fix: auto dismiss dialogs if there are no listeners (#252)

playwright/src/main/java/com/microsoft/playwright/impl/PageImpl.java

@@ -110,10 +110,11 @@ public class PageImpl extends ChannelOwner implements Page {
     if ("dialog".equals(event)) {
       String guid = params.getAsJsonObject("dialog").get("guid").getAsString();
       DialogImpl dialog = connection.getExistingObject(guid);
-      // If no action taken the dialog will stay open and execution will hang. We
-      // could automatically dismiss the dialog if there are no listeners but we want
-      // the behavior to match upstream one.
-      listeners.notify(EventType.DIALOG, dialog);
+      if (listeners.hasListeners(EventType.DIALOG)) {
+        listeners.notify(EventType.DIALOG, dialog);
+      } else {
+        dialog.dismiss();
+      }
     } else if ("popup".equals(event)) {
       String guid = params.getAsJsonObject("page").get("guid").getAsString();
       PageImpl popup = connection.getExistingObject(guid);

playwright/src/test/java/com/microsoft/playwright/TestPageDialog.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) Microsoft Corporation.
+ *
+ * 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.microsoft.playwright;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class TestPageDialog extends TestBase {
+  @Test
+  void shouldFire() {
+    page.onDialog(dialog -> {
+      assertEquals("alert", dialog.type());
+      assertEquals("", dialog.defaultValue());
+      assertEquals("yo", dialog.message());
+      dialog.accept();
+    });
+    page.evaluate("alert('yo')");
+  }
+
+  @Test
+  void shouldAllowAcceptingPrompts() {
+    page.onDialog(dialog -> {
+      assertEquals("prompt", dialog.type());
+      assertEquals("yes.", dialog.defaultValue());
+      assertEquals("question?", dialog.message());
+      dialog.accept("answer!");
+    });
+    Object result = page.evaluate("prompt('question?', 'yes.')");
+    assertEquals("answer!", result);
+  }
+
+  @Test
+  void shouldDismissThePrompt() {
+    page.onDialog(dialog -> {
+      dialog.dismiss();
+    });
+    Object result = page.evaluate("prompt('question?')");
+    assertNull(result);
+  }
+
+  @Test
+  void shouldAcceptTheConfirmPrompt() {
+    page.onDialog(dialog -> {
+      dialog.accept();
+    });
+    Object result = page.evaluate("confirm('boolean?')");
+    assertEquals(true, result);
+  }
+
+  @Test
+  void shouldDismissTheConfirmPrompt() {
+    page.onDialog(dialog -> {
+      dialog.dismiss();
+    });
+    Object result = page.evaluate("() => confirm('boolean?')");
+    assertEquals(false, result);
+  }
+
+  @Test
+  void shouldBeAbleToCloseContextWithOpenAlert() {
+    Page page = context.newPage();
+    boolean[] didShowDialog = {false};
+    page.onDialog(dialog -> didShowDialog[0] = true);
+    page.evaluate("() => setTimeout(() => alert('hello'), 0)");
+    while (!didShowDialog[0]) {
+      page.waitForTimeout(100);
+    }
+  }
+
+  @Test
+  void shouldHandleMultipleAlerts() {
+    page.onDialog(dialog -> {
+      dialog.accept();
+    });
+    page.setContent("<p>Hello World</p>\n" +
+      "<script>\n" +
+      "  alert('Please dismiss this dialog');\n" +
+      "  alert('Please dismiss this dialog');\n" +
+      "  alert('Please dismiss this dialog');\n" +
+      "</script>\n");
+    assertEquals("Hello World", page.textContent("p"));
+  }
+
+  @Test
+  void shouldHandleMultipleConfirms() {
+    page.onDialog(dialog -> {
+      dialog.accept();
+    });
+    page.setContent("<p>Hello World</p>\n" +
+      "<script>\n" +
+      "  confirm('Please confirm me?');\n" +
+      "  confirm('Please confirm me?');\n" +
+      "  confirm('Please confirm me?');\n" +
+      "</script>\n");
+    assertEquals("Hello World", page.textContent("p"));
+  }
+
+  @Test
+  void shouldAutoDismissThePromptWithoutListeners() {
+    Object result = page.evaluate("() => prompt('question?')");
+    assertNull(result);
+  }
+
+  @Test
+  void shouldAutoDismissTheAlertWithoutListeners() {
+    page.setContent("<div onclick='window.alert(123); window._clicked=true'>Click me</div>");
+    page.click("div");
+    assertEquals(true, page.evaluate("window._clicked"));
+  }
+
+}