Test TopTab navigationOptions is applied correctly (#2379)

* minor refactor - moved some logic from view o controller

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/toptabs/TopTabController.java

     @Override
     public void mergeNavigationOptions(NavigationOptions options) {
         this.options.mergeWith(options);
+        applyOptions(this.options);
     }
 
     String getTabTitle() {

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/toptabs/TopTabsAdapter.java

     public void onPageScrollStateChanged(int state) {
 
     }
+
+    int getCurrentItem() {
+        return currentPage;
+    }
 }

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/toptabs/TopTabsController.java

 
 import com.reactnativenavigation.parse.NavigationOptions;
 import com.reactnativenavigation.presentation.NavigationOptionsListener;
+import com.reactnativenavigation.utils.Task;
 import com.reactnativenavigation.viewcontrollers.ParentController;
 import com.reactnativenavigation.viewcontrollers.ViewController;
 import com.reactnativenavigation.views.TopTabsLayout;
 
     private List<TopTabController> tabs;
     private TopTabsLayout topTabsLayout;
+    private TopTabsAdapter adapter;
 
     public TopTabsController(Activity activity, String id, List<TopTabController> tabs) {
         super(activity, id);
         this.tabs = tabs;
+        this.adapter = new TopTabsAdapter(tabs);
         for (ViewController tab : tabs) {
             tab.setParentController(this);
         }
     @NonNull
     @Override
     protected ViewGroup createView() {
-        topTabsLayout = new TopTabsLayout(getActivity(), tabs);
+        topTabsLayout = new TopTabsLayout(getActivity(), tabs, adapter);
         return topTabsLayout;
     }
 
 
     @Override
     public void onViewAppeared() {
-        topTabsLayout.performOnCurrentTab(TopTabController::onViewAppeared);
+        performOnCurrentTab(TopTabController::onViewAppeared);
     }
 
     @Override
     public void onViewDisappear() {
-        topTabsLayout.performOnCurrentTab(TopTabController::onViewDisappear);
+        performOnCurrentTab(TopTabController::onViewDisappear);
     }
 
     @Override
     public void switchToTab(int index) {
         topTabsLayout.switchToTab(index);
     }
+
+    private void performOnCurrentTab(Task<TopTabController> task) {
+        task.run(tabs.get(adapter.getCurrentItem()));
+    }
 }

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/toptabs/TopTabsViewPager.java

     private static final int OFFSCREEN_PAGE_LIMIT = 99;
     private List<TopTabController> tabs;
 
-    public TopTabsViewPager(Context context, List<TopTabController> tabs) {
+    public TopTabsViewPager(Context context, List<TopTabController> tabs, TopTabsAdapter adapter) {
         super(context);
         this.tabs = tabs;
-        init();
+        init(adapter);
     }
 
-    private void init() {
+    private void init(TopTabsAdapter adapter) {
         setOffscreenPageLimit(OFFSCREEN_PAGE_LIMIT);
         for (ViewController tab : tabs) {
             addView(tab.getView(), new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
         }
-        TopTabsAdapter adapter = new TopTabsAdapter(tabs);
         setAdapter(adapter);
         addOnPageChangeListener(adapter);
     }

lib/android/app/src/main/java/com/reactnativenavigation/views/TopTabsLayout.java

 
 import com.reactnativenavigation.parse.NavigationOptions;
 import com.reactnativenavigation.presentation.OptionsPresenter;
-import com.reactnativenavigation.utils.Task;
 import com.reactnativenavigation.viewcontrollers.toptabs.TopTabController;
+import com.reactnativenavigation.viewcontrollers.toptabs.TopTabsAdapter;
 import com.reactnativenavigation.viewcontrollers.toptabs.TopTabsViewPager;
 
 import java.util.List;
 public class TopTabsLayout extends LinearLayout implements Container {
 
     private TopBar topBar;
-    private List<TopTabController> tabs;
     private TopTabsViewPager viewPager;
     private final OptionsPresenter optionsPresenter;
 
