Add ApexInstallHelper

This is a utility to help installing and updating apexes in tests as
well as cleaning them up when the test finishes.

Test: manually by using the code to install apexes, make sure they were
installed and also that they were removed after the test.

Change-Id: Iac881661b90332c9612c11f916f6df7d8e671aa8

java/com/android/modules/testing/utils/Android.bp

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2022 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 {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+java_library_host {
+    name: "com.android.modules.testing.utils",
+    visibility: ["//visibility:public"],
+    srcs: [
+        "ApexInstallHelper.java"
+    ],
+    libs: ["tradefed"],
+    static_libs: [
+        "cts-install-lib-host",
+        "frameworks-base-hostutils",
+    ],
+}

java/com/android/modules/testing/utils/ApexInstallHelper.java

@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2022 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 com.android.modules.testing.utils;
+
+import static org.junit.Assert.assertTrue;
+
+import android.cts.install.lib.host.InstallUtilsHost;
+
+import com.android.tradefed.device.ITestDevice;
+import com.android.tradefed.invoker.TestInformation;
+
+import com.android.internal.util.test.SystemPreparer;
+import com.android.internal.util.test.SystemPreparer.DeviceProvider;
+import com.android.internal.util.test.SystemPreparer.RebootStrategy;
+
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+
+/**
+ * Utility to help installing and updating apexes in tests as well as cleaning them up when the test
+ * finishes.
+ *
+ * <p>Install vs updating: you can update any apex preinstalled in the system image as long as your
+ * apex has a higher version than the one currently installed using
+ * {@link #installApexAndReboot}. If you want to use an apex not preinstalled you can call
+ * {@link #pushApexAndReboot}. After you push one (non-preinstalled) apex, you can update it using
+ * either method.
+ *
+ * <p>In order to revert the apexes that were installed or pushed, call
+ * {@link #revertChanges}. This normally happens from your {@code @AfterClass} method.
+ *
+ * <p>Requirements: the device must support apex updates and have root access via adb.
+ *
+ * <p>Example usage:
+ *
+ * <pre>{@code
+ *
+ *     static private ApexInstallHelper sApexInstallHelper;
+ *
+ *     @BeforeClassWithInfo
+ *     public static void beforeClassWithDevice(TestInformation testInformation)
+ *             throws Exception {
+ *          sApexInstallHelper = new ApexInstallHelper(testInformation);
+ *          sApexInstallHelper.pushApexAndReboot("test_com.android.modules.example.apex");
+ *          // assuming next line matches a preinstalled apex
+ *          sApexInstallHelper.installApexAndReboot("art.apex");
+ *     }
+ *
+ *      @AfterClass
+ *      public static void afterClass() {
+ *          sApexInstallHelper.revertChanges();
+ *      }
+ *
+ *      // add your own @Test methods
+ * }</pre>
+ *
+ * <p>Additionally, the apex files that you want to update or install need to be accessible
+ * to the test:
+ *
+ * <pre>{@code
+ *
+ * java_test_host {
+ *     name: "Example",
+ *     data: [
+ *         ":test_com.android.modules.example",
+ *     ],
+ *     static_libs: [
+ *         "com.android.modules.testing.utils",
+ *     ],
+ * }</pre>
+ *
+ */
+public class ApexInstallHelper {
+    private final TemporaryFolder mTemporaryFolder;
+    private final SystemPreparer mSystemPreparer;
+    private final InstallUtilsHost mInstallUtilsHost;
+    private final DeviceProvider mDeviceProvider;
+    private boolean mCalledSetUp = false;
+
+    public ApexInstallHelper(TestInformation testInformation) {
+        this(testInformation, RebootStrategy.FULL);
+    }
+
+    public ApexInstallHelper(TestInformation testInformation, RebootStrategy rebootStrategy) {
+        mDeviceProvider = testInformation::getDevice;
+        mTemporaryFolder = new TemporaryFolder();
+        mSystemPreparer = new SystemPreparer(mTemporaryFolder, rebootStrategