content: /*
   * Copyright (C) 2015 The Android Open Source Project
   *
   * 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 Lice`nse 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 androidx.test.rule;
  
  import android.os.Debug;
  import org.junit.rules.TestRule;
  import org.junit.runner.Description;
  import org.junit.runners.model.Statement;
  
  /**
   * The {@code DisableOnAndroidDebug} Rule allows you to label certain rules to be disabled when
   * debugging.
   *
   * <p>The most illustrative use case is for tests that make use of the {@link
   * org.junit.rules.Timeout} rule, when ran in debug mode the test may terminate on timeout abruptly
   * during debugging. Developers may disable the timeout, or increase the timeout by making a code
   * change on tests that need debugging and remember revert the change afterwards or rules such as
   * {@link org.junit.rules.Timeout} that may be disabled during debugging may be wrapped in a {@code
   * DisableOnDebug}.
   *
   * <p>The important benefit of this feature is that you can disable such rules without any making
   * any modifications to your test class to remove them during debugging.
   *
   * <p>This does nothing to tackle timeouts or time sensitive code under test when debugging and may
   * make this less useful in such circumstances.
   *
   * <p>Example usage:
   *
   * <pre>
   * public static class DisableTimeoutOnDebugSampleTest {
   *
   *     &#064;Rule
   *     public TestRule timeout = new DisableOnAndroidDebug(new Timeout(20));
   *
   *     &#064;Test
   *     public void myTest() {
   *         int i = 0;
   *         assertEquals(0, i); // suppose you had a break point here to inspect i
   *     }
   * }
   * </pre>
   */
  // NOTE The docs and API of this class is copied from JUnit 4.12. The implementation is not.
  public class DisableOnAndroidDebug implements TestRule {
    private final TestRule rule;
  
    /**
     * Wrap another {@link TestRule} and conditionally disable it when a debugger is attached.
     *
     * @param rule to disable during debugging
     */
    public DisableOnAndroidDebug(TestRule rule) {
      this.rule = rule;
    }
  
    /** {@inheritDoc} */
    @Override
    public final Statement apply(final Statement base, Description description) {
      if (isDebugging()) {
        return base;
      }
      return rule.apply(base, description);
    }
  
    /**
     * Returns {@code true} if the VM has a debugger connected. This method may be used by test
     * classes to take additional action to disable code paths that interfere with debugging if
     * required.
     *
     * @return {@code true} if a debugger is connected, {@code false} otherwise
     */
    public boolean isDebugging() {
      return Debug.isDebuggerConnected();
    }
  }
  