content: /*
   * Copyright (C) 2021 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 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 androidx.test.runner.suites;
  
  import static androidx.test.internal.runner.ClassPathScanner.getDefaultClasspaths;
  import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
  
  import androidx.annotation.RestrictTo;
  import androidx.annotation.RestrictTo.Scope;
  import androidx.test.internal.runner.ClassPathScanner;
  import androidx.test.internal.runner.ErrorReportingRunner;
  import androidx.test.internal.runner.TestLoader;
  import androidx.test.runner.suites.AndroidClasspathSuite.RunnerSuite;
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.List;
  import org.junit.runner.RunWith;
  import org.junit.runner.Runner;
  import org.junit.runners.Suite;
  import org.junit.runners.model.InitializationError;
  import org.junit.runners.model.RunnerBuilder;
  
  /**
   * Test suite that finds all JUnit3 and JUnit4 test classes in the instrumentation context apk.
   *
   * <p>This is intended to replicate the legacy AndroidJUnitRunner behavior of discovering and
   * running all tests when no '-e class' option is specified. e.g. the following AJUR invocations are
   * equivalent
   *
   * <p>'adb shell am instrument mypkg/androidx.test.runner.AndroidJUnitRunner' 'adb shell am
   * instrument -e class androidx.test.runner.suites.AndroidClasspathSuite
   * mypkg/androidx.test.runner.AndroidJUnitRunner'
   */
  @RunWith(RunnerSuite.class)
  public final class AndroidClasspathSuite {
  
    /**
     * Only called reflectively. Do not use programmatically.
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY)
    public AndroidClasspathSuite() {}
  
    /**
     * Internal suite class that performs the work of class path scanning.
     *
     * @hide
     */
    @RestrictTo(Scope.LIBRARY)
    public static class RunnerSuite extends Suite {
  
      /**
       * Only called reflectively. Do not use programmatically.
       *
       * @hide
       */
      @RestrictTo(Scope.LIBRARY)
      public RunnerSuite(Class<?> klass, RunnerBuilder builder) throws InitializationError {
        super(klass, getRunnersForClasses(builder));
      }
  
      private static List<Runner> getRunnersForClasses(RunnerBuilder builder) {
        try {
          Collection<String> classNames =
              new ClassPathScanner(getDefaultClasspaths(getInstrumentation())).getClassPathEntries();
          return TestLoader.Factory.create(null, builder, true).getRunnersFor(classNames);
        } catch (IOException e) {
          return Arrays.asList(
              new ErrorReportingRunner(
                  getInstrumentation().getContext().getPackageName(),
                  new RuntimeException(
                      "Failed to perform classpath scanning to determine tests to run", e)));
        }
      }
    }
  }
  