chore: add ignored test for long polling and @PreserveOnRefresh (#10317)

* add IT to isolate the problem

* ignore until flow issue #10103 is fixed

flow-server/src/test/java/com/vaadin/flow/server/communication/PushHandlerTest.java

@@ -23,7 +23,6 @@
 import org.atmosphere.cpr.AtmosphereResource;
 import org.atmosphere.cpr.AtmosphereResource.TRANSPORT;
 import org.atmosphere.cpr.AtmosphereResourceEvent;
-import org.junit.After;
 import org.junit.Assert;
 import org.junit.Test;
 import org.mockito.Mockito;

flow-tests/test-root-context/src/main/java/com/vaadin/flow/uitest/ui/PushLongPollingWithPreserveOnRefreshView.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2000-2021 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.vaadin.flow.uitest.ui;
+
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.component.html.NativeButton;
+import com.vaadin.flow.component.page.Push;
+import com.vaadin.flow.router.PreserveOnRefresh;
+import com.vaadin.flow.router.Route;
+import com.vaadin.flow.shared.ui.Transport;
+
+@PreserveOnRefresh
+@Push(transport = Transport.LONG_POLLING)
+@Route("com.vaadin.flow.uitest.ui.PushLongPollingWithPreserveOnRefreshView")
+public class PushLongPollingWithPreserveOnRefreshView extends Div {
+
+    public static final String ADD_BUTTON_ID = "add-button-id";
+    public static final String TEST_DIV_ID = "test-div-id";
+    public static final String TEXT_IN_DIV = "text in div";
+
+    public PushLongPollingWithPreserveOnRefreshView() {
+        NativeButton button = new NativeButton("Open Dialog",
+                e -> e.getSource().getUI().ifPresent(ui -> {
+                    Div div = new Div();
+                    div.setText(TEXT_IN_DIV);
+                    div.setId(TEST_DIV_ID);
+                    ui.add(div);
+                }));
+        button.setId(ADD_BUTTON_ID);
+        add(button);
+    }
+}

flow-tests/test-root-context/src/test/java/com/vaadin/flow/uitest/ui/PushLongPollingWithPreserveOnRefreshIT.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2000-2021 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.vaadin.flow.uitest.ui;
+
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.NoSuchElementException;
+
+import com.vaadin.flow.testcategory.IgnoreOSGi;
+import com.vaadin.flow.testutil.ChromeBrowserTest;
+
+import static com.vaadin.flow.uitest.ui.PushLongPollingWithPreserveOnRefreshView.ADD_BUTTON_ID;
+import static com.vaadin.flow.uitest.ui.PushLongPollingWithPreserveOnRefreshView.TEST_DIV_ID;
+import static com.vaadin.flow.uitest.ui.PushLongPollingWithPreserveOnRefreshView.TEXT_IN_DIV;
+
+@Category(IgnoreOSGi.class)
+public class PushLongPollingWithPreserveOnRefreshIT extends ChromeBrowserTest {
+
+    @Ignore("https://github.com/vaadin/flow/issues/10103")
+    @Test
+    public void addDiv_refreshThePage_ensureNoErrorHappensAndDivIsPresent() {
+
+        open();
+
+        waitPageLoad();
+
+        findElement(By.id(ADD_BUTTON_ID)).click();
+
+        ensureDivIsPresent();
+
+        // refresh the browser
+        getDriver().navigate().refresh();
+
+        waitPageLoad();
+
+        ensureNoErrorIsDisplayed();
+
+        ensureDivIsPresent();
+    }
+
+    private void waitPageLoad() {
+        WebElement loadingIndicator = findElement(
+                By.className("v-loading-indicator"));
+        waitUntil(driver -> !loadingIndicator.isDisplayed());
+    }
+
+    private void ensureNoErrorIsDisplayed() {
+        Assert.assertThrows(NoSuchElementException.class,
+                () -> findElement(By.className("v-system-error")));
+    }
+
+    private void ensureDivIsPresent() {
+        WebElement div = findElement(By.id(TEST_DIV_ID));
+
+        Assert.assertNotNull(div);
+        Assert.assertEquals(TEXT_IN_DIV, div.getText());
+    }
+}