +1069,61 @@ function observeQueryTest() {
 
     subscription.unsubscribe();
 }
+
+// ~~~~~~~~~~~~~~~~~~
+// resolverDataInjector
+// ~~~~~~~~~~~~~~~~~~
+
+const MyResolverType__id_graphql: ReaderFragment = {
+    "argumentDefinitions": [],
+    "kind": "Fragment",
+    "metadata": null,
+    "name": "MyResolverType__id",
+    "selections": [
+        {
+            "kind": "ClientExtension",
+            "selections": [
+                {
+                    "alias": null,
+                    "args": null,
+                    "kind": "ScalarField",
+                    "name": "id",
+                    "storageKey": null,
+                },
+            ],
+        },
+    ],
+    "type": "MyResolverType",
+    "abstractKey": null,
+};
+
+interface MyResolverType {
+    id: string;
+}
+
+function myResolverTypeRelayModelInstanceResolver(id: DataID): MyResolverType {
+    return {
+        id,
+    };
+}
+
+export const resolverModule = resolverDataInjector(
+    MyResolverType__id_graphql,
+    myResolverTypeRelayModelInstanceResolver,
+    "id",
+    true,
+);
+
+// ~~~~~~~~~~~~~~~~~~
+// Client edge resolver
+// ~~~~~~~~~~~~~~~~~~
+
+export function myDog(): IdOf<"Dog"> {
+    return { id: "5" };
+}
+
+type AnimalTypenames = "Cat" | "Dog";
+
+export function myAnimal(): IdOf<"Animal", AnimalTypenames> {
+    return Math.random() > 0.5 ? { id: "5", __typename: "Dog" } : { id: "6", __typename: "Cat" };
+}