code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you 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 org.openqa.selenium.support.decorators;
  
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.times;
  import static org.mockito.Mockito.verify;
  import static org.mockito.Mockito.verifyNoMoreInteractions;
  import static org.mockito.Mockito.when;
  
  import java.util.function.Consumer;
  import java.util.function.Function;
  import org.junit.jupiter.api.Tag;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.Alert;
  import org.openqa.selenium.WebDriver;
  
  @Tag("UnitTests")
  class DecoratedAlertTest {
  
    private static class Fixture {
  
      WebDriver originalDriver;
      WebDriver decoratedDriver;
      WebDriver.TargetLocator originalSwitch;
      Alert original;
      Alert decorated;
  
      public Fixture() {
        original = mock(Alert.class);
        originalSwitch = mock(WebDriver.TargetLocator.class);
        originalDriver = mock(WebDriver.class);
        when(originalSwitch.alert()).thenReturn(original);
        when(originalDriver.switchTo()).thenReturn(originalSwitch);
        decoratedDriver = new WebDriverDecorator<>().decorate(originalDriver);
        decorated = decoratedDriver.switchTo().alert();
      }
    }
  
    private void verifyFunction(Consumer<Alert> f) {
      Fixture fixture = new Fixture();
      f.accept(fixture.decorated);
      f.accept(verify(fixture.original, times(1)));
      verifyNoMoreInteractions(fixture.original);
    }
  
    private <R> void verifyFunction(Function<Alert, R> f, R result) {
      Fixture fixture = new Fixture();
      when(f.apply(fixture.original)).thenReturn(result);
      assertThat(f.apply(fixture.decorated)).isEqualTo(result);
      R ignore = f.apply(verify(fixture.original, times(1)));
      verifyNoMoreInteractions(fixture.original);
    }
  
    @Test
    void sendKeys() {
      verifyFunction($ -> $.sendKeys("test"));
    }
  
    @Test
    void accept() {
      verifyFunction(Alert::accept);
    }
  
    @Test
    void dismiss() {
      verifyFunction(Alert::dismiss);
    }
  
    @Test
    void getText() {
      verifyFunction(Alert::getText, "test");
    }
  }
  