Regression test for abstract root fragment

Differential Revision: D80984351

Author: captbaritone

packages/react-relay/__tests__/RelayResolvers-abstractTypeRootFragment-test.js

@@ -0,0 +1,100 @@
+/**
+ * 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
+ * @oncall relay
+ */
+
+'use strict';
+
+import type {IEnvironment} from 'relay-runtime';
+
+const React = require('react');
+const {RelayEnvironmentProvider, useLazyLoadQuery} = require('react-relay');
+const TestRenderer = require('react-test-renderer');
+const {graphql} = require('relay-runtime/query/GraphQLTag');
+const {createMockEnvironment} = require('relay-test-utils');
+const {
+  disallowConsoleErrors,
+  disallowWarnings,
+} = require('relay-test-utils-internal');
+
+disallowWarnings();
+disallowConsoleErrors();
+
+function EnvironmentWrapper({
+  children,
+  environment,
+}: {
+  children: React.Node,
+  environment: IEnvironment,
+}) {
+  return (
+    <RelayEnvironmentProvider environment={environment}>
+      <React.Suspense fallback="Loading...">{children}</React.Suspense>
+    </RelayEnvironmentProvider>
+  );
+}
+
+function NodeGreeting() {
+  const data = useLazyLoadQuery(
+    graphql`
+      query RelayResolversAbstractTypeRootFragmentTestQuery {
+        node(id: "4") {
+          node_greeting
+        }
+      }
+    `,
+    {},
+  );
+  return data.node?.node_greeting;
+}
+
+// https://github.com/facebook/relay/issues/4943#issuecomment-3221637018
+test('Can read a resolver with a rootFragment on an abstract type', async () => {
+  const logEvents = [];
+  const environment = createMockEnvironment({
+    relayFieldLogger(event) {
+      logEvents.push(event);
+    },
+  });
+  let renderer;
+  TestRenderer.act(() => {
+    renderer = TestRenderer.create(
+      <EnvironmentWrapper environment={environment}>
+        <NodeGreeting />
+      </EnvironmentWrapper>,
+    );
+  });
+  expect(renderer?.toJSON()).toEqual('Loading...');
+  expect(logEvents).toEqual([]);
+
+  await TestRenderer.act(() => {
+    environment.mock.resolveMostRecentOperation({
+      data: {
+        node: {
+          __typename: 'User',
+          __isNode: 'User',
+          id: '4',
+        },
+      },
+    });
+    jest.runAllImmediates();
+  });
+
+  // Incorrect! We provided `__isNode`!
+  expect(logEvents).toEqual([
+    {
+      fieldPath: '<abstract-type-hint>',
+      kind: 'missing_expected_data.log',
+      owner: 'NodeResolversGreeting',
+      uiContext: undefined,
+    },
+  ]);
+  // Incorrect! Should be the greeting.
+  expect(renderer?.toJSON()).toEqual(null);
+});