test: adds diagnostic outputs for E2E in feature flags

Author: christopherferreira9

app/core/Engine/controllers/remote-feature-flag-controller-init.ts

@@ -14,6 +14,33 @@ import {
   isRemoteFeatureFlagOverrideActivated,
 } from './remote-feature-flag-controller';
 import { getBaseSemVerVersion } from '../../../util/version';
+import {
+  getE2ERemoteFeatureFlagDiagnostics,
+  isE2E,
+  postE2EDiagnostics,
+} from '../../../util/test/utils';
+
+const getDiagnosticErrorMessage = (error: unknown) =>
+  error instanceof Error ? error.message : String(error);
+
+const postRemoteFeatureFlagDiagnostics = (
+  controller: RemoteFeatureFlagController,
+  phase: string,
+  error?: unknown,
+) => {
+  if (!isE2E) {
+    return;
+  }
+
+  postE2EDiagnostics(
+    getE2ERemoteFeatureFlagDiagnostics(controller.state, {
+      phase,
+      ...(error === undefined
+        ? {}
+        : { error: getDiagnosticErrorMessage(error) }),
+    }),
+  );
+};
 
 /**
  * Initialize the remote feature flag controller.
@@ -52,15 +79,21 @@ export const remoteFeatureFlagControllerInit: MessengerClientInitFunction<
 
   if (disabled) {
     Logger.log('Feature flag controller disabled.');
+    postRemoteFeatureFlagDiagnostics(controller, 'disabled');
   } else if (isRemoteFeatureFlagOverrideActivated) {
     Logger.log('Remote feature flags override activated.');
+    postRemoteFeatureFlagDiagnostics(controller, 'override-activated');
   } else {
     controller
       .updateRemoteFeatureFlags()
       .then(() => {
         Logger.log('Feature flags updated');
+        postRemoteFeatureFlagDiagnostics(controller, 'update-success');
       })
-      .catch((error) => Logger.log('Feature flags update failed: ', error));
+      .catch((error) => {
+        Logger.log('Feature flags update failed: ', error);
+        postRemoteFeatureFlagDiagnostics(controller, 'update-failed', error);
+      });
   }
 
   return {

app/util/test/utils.js

@@ -84,6 +84,64 @@ export const getE2ETestConfigDiagnostics = (extra = {}) => ({
   ...extra,
 });
 
+const getObjectValue = (value, key) => {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    return undefined;
+  }
+
+  return value[key];
+};
+
+const getObjectKeysDiagnostic = (value) => {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    return 'missing';
+  }
+
+  const keys = Object.keys(value).sort();
+  return keys.length > 0 ? keys.join(',') : 'none';
+};
+
+export const getE2ERemoteFeatureFlagDiagnostics = (state = {}, extra = {}) => {
+  const remoteFeatureFlags = getObjectValue(state, 'remoteFeatureFlags');
+  const rawRemoteFeatureFlags = getObjectValue(state, 'rawRemoteFeatureFlags');
+  const localOverrides = getObjectValue(state, 'localOverrides');
+
+  return {
+    source: extra.source ?? 'RemoteFeatureFlagController',
+    phase: extra.phase ?? 'unknown',
+    explorePageV2EnabledInApp: formatE2EDiagnosticValue(
+      getObjectValue(remoteFeatureFlags, 'explorePageV2Enabled'),
+    ),
+    explorePageV2EnabledRaw: formatE2EDiagnosticValue(
+      getObjectValue(rawRemoteFeatureFlags, 'explorePageV2Enabled'),
+    ),
+    explorePageV2EnabledOverride: formatE2EDiagnosticValue(
+      getObjectValue(localOverrides, 'explorePageV2Enabled'),
+    ),
+    remoteFeatureFlagsCacheTimestamp: formatE2EDiagnosticValue(
+      getObjectValue(state, 'cacheTimestamp'),
+    ),
+    remoteFeatureFlagsKeys: getObjectKeysDiagnostic(remoteFeatureFlags),
+    rawRemoteFeatureFlagsKeys: getObjectKeysDiagnostic(rawRemoteFeatureFlags),
+    localOverridesKeys: getObjectKeysDiagnostic(localOverrides),
+    ...extra,
+  };
+};
+
+export const postE2EDiagnostics = async (diagnostics) => {
+  const postDiagnostics = testConfig.postE2EDiagnostics;
+
+  if (typeof postDiagnostics !== 'function') {
+    return;
+  }
+
+  try {
+    await postDiagnostics(diagnostics);
+  } catch {
+    // Diagnostics must never affect app startup or test behavior.
+  }
+};
+
 export const appendE2EDiagnosticsToUrl = (url, diagnostics) => {
   const nextUrl = new URL(url);
   Object.entries(diagnostics).forEach(([key, value]) => {