Support null bottomTab.badge

e2e/ScreenStyle.test.js

     await expect(element(by.text('TeSt'))).toBeVisible();
   });
 
+  test('set Tab Bar badge null on a current Tab should reset badge', async () => {
+    await elementById(testIDs.TAB_BASED_APP_BUTTON).tap();
+    await elementById(testIDs.SET_TAB_BADGE_BUTTON).tap();
+    await expect(element(by.text('TeSt'))).toBeVisible();
+    await elementById(testIDs.SET_TAB_BADGE_BUTTON_NULL).tap();
+    await expect(element(by.text('TeSt'))).toBeNotVisible();
+  });
+
   test(':android: hide Tab Bar', async () => {
     await elementById(testIDs.TAB_BASED_APP_BUTTON).tap();
     await expect(elementById(testIDs.BOTTOM_TABS_ELEMENT)).toBeVisible();

lib/ios/ReactNativeNavigationTests/UIViewController+RNNOptionsTest.m

 
 - (void)setUp {
     [super setUp];
+	self.uut = [UIViewController new];
+}
+
+- (void)test_setTabBarItemBadge_shouldSetValidValue {
+	NSString* badgeValue = @"badge";
+	[self.uut rnn_setTabBarItemBadge:badgeValue];
+	XCTAssertEqual(self.uut.tabBarItem.badgeValue, badgeValue);
+}
+
+- (void)test_setTabBarItemBadge_shouldResetWhenValueIsEmptyString {
+	[self.uut rnn_setTabBarItemBadge:@"badge"];
+	NSString* badgeValue = @"";
+	[self.uut rnn_setTabBarItemBadge:badgeValue];
+	XCTAssertEqual(self.uut.tabBarItem.badgeValue, nil);
+}
+
+- (void)test_setTabBarItemBadge_shouldResetWhenValueIsNullObject {
+	[self.uut rnn_setTabBarItemBadge:@"badge"];
+	NSNull* nullBadgeValue = [NSNull new];
+	[self.uut rnn_setTabBarItemBadge:nullBadgeValue];
+	XCTAssertEqual(self.uut.tabBarItem.badgeValue, nil);
 }
 
 @end

lib/ios/TextParser.m

 @implementation TextParser
 
 + (Text *)parse:(NSDictionary *)json key:(NSString *)key {
-	return json[key] && ![json[key] isKindOfClass:[NSNull class]] ? [[Text alloc] initWithValue:[RCTConvert NSString:json[key]]] : [NullText new];
+	return json[key] ? [[Text alloc] initWithValue:json[key]] : [NullText new];
 }
 
 @end

lib/ios/UIViewController+RNNOptions.m

 
 - (void)rnn_setTabBarItemBadge:(NSString *)badge {
 	UITabBarItem *tabBarItem = self.tabBarItem;
-	tabBarItem.badgeValue = badge;
 	
 	if ([badge isKindOfClass:[NSNull class]] || [badge isEqualToString:@""]) {
 		tabBarItem.badgeValue = nil;
+	} else {
+		tabBarItem.badgeValue = badge;
 	}
 }
 

playground/src/screens/TextScreen.js

           {this.renderTextFromFunctionInProps()}
           <Text style={styles.footer}>{`this.props.componentId = ${this.props.componentId}`}</Text>
           <Button title={'Set Tab Badge'} testID={testIDs.SET_TAB_BADGE_BUTTON} onPress={() => this.onClickSetBadge()} />
+          <Button title={'Set empty Tab Badge'} testID={testIDs.SET_TAB_BADGE_BUTTON_NULL} onPress={() => this.onClickSetNullBadge()} />
           <Button title={'Switch To Tab 2'} testID={testIDs.SWITCH_SECOND_TAB_BUTTON} onPress={() => this.onClickSwitchToTab()} />
           <Button title={'Switch To Tab 1 by componentID'} testID={testIDs.SWITCH_FIRST_TAB_BUTTON} onPress={() => this.onClickSwitchToTabByComponentID()} />
           {/* tslint:disable-next-line:max-line-length */}
     });
   }
 
+  onClickSetNullBadge() {
+    Navigation.mergeOptions(this.props.componentId, {
+      bottomTab: {
+        badge: null
+      }
+    });
+  }
+
   onClickPush = async () => {
     await Navigation.push(this.props.componentId, {
       component: {

playground/src/testIDs.js

   SHOW_SNACKBAR_BUTTON: `SHOW_SNACKBAR_BUTTON`,
   TOGGLE_TOP_BAR_HIDE_ON_SCROLL: `TOGGLE_TOP_BAR_HIDE_ON_SCROLL`,
   SET_TAB_BADGE_BUTTON: `SET_TAB_BADGE_BUTTON`,
+  SET_TAB_BADGE_BUTTON_NULL: `SET_TAB_BADGE_BUTTON_NULL`,
   PUSH_TO_TEST_DID_DISAPPEAR_BUTTON: `PUSH_TO_TEST_DID_DISAPPEAR_BUTTON`,
   PUSH_BUTTON_WAIT_FOR_RENDER: `PUSH_AND_WAIT_FOR_RENDER`,
   SHOW_LEFT_SIDE_MENU_BUTTON: `SHOW_LEFT_SIDE_MENU_BUTTON`,