fix: guard against undefined client in useFeatureFlagEnabled (#2655)

* guard against undefined client

* changeset

* Update .changeset/puny-rules-hide.md

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

* add guard to other hooks

---------

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Author: ordehi

.changeset/puny-rules-hide.md

@@ -0,0 +1,5 @@
+---
+'@posthog/react': patch
+---
+
+Updated feature flag hooks to properly check if client is initialized and prevent client is undefined errors

packages/react/src/hooks/useActiveFeatureFlags.ts

@@ -13,7 +13,7 @@ export function useActiveFeatureFlags(): string[] {
     }, [client])
 
     // if the client is not loaded yet and we have a bootstrapped value, use it
-    if (!client.featureFlags.hasLoadedFlags && bootstrap?.featureFlags) {
+    if (!client?.featureFlags?.hasLoadedFlags && bootstrap?.featureFlags) {
         return Object.keys(bootstrap.featureFlags)
     }
 

packages/react/src/hooks/useFeatureFlagEnabled.ts

@@ -16,7 +16,7 @@ export function useFeatureFlagEnabled(flag: string): boolean | undefined {
     const bootstrapped = bootstrap?.featureFlags?.[flag]
 
     // if the client is not loaded yet, check if we have a bootstrapped value and then true/false it
-    if (!client.featureFlags.hasLoadedFlags && bootstrap?.featureFlags) {
+    if (!client?.featureFlags?.hasLoadedFlags && bootstrap?.featureFlags) {
         return isUndefined(bootstrapped) ? undefined : !!bootstrapped
     }
 

packages/react/src/hooks/useFeatureFlagPayload.ts

@@ -14,7 +14,7 @@ export function useFeatureFlagPayload(flag: string): JsonType {
     }, [client, flag])
 
     // if the client is not loaded yet, use the bootstrapped value
-    if (!client.featureFlags.hasLoadedFlags && bootstrap?.featureFlagPayloads) {
+    if (!client?.featureFlags?.hasLoadedFlags && bootstrap?.featureFlagPayloads) {
         return bootstrap.featureFlagPayloads[flag]
     }
 

packages/react/src/hooks/useFeatureFlagVariantKey.ts

@@ -14,7 +14,7 @@ export function useFeatureFlagVariantKey(flag: string): string | boolean | undef
         })
     }, [client, flag])
 
-    if (!client.featureFlags.hasLoadedFlags && bootstrap?.featureFlags) {
+    if (!client?.featureFlags?.hasLoadedFlags && bootstrap?.featureFlags) {
         return bootstrap.featureFlags[flag]
     }