From 2325e4bf48fb4621029ab5afd5a827ce138923ea Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 12 Mar 2026 14:38:12 +0100
Subject: [PATCH] frontend-app-api: integrate predicate context into app phases

Compute and cache extension predicate context as part of app phase transitions so sign-in and non-sign-in flows finalize against the same gating state.

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor
---
 .../src/wiring/createSpecializedApp.test.tsx  | 80 +++++++++++++++++++
 .../frontend-defaults/src/createApp.test.tsx  | 50 ++++++++++++
 packages/frontend-defaults/src/createApp.tsx  | 27 ++-----
 3 files changed, 138 insertions(+), 19 deletions(-)

diff --git a/packages/frontend-app-api/src/wiring/createSpecializedApp.test.tsx b/packages/frontend-app-api/src/wiring/createSpecializedApp.test.tsx
index cd1356d4cb..1695897a14 100644
--- a/packages/frontend-app-api/src/wiring/createSpecializedApp.test.tsx
+++ b/packages/frontend-app-api/src/wiring/createSpecializedApp.test.tsx
@@ -1731,6 +1731,86 @@ describe('createSpecializedApp', () => {
       );
     });
 
+    it('should reuse predicate context gathered during sign-in completion', async () => {
+      const identityApi = {
+        getProfileInfo: async () => ({ displayName: 'Test User' }),
+        getBackstageIdentity: async () => ({
+          type: 'user' as const,
+          userEntityRef: 'user:default/test-user',
+          ownershipEntityRefs: ['user:default/test-user'],
+        }),
+        getCredentials: async () => ({ token: 'token' }),
+        signOut: async () => {},
+      };
+      const featureFlagsApi = {
+        isActive: jest.fn((name: string) => name === 'test-flag'),
+        registerFlag: jest.fn(),
+        getRegisteredFlags: () => [],
+        save: jest.fn(),
+      } as unknown as typeof featureFlagsApiRef.T;
+      const gatedAppPlugin = appPluginOriginal.withOverrides({
+        extensions: [
+          appPluginOriginal.getExtension('app/layout').override({
+            if: { featureFlags: { $contains: 'test-flag' } },
+            factory: () => [
+              coreExtensionData.reactElement(<div>Flagged Layout</div>),
+            ],
+          }),
+        ],
+      });
+
+      const preparedApp = prepareSpecializedApp({
+        features: [
+          gatedAppPlugin,
+          createFrontendModule({
+            pluginId: 'app',
+            extensions: [
+              ApiBlueprint.make({
+                params: defineParams =>
+                  defineParams({
+                    api: featureFlagsApiRef,
+                    deps: {},
+                    factory: () => featureFlagsApi,
+                  }),
+              }),
+              gatedAppPlugin.getExtension('sign-in-page:app').override({
+                factory: () => {
+                  function SignInPage(props: {
+                    onSignInSuccess(identity: IdentityApi): void;
+                  }) {
+                    useEffect(() => {
+                      props.onSignInSuccess(identityApi);
+                    }, [props]);
+                    return <div>Custom Sign In</div>;
+                  }
+
+                  return [signInPageComponentDataRef(SignInPage)];
+                },
+              }),
+            ],
+          }),
+        ],
+      });
+
+      const signIn = preparedApp.getSignIn();
+      render(signIn!.element);
+      await expect(
+        screen.findByText('Custom Sign In'),
+      ).resolves.toBeInTheDocument();
+
+      await signIn!.complete;
+      expect(featureFlagsApi.isActive).toHaveBeenCalledWith('test-flag');
+
+      const finalizedApp = preparedApp.finalize();
+      render(
+        finalizedApp.tree.root.instance!.getData(
+          coreExtensionData.reactElement,
+        ),
+      );
+
+      expect(screen.getByText('Flagged Layout')).toBeInTheDocument();
+    });
+
     it('should gate finalize behind internal async sign-in finalization', async () => {
       const identityApi = {
         getProfileInfo: async () => ({ displayName: 'Test User' }),
diff --git a/packages/frontend-defaults/src/createApp.test.tsx b/packages/frontend-defaults/src/createApp.test.tsx
index af8517624a..540fb5e41c 100644
--- a/packages/frontend-defaults/src/createApp.test.tsx
+++ b/packages/frontend-defaults/src/createApp.test.tsx
@@ -386,6 +386,56 @@ describe('createApp', () => {
     ).resolves.toBeInTheDocument();
   });
 
