Flow to hilla navigation.

vaadin-platform-react-hybrid-test/src/main/java/com/vaadin/platform/react/test/views/FlowHillaView.java

@@ -17,6 +17,7 @@ public class FlowHillaView extends HorizontalLayout {
     private Button sayHello;
 
     public FlowHillaView() {
+        setId("flow-hilla");
         setPadding(true);
         setSpacing(true);
         name = new TextField("Your name for Flow");

vaadin-platform-react-hybrid-test/src/main/java/com/vaadin/platform/react/test/views/FlowMainView.java

@@ -7,6 +7,8 @@
 @Route("flow")
 public class FlowMainView extends VerticalLayout {
     public FlowMainView() {
-        add(new Span("Flow root view for menu!"));
+        Span span = new Span("Flow root view for menu!");
+        span.setId("flow-main");
+        add(span);
     }
 }

vaadin-platform-react-hybrid-test/src/test/java/com/vaadin/platform/react/test/FlowInHillaIT.java

@@ -0,0 +1,31 @@
+package com.vaadin.platform.react.test;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.support.ui.ExpectedConditions;
+
+import com.vaadin.flow.component.sidenav.testbench.SideNavItemElement;
+
+public class FlowInHillaIT extends AbstractPlatformTest{
+
+    @Test
+    public void flowViewInHillaLayout() {
+        Assert.assertNotNull(findElement(By.id("hilla")));
+
+        // Navigate to Flow view
+        $(SideNavItemElement.class).withCaption("Flow in hilla").first().click();
+
+        waitUntil(ExpectedConditions.presenceOfElementLocated(By.id("flow-hilla")));
+
+        Assert.assertNull("Showing hilla placeholder even though Flow should be shown", findElement(By.id("placeholder")));
+
+        // navigate away from Flow view
+        $(SideNavItemElement.class).withCaption("React Components").first().click();
+    }
+
+    @Override
+    protected String getTestPath() {
+        return "/hilla";
+    }
+}

vaadin-platform-react-hybrid-test/src/test/java/com/vaadin/platform/react/test/HillaInFlowIT.java

@@ -0,0 +1,31 @@
+package com.vaadin.platform.react.test;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.support.ui.ExpectedConditions;
+
+import com.vaadin.flow.component.sidenav.testbench.SideNavItemElement;
+
+public class HillaInFlowIT extends AbstractPlatformTest{
+
+    @Test
+    public void hillaViewInFlowLayout() {
+        waitUntil(ExpectedConditions.presenceOfElementLocated(By.id("flow-main")));
+
+        // Navigate to Flow view
+        $(SideNavItemElement.class).withCaption("Flow in hilla").first().click();
+
+        waitUntil(ExpectedConditions.presenceOfElementLocated(By.id("flow-hilla")));
+
+        Assert.assertNull("Showing hilla placeholder even though Flow should be shown", findElement(By.id("placeholder")));
+
+        // navigate away from Flow view
+        $(SideNavItemElement.class).withCaption("React Components").first().click();
+    }
+
+    @Override
+    protected String getTestPath() {
+        return "/flow";
+    }
+}