fix(hooks): update useFeature decisions when forced variation updates

src/Feature.spec.tsx

@@ -53,6 +53,7 @@ describe('<OptimizelyFeature>', () => {
         attributes: {},
       },
       isReady: jest.fn().mockReturnValue(false),
+      onForcedVariationsUpdate: jest.fn().mockReturnValue(() => {}),
     } as unknown) as ReactSDKClient;
   });
   it('throws an error when not rendered in the context of an OptimizelyProvider', () => {

src/hooks.spec.tsx

@@ -666,6 +666,24 @@ describe('hooks', () => {
       component.update();
       expect(isFeatureEnabledMock).not.toHaveBeenCalled();
     });
+
+    it('should re-render after setForcedVariation is called on the client', async () => {
+      isFeatureEnabledMock.mockReturnValue(false);
+      const component = Enzyme.mount(
+        <OptimizelyProvider optimizely={optimizelyMock}>
+          <MyFeatureComponent options={{ autoUpdate: true }} />
+        </OptimizelyProvider>
+      );
+
+      component.update();
+      expect(component.text()).toBe('false|{"foo":"bar"}|true|false');
+
+      isFeatureEnabledMock.mockReturnValue(true);
+      forcedVariationUpdateCallbacks[0]();
+
+      component.update();
+      expect(component.text()).toBe('true|{"foo":"bar"}|true|false');
+    });
   });
 
   describe('useDecision', () => {

src/hooks.ts

@@ -319,6 +319,17 @@ export const useFeature: UseFeature = (featureKey, options = {}, overrides = {})
     return (): void => {};
   }, [isClientReady, options.autoUpdate, optimizely, featureKey, getCurrentDecision]);
 
+  useEffect(
+    () =>
+      optimizely.onForcedVariationsUpdate(() => {
+        setState(prevState => ({
+          ...prevState,
+          ...getCurrentDecision(),
+        }));
+      }),
+    [getCurrentDecision, optimizely]
+  );
+
   return [state.isEnabled, state.variables, state.clientReady, state.didTimeout];
 };