Add setting for opting in to beta features (#11123)

src/analytics/features/index.ts

@@ -1,8 +1,11 @@
 import {MMKV} from '@bsky.app/react-native-mmkv'
 import {setPolyfills} from '@growthbook/growthbook'
 import {GrowthBook} from '@growthbook/growthbook-react'
+import {type I18n} from '@lingui/core'
+import {msg} from '@lingui/core/macro'
 
 import {Logger} from '#/logger'
+import {Features} from '#/analytics/features/types'
 import {getNavigationMetadata, type Metadata} from '#/analytics/metadata'
 import * as env from '#/env'
 
@@ -11,12 +14,14 @@ export {Features} from '#/analytics/features/types'
 const logger = Logger.create(Logger.Context.Growthbook)
 const CACHE = new MMKV({id: 'bsky_features_cache'})
 
+const BETA_USER_ATTRIBUTE = 'isBetaUser'
+
 setPolyfills({
   localStorage: {
     getItem: key => {
       return CACHE.getString(key) ?? null
     },
-    setItem: async (key, value) => {
+    setItem: (key, value) => {
       CACHE.set(key, value)
     },
   },
@@ -44,15 +49,13 @@ export const features = new GrowthBook({
  * that case, we may see a flash of uncustomized content until the
  * initialization completes.
  */
-export const init = new Promise<void>(async y => {
-  const res = await features.init({timeout: TIMEOUT_INIT})
+export const init = features.init({timeout: TIMEOUT_INIT}).then(res => {
   if (!res.success) {
     logger.warn('GrowthBook initialization failed or timed out', {
       source: res.source,
       safeMessage: res.error?.toString(),
     })
   }
-  y()
 })
 
 /**
@@ -68,6 +71,89 @@ export async function refresh({strategy}: {strategy: FeatureFetchStrategy}) {
   })
 }
 
+export function getFeatures() {
+  return features.getFeatures()
+}
+
+export function getFeatureDescription(feature: Features, i18n: I18n) {
+  switch (feature) {
+    case Features.PostThreadKnownLikersEnable:
+      return {
+        key: feature,
+        name: i18n._(
+          msg({
+            message: 'Social proofing on posts',
+            comment: 'Name for a feature flag',
+          }),
+        ),
+        description: i18n._(
+          msg({
+            message: 'Spot posts your friends and follows have liked.',
+            comment: 'Description of a feature flag (Social proofing on posts)',
+          }),
+        ),
+      }
+    default:
+      return null
+  }
+}
+
+/**
+ * Walks a GrowthBook condition tree to determine whether it targets the given
+ * attribute. Conditions can nest via the logical operators `$and`, `$or`,
+ * `$nor` (arrays of sub-conditions) and `$not` (a single sub-condition), so a
+ * flat scan of the top-level keys would miss e.g.
+ * `{$and: [{isBetaUser: true}, ...]}`. Dot-notation access (e.g.
+ * `isBetaUser.foo`) counts as targeting the attribute as well.
+ */
+function conditionTargetsAttribute(
+  condition: unknown,
+  attribute: string,
+): boolean {
+  if (!condition || typeof condition !== 'object') return false
+
+  for (const [key, value] of Object.entries(condition)) {
+    if (key === attribute || key.startsWith(`${attribute}.`)) return true
+
+    if (key === '$and' || key === '$or' || key === '$nor') {
+      if (
+        Array.isArray(value) &&
+        value.some(sub => conditionTargetsAttribute(sub, attribute))
+      ) {
+        return true
+      }
+    } else if (key === '$not') {
+      if (conditionTargetsAttribute(value, attribute)) return true
+    }
+  }
+
+  return false
+}
+
+export function getTargetedFeatures(i18n: I18n) {
+  const allFeatures = features.getFeatures()
+  const targetedFeatures: {key: Features; name: string; description: string}[] =
+    []
+  for (const [featureKey, feature] of Object.entries(allFeatures)) {
+    // Check if the feature contains any rules
+    if (!feature.rules) continue
+
+    // Determine if any rule targets the beta user attribute
+    const hasTargeting = feature.rules.some(rule =>
+      conditionTargetsAttribute(rule.condition, BETA_USER_ATTRIBUTE),
+    )
+
+    if (hasTargeting) {
+      const featureName = getFeatureDescription(featureKey as Features, i18n)
+      if (featureName) {
+        targetedFeatures.push(featureName)
+      }
+    }
+  }
+
+  return targetedFeatures
+}
+
 /**
  * Converts our metadata into GrowthBook attributes and sets them. GrowthBook
  * attributes are manually configured in the GrowthBook dashboard. So these
@@ -80,7 +166,7 @@ export function setAttributes({
   session,
   preferences,
 }: Metadata) {
-  features.setAttributes({
+  void features.setAttributes({
     deviceId: base.deviceId,
     sessionId: base.sessionId,
     platform: base.platform,
@@ -92,5 +178,6 @@ export function setAttributes({
     appLanguage: preferences?.appLanguage,
     contentLanguages: preferences?.contentLanguages,
     currentScreen: getNavigationMetadata()?.currentScreen,
+    isBetaUser: base.isBetaUser,
   })
 }

src/analytics/features/types.ts

@@ -1,3 +1,7 @@
+/**
+ * If a feature is in the beta program, be sure to add a localized description
+ * for it via getFeatureDescription().
+ */
 export enum Features {
   // core flags
   IsBskyTeam = 'is_bsky_team',

src/analytics/index.tsx

@@ -1,4 +1,10 @@
-import {createContext, useContext, useMemo} from 'react'
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useMemo,
+  useSyncExternalStore,
+} from 'react'
 import {Platform} from 'react-native'
 import {type Result} from '@growthbook/growthbook-react'
 
@@ -26,7 +32,7 @@ import {type Metrics, metrics} from '#/analytics/metrics'
 import * as refParams from '#/analytics/misc/refParams'
 import * as env from '#/env'
 import {useGeolocationServiceResponse} from '#/geolocation/service'
-import {device} from '#/storage'
+import {account, device} from '#/storage'
 
 export * as utils from '#/analytics/utils'
 export const features = {init, refresh}
@@ -120,6 +126,38 @@ Context.displayName = 'AnalyticsContext'
  */
 export const setupDeviceId = getAndMigrateDeviceId()
 
+/**
+ * Reads the per-account cached `isBetaUser` flag for `did`, kept in sync with
+ * writes from `BetaUserStorageSync` and the beta settings toggle.
+ *
+ * This deliberately does not use `useStorage`, whose `useState` seeds once and
+ * only updates via the change listener. The consuming `AnalyticsContext` lives
+ * above the `<Fragment key={did}>` remount breaker, so on an account switch it
+ * re-renders (with a new did) rather than remounting. `useStorage` would keep
+ * serving the previous account's seeded value until a write happened to fire
+ * its listener, leaking a beta account's flag into a non-beta account. Reading
+ * via `useSyncExternalStore` re-evaluates `getSnapshot` every render, so the
+ * value is always correct for the current did.
+ */
+function useAccountIsBetaUser(did: string | undefined): boolean | undefined {
+  const subscribe = useCallback(
+    (onChange: () => void) => {
+      if (!did) return () => {}
+      const sub = account.addOnValueChangedListener(
+        [did, 'isBetaUser'],
+        onChange,
+      )
+      return () => sub.remove()
+    },
+    [did],
+  )
+  const getSnapshot = useCallback(() => {
+    if (!did) return undefined
+    return account.get([did, 'isBetaUser'])
+  }, [did])
+  return useSyncExternalStore(subscribe, getSnapshot)
+}
+
 /**
  * Analytics context provider. Decorates the parent analytics context with
  * additional metadata. Nesting should be done carefully and sparingly.
@@ -141,6 +179,16 @@ export function AnalyticsContext({
   const sessionId = useSessionId()
   const geolocation = useGeolocationServiceResponse()
   const parentContext = useContext(Context)
+  /*
+   * `isBetaUser` is account-specific, so it's cached per account. Read it
+   * scoped to the did for this render's session (from the `metadata` prop when
+   * set, otherwise inherited from the parent context). Without a did (e.g.
+   * logged out, or the top-level context above the session provider) there's
+   * no value, so beta-gated features are never evaluated for an ineligible or
+   * absent account.
+   */
+  const did = metadata?.session?.did ?? parentContext.metadata.session?.did
+  const isBetaUser = useAccountIsBetaUser(did)
   const childContext = useMemo(() => {
     const combinedMetadata = {
       ...parentContext.metadata,
@@ -148,6 +196,7 @@ export function AnalyticsContext({
       base: {
         ...parentContext.metadata.base,
         sessionId,
+        isBetaUser,
       },
       geolocation,
     }
@@ -166,7 +215,7 @@ export function AnalyticsContext({
       },
     }
     return context
-  }, [sessionId, geolocation, parentContext, metadata])
+  }, [parentContext, metadata, sessionId, isBetaUser, geolocation])
   return <Context.Provider value={childContext}>{children}</Context.Provider>
 }
 

src/analytics/metadata.ts

@@ -9,6 +9,7 @@ export type BaseMetadata = {
   bundleDate: number
   referrerSrc: string
   referrerUrl: string
+  isBetaUser?: boolean
 }
 
 export type GeolocationMetadata = Geolocation
@@ -66,7 +67,7 @@ export function getMetadataForLogger({
   base,
   geolocation,
   session,
-}: Metadata): Record<string, any> {
+}: Metadata): Record<string, unknown> {
   return {
     deviceId: base.deviceId,
     sessionId: base.sessionId,