-    public TopTabsLayout(Context context, List<TopTabController> tabs) {
+    public TopTabsLayout(Context context, List<TopTabController> tabs, TopTabsAdapter adapter) {
         super(context);
         topBar = new TopBar(context);
-        this.tabs = tabs;
-        viewPager = new TopTabsViewPager(context, tabs);
         optionsPresenter = new OptionsPresenter(topBar, viewPager);
+        viewPager = new TopTabsViewPager(context, tabs, adapter);
         initViews();
     }
 
         return viewPager;
     }
 
-
-    public void performOnCurrentTab(Task<TopTabController> task) {
-        task.run(tabs.get(viewPager.getCurrentItem()));
-    }
-
     public void switchToTab(int index) {
         viewPager.setCurrentItem(index);
     }

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/TopTabControllerTest.java

+package com.reactnativenavigation.viewcontrollers;
+
+import android.app.Activity;
+
+import com.reactnativenavigation.BaseTest;
+import com.reactnativenavigation.mocks.TopTabLayoutMock;
+import com.reactnativenavigation.parse.NavigationOptions;
+import com.reactnativenavigation.viewcontrollers.toptabs.TopTabController;
+
+import org.junit.Test;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+public class TopTabControllerTest extends BaseTest {
+    private TopTabController uut;
+    private TopTabLayoutMock view;
+    private ParentController parentController;
+    private NavigationOptions initialOptions;
+
+    @Override
+    public void beforeEach() {
+        super.beforeEach();
+        Activity activity = newActivity();
+        view = spy(new TopTabLayoutMock(activity));
+        initialOptions = new NavigationOptions();
+        uut = new TopTabController(activity,
+                "containerId",
+                "containerName",
+                (activity1, containerId, containerName) -> view,
+                initialOptions
+        );
+        parentController = spy(new TopTabsControllerMock(activity, "parentContainerId"));
+        uut.setParentController(parentController);
+    }
+
+    @Test
+    public void styleIsAppliedOnParentControllerWhenTabIsVisible() throws Exception {
+        uut.ensureViewIsCreated();
+        uut.onViewAppeared();
+        verify(parentController, times(1)).applyOptions(initialOptions);
+    }
+
+    @Test
+    public void styleIsAppliedOnParentControllerWhenOptionsAreSetDynamically() throws Exception {
+        uut.ensureViewIsCreated();
+        uut.onViewAppeared();
+        uut.mergeNavigationOptions(new NavigationOptions());
+        verify(parentController, times(2)).applyOptions(initialOptions);
+    }
+
+}

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/TopTabsControllerMock.java

+package com.reactnativenavigation.viewcontrollers;
+
+import android.app.Activity;
+import android.support.annotation.NonNull;
+import android.view.ViewGroup;
+
+import java.util.Collection;
+
+public class TopTabsControllerMock extends ParentController {
+    public TopTabsControllerMock(Activity activity, String id) {
+        super(activity, id);
+    }
+
+    @NonNull
+    @Override
+    protected ViewGroup createView() {
+        return null;
+    }
+
+    @NonNull
+    @Override
+    public Collection<? extends ViewController> getChildControllers() {
+        return null;
+    }
+}

playground/src/containers/TopTabOptionsScreen.js

 const React = require('react');
 const { PureComponent } = require('react');
-
-const { View, Text } = require('react-native');
+const testIDs = require('../testIDs');
+const { View, Text, Button } = require('react-native');
+const Navigation = require('react-native-navigation');
 
 class TopTabOptionsScreen extends PureComponent {
   static get navigationOptions() {
     };
   }
 
+  constructor(props) {
+    super(props);
+    this.onClickDynamicOptions = this.onClickDynamicOptions.bind(this);
+  }
+
   render() {
     return (
       <View style={styles.root}>
         <Text style={styles.h1}>{this.props.text || 'Top Tab Screen'}</Text>
         <Text style={styles.footer}>{`this.props.containerId = ${this.props.containerId}`}</Text>
+        <Button title="Dynamic Options" testID={testIDs.DYNAMIC_OPTIONS_BUTTON} onPress={this.onClickDynamicOptions} />
       </View>
     );
   }
+
+  onClickDynamicOptions() {
+    Navigation.setOptions(this.props.containerId, {
+      topBar: {
+        title: 'Dynamic Title',
+        textColor: '#00FFFF',
+        largeTitle: false,
+        buttonColor: 'red',
+        textFontSize: 20,
+        textFontFamily: 'HelveticaNeue-CondensedBold'
+      }
+    });
+  }
 }
 
 const styles = {