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.os;
  
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  import static org.assertj.core.api.Assumptions.assumeThat;
  import static org.openqa.selenium.Platform.WINDOWS;
  import static org.openqa.selenium.testing.TestUtilities.isOnTravis;
  
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.Platform;
  import org.openqa.selenium.build.BazelBuild;
  
  class OsProcessTest {
  
    private static final String testExecutable =
        findExecutable("java/test/org/openqa/selenium/os/echo");
  
    private OsProcess process = new OsProcess(testExecutable);
  
    @Test
    void testSetEnvironmentVariableWithNullKeyThrows() {
      String key = null;
      String value = "Bar";
      assertThatExceptionOfType(IllegalArgumentException.class)
          .isThrownBy(() -> process.setEnvironmentVariable(key, value));
      assertThat(process.getEnvironment()).doesNotContainValue(value);
    }
  
    @Test
    void testSetEnvironmentVariableWithNullValueThrows() {
      String key = "Foo";
      String value = null;
      assertThatExceptionOfType(IllegalArgumentException.class)
          .isThrownBy(() -> process.setEnvironmentVariable(key, value));
      assertThat(process.getEnvironment()).doesNotContainKey(key);
    }
  
    @Test
    void testSetEnvironmentVariableWithNonNullValueSets() {
      String key = "Foo";
      String value = "Bar";
      process.setEnvironmentVariable(key, value);
      assertThat(process.getEnvironment()).containsEntry(key, value);
    }
  
    @Test
    void testDestroy() {
      process.executeAsync();
      assertThat(process.isRunning()).isTrue();
      process.destroy();
      assertThat(process.isRunning()).isFalse();
    }
  
    @Test
    void canHandleOutput() throws InterruptedException {
      process = new OsProcess(testExecutable, "ping");
      process.executeAsync();
      process.waitFor();
      assertThat(process.getStdOut()).isNotEmpty().contains("ping");
    }
  
    @Test
    void canCopyOutput() throws InterruptedException {
      process = new OsProcess(testExecutable, "Who", "else", "likes", "cheese?");
      ByteArrayOutputStream buffer = new ByteArrayOutputStream();
      process.copyOutputTo(buffer);
      process.executeAsync();
      process.waitFor();
      assertThat(buffer.toByteArray()).isNotEmpty();
      assertThat(process.getStdOut()).isEqualTo(buffer.toString());
    }
  
    @Test
    void canDetectSuccess() throws InterruptedException {
      assumeThat(isOnTravis()).as("Operation not permitted on travis").isFalse();
      OsProcess process =
          new OsProcess(
              testExecutable, (Platform.getCurrent().is(WINDOWS) ? "-n" : "-c"), "3", "localhost");
      process.executeAsync();
      process.waitFor();
      assertThat(process.getExitCode()).isZero();
    }
  
    @Test
    void canDetectFailure() throws InterruptedException {
      process.executeAsync();
      process.waitFor();
      assertThat(process.getExitCode()).isNotEqualTo(0);
    }
  
    private static String findExecutable(String relativePath) {
      if (Platform.getCurrent().is(Platform.WINDOWS)) {
        File workingDir = BazelBuild.findBinRoot(new File(".").getAbsoluteFile());
        return new File(workingDir, relativePath).getAbsolutePath();
      } else {
        return relativePath;
      }
    }
  }
  