| /* |
| * Copyright (C) 2019 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 libcore.junit.util; |
| |
| import static org.junit.Assert.fail; |
| |
| import java.lang.annotation.ElementType; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.lang.annotation.Target; |
| import java.lang.reflect.Method; |
| import org.junit.rules.TestRule; |
| import org.junit.runner.Description; |
| import org.junit.runners.model.Statement; |
| |
| /** |
| * Allows tests to specify the target SDK version that they want to run as. |
| * |
| * <p>To use add the following to the test class. It will only change the behavior of a test method |
| * if it is annotated with {@link TargetSdkVersion}. |
| * |
| * <pre> |
| * @Rule |
| * public TestRule switchTargetSdkVersionRule = SwitchTargetSdkVersionRule.getInstance(); |
| * </pre> |
| * |
| * <p>Each test method that needs to run with a specific target SDK version needs to be annotated |
| * with {@link TargetSdkVersion} specifying the required SDK version. e.g. |
| * |
| * <pre> |
| * @Test |
| * @TargetSdkVersion(23) |
| * public void testAsIfTargetedAtSDK23() { |
| * assertEquals(23, VMRuntime.getRuntime().getTargetSdkVersion()); |
| * } |
| * </pre> |
| * |
| * <p>Within the body of the method the {@code VMRuntime.getTargetSdkVersion()} will be set to the |
| * value specified in the annotation. |
| * |
| * <p>If used on a platform that does not support the {@code dalvik.system.VMRuntime} class then any |
| * test annotated with {@link TargetSdkVersion} will fail with a message explaining that it is not |
| * supported. |
| */ |
| public abstract class SwitchTargetSdkVersionRule implements TestRule { |
| |
| private static final TestRule INSTANCE; |
| |
| private static final String VMRUNTIME = "dalvik.system.VMRuntime"; |
| |
| // Use reflection so that this rule can compile and run against RI core libraries. |
| static { |
| TestRule rule; |
| try { |
| // Assume that VMRuntime is supported and create a rule instance that will use it. |
| rule = new SwitchVMRuntimeUsingReflection(); |
| } catch (ClassNotFoundException | NoSuchMethodException e) { |
| // VMRuntime is not supported. |
| rule = new VMRuntimeNotSupported(); |
| } |
| |
| INSTANCE = rule; |
| } |
| |
| public static TestRule getInstance() { |
| return INSTANCE; |
| } |
| |
| @Retention(RetentionPolicy.RUNTIME) |
| @Target(ElementType.METHOD) |
| public @interface TargetSdkVersion { |
| int value(); |
| } |
| |
| private SwitchTargetSdkVersionRule() { |
| } |
| |
| @Override |
| public Statement apply(final Statement statement, Description description) { |
| TargetSdkVersion targetSdkVersion = description.getAnnotation(TargetSdkVersion.class); |
| if (targetSdkVersion == null) { |
| return statement; |
| } |
| |
| return createStatement(statement, targetSdkVersion.value()); |
| } |
| |
| /** |
| * Create the {@link Statement} that will be run for the specific {@code targetSdkVersion}. |
| * |
| * @param statement the {@link Statement} encapsulating the test method. |
| * @param targetSdkVersion the target SDK version to use within the body of the test. |
| * @return the created {@link Statement}. |
| */ |
| protected abstract Statement createStatement(Statement statement, int targetSdkVersion); |
| |
| /** |
| * Switch the value of {@code VMRuntime.getTargetSdkVersion()} for tests annotated with |
| * {@link TargetSdkVersion}. |
| * |
| * <p>Uses reflection so this class can compile and run on OpenJDK. |
| */ |
| private static class SwitchVMRuntimeUsingReflection extends SwitchTargetSdkVersionRule { |
| |
| private final Method runtimeInstanceGetter; |
| private final Method targetSdkVersionGetter; |
| private final Method targetSdkVersionSetter; |
| |
| private SwitchVMRuntimeUsingReflection() throws ClassNotFoundException, NoSuchMethodException { |
| ClassLoader classLoader = ClassLoader.getSystemClassLoader(); |
| Class<?> runtimeClass = classLoader.loadClass(VMRUNTIME); |
| |
| this.runtimeInstanceGetter = runtimeClass.getMethod("getRuntime"); |
| this.targetSdkVersionGetter = runtimeClass.getMethod("getTargetSdkVersion"); |
| this.targetSdkVersionSetter = runtimeClass.getMethod("setTargetSdkVersion", int.class); |
| } |
| |
| @Override |
| protected Statement createStatement(Statement statement, int targetSdkVersion) { |
| return new Statement() { |
| @Override |
| public void evaluate() throws Throwable { |
| Object runtime = runtimeInstanceGetter.invoke(null); |
| int oldTargetSdkVersion = (int) targetSdkVersionGetter.invoke(runtime); |
| try { |
| targetSdkVersionSetter.invoke(runtime, targetSdkVersion); |
| statement.evaluate(); |
| } finally { |
| targetSdkVersionSetter.invoke(runtime, oldTargetSdkVersion); |
| } |
| } |
| }; |
| } |
| } |
| |
| /** |
| * VMRuntime is not supported on this platform so fail all tests that target a specific SDK |
| * version |
| */ |
| private static class VMRuntimeNotSupported extends SwitchTargetSdkVersionRule { |
| |
| @Override |
| protected Statement createStatement(Statement statement, int targetSdkVersion) { |
| return new Statement() { |
| @Override |
| public void evaluate() { |
| fail("Targeting SDK version not supported as " + VMRUNTIME + " is not supported"); |
| } |
| }; |
| } |
| } |
| } |