+  it('should evaluate extension if predicates before rendering apps without sign-in', async () => {
+    const featureFlagsApi = {
+      isActive: jest.fn((name: string) => name === 'test-flag'),
+      registerFlag: jest.fn(),
+      getRegisteredFlags: () => [],
+      save: jest.fn(),
+    } as unknown as typeof featureFlagsApiRef.T;
+    const app = createApp({
+      advanced: {
+        configLoader: async () => ({ config: mockApis.config() }),
+      },
+      features: [
+        appPlugin,
+        createFrontendModule({
+          pluginId: 'app',
+          extensions: [
+            ApiBlueprint.make({
+              params: defineParams =>
+                defineParams({
+                  api: featureFlagsApiRef,
+                  deps: {},
+                  factory: () => featureFlagsApi,
+                }),
+            }),
+          ],
+        }),
+        createFrontendPlugin({
+          pluginId: 'test',
+          featureFlags: [{ name: 'test-flag' }],
+          extensions: [
+            PageBlueprint.make({
+              if: { featureFlags: { $contains: 'test-flag' } },
+              params: {
+                path: '/',
+                loader: async () => <div>Flagged Page</div>,
+              },
+            }),
+          ],
+        }),
+      ],
+    });
+
+    await renderWithEffects(app.createRoot());
+
+    await expect(
+      screen.findByText('Flagged Page'),
+    ).resolves.toBeInTheDocument();
+    expect(featureFlagsApi.isActive).toHaveBeenCalledWith('test-flag');
+  });
+
   it('should make the app structure available through the AppTreeApi', async () => {
     let appTreeApi: AppTreeApi | undefined = undefined;
 
diff --git a/packages/frontend-defaults/src/createApp.tsx b/packages/frontend-defaults/src/createApp.tsx
index 8a47088f62..50f8db64f7 100644
--- a/packages/frontend-defaults/src/createApp.tsx
+++ b/packages/frontend-defaults/src/createApp.tsx
@@ -133,6 +133,8 @@ export function createApp(options?: CreateAppOptions): {
       };
     }
 
+    await preparedApp.buildPredicateContext();
+
     return {
       default: () => renderFinalizedApp(preparedApp.finalize()),
     };
@@ -164,12 +166,15 @@ function PreparedAppRoot(props: {
     let cancelled = false;
     const runFinalize = async () => {
       try {
-        const predicateContext =
+        if (signIn) {
+          await signIn.complete;
+        } else {
           await props.preparedApp.buildPredicateContext();
+        }
         if (cancelled) {
           return;
         }
-        setFinalizedApp(props.preparedApp.finalize(predicateContext));
+        setFinalizedApp(props.preparedApp.finalize());
       } catch (error) {
         if (cancelled) {
           return;
@@ -177,23 +182,7 @@ function PreparedAppRoot(props: {
         setFinalizeError(error as Error);
       }
     };
-    if (signIn) {
-      void signIn.complete
-        .then(() => {
-          if (cancelled) {
-            return;
-          }
-          void runFinalize();
-        })
-        .catch(error => {
-          if (cancelled) {
-            return;
-          }
-          setFinalizeError(error);
-        });
-    } else {
-      setFinalizedApp(props.preparedApp.finalize());
-    }
+    void runFinalize();
     return () => {
       cancelled = true;
     };