[FSSDK-12294] shared hook addition

Author: junaed-optimizely

src/hooks/useDecide.ts

@@ -14,11 +14,11 @@
  * limitations under the License.
  */
 
-import { useCallback, useEffect, useMemo, useState } from 'react';
-import { useSyncExternalStore } from 'use-sync-external-store/shim';
+import { useEffect, useMemo, useState } from 'react';
 import type { OptimizelyDecideOption, OptimizelyDecision } from '@optimizely/optimizely-sdk';
 
 import { useOptimizelyContext } from './useOptimizelyContext';
+import { useProviderState } from './useProviderState';
 import { useStableArray } from './useStableArray';
 
 export interface UseDecideConfig {
@@ -43,12 +43,7 @@ export type UseDecideResult =
 export function useDecide(flagKey: string, config?: UseDecideConfig): UseDecideResult {
   const { store, client } = useOptimizelyContext();
   const decideOptions = useStableArray(config?.decideOptions);
-  // --- General state subscription ---
-  // store.getState() returns a new object on every state change,
-  // so Object.is comparison works naturally.
-  const subscribeState = useCallback((onStoreChange: () => void) => store.subscribe(onStoreChange), [store]);
-  const getStateSnapshot = useCallback(() => store.getState(), [store]);
-  const state = useSyncExternalStore(subscribeState, getStateSnapshot, getStateSnapshot);
+  const state = useProviderState(store);
 
   // --- Forced decision subscription ---
   // Forced decisions don't change store state, so we use a version counter

src/hooks/useDecideAll.ts

@@ -14,10 +14,10 @@
  * limitations under the License.
  */
 
-import { useCallback, useEffect, useMemo, useState } from 'react';
-import { useSyncExternalStore } from 'use-sync-external-store/shim';
+import { useEffect, useMemo, useState } from 'react';
 
 import { useOptimizelyContext } from './useOptimizelyContext';
+import { useProviderState } from './useProviderState';
 import { useStableArray } from './useStableArray';
 import type { UseDecideConfig } from './useDecide';
 import type { UseDecideMultiResult } from './useDecideForKeys';
@@ -34,11 +34,7 @@ import type { UseDecideMultiResult } from './useDecideForKeys';
 export function useDecideAll(config?: UseDecideConfig): UseDecideMultiResult {
   const { store, client } = useOptimizelyContext();
   const decideOptions = useStableArray(config?.decideOptions);
-
-  // --- General state subscription ---
-  const subscribeState = useCallback((onStoreChange: () => void) => store.subscribe(onStoreChange), [store]);
-  const getStateSnapshot = useCallback(() => store.getState(), [store]);
-  const state = useSyncExternalStore(subscribeState, getStateSnapshot, getStateSnapshot);
+  const state = useProviderState(store);
 
   // --- Forced decision subscription — any flag key ---
   const [fdVersion, setFdVersion] = useState(0);

src/hooks/useDecideForKeys.ts

@@ -14,11 +14,11 @@
  * limitations under the License.
  */
 
-import { useCallback, useEffect, useMemo, useState } from 'react';
-import { useSyncExternalStore } from 'use-sync-external-store/shim';
+import { useEffect, useMemo, useState } from 'react';
 import type { OptimizelyDecision } from '@optimizely/optimizely-sdk';
 
 import { useOptimizelyContext } from './useOptimizelyContext';
+import { useProviderState } from './useProviderState';
 import { useStableArray } from './useStableArray';
 import type { UseDecideConfig } from './useDecide';
 
@@ -42,11 +42,7 @@ export function useDecideForKeys(flagKeys: string[], config?: UseDecideConfig):
   const { store, client } = useOptimizelyContext();
   const stableKeys = useStableArray(flagKeys);
   const decideOptions = useStableArray(config?.decideOptions);
-
-  // --- General state subscription ---
-  const subscribeState = useCallback((onStoreChange: () => void) => store.subscribe(onStoreChange), [store]);
-  const getStateSnapshot = useCallback(() => store.getState(), [store]);
-  const state = useSyncExternalStore(subscribeState, getStateSnapshot, getStateSnapshot);
+  const state = useProviderState(store);
 
   // --- Forced decision subscription — per-key with shared version counter ---
   const [fdVersion, setFdVersion] = useState(0);

src/hooks/useProviderState.ts

@@ -0,0 +1,31 @@
+/**
+ * Copyright 2026, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { useCallback } from 'react';
+import { useSyncExternalStore } from 'use-sync-external-store/shim';
+import type { ProviderState } from '../provider/index';
+import type { ProviderStateStore } from '../provider/index';
+
+/**
+ * Subscribes to the `ProviderStateStore` via `useSyncExternalStore`
+ * and returns the current provider state.
+ */
+export function useProviderState(store: ProviderStateStore): ProviderState {
+  const subscribeState = useCallback((onStoreChange: () => void) => store.subscribe(onStoreChange), [store]);
+  const getStateSnapshot = useCallback(() => store.getState(), [store]);
+
+  return useSyncExternalStore(subscribeState, getStateSnapshot, getStateSnapshot);
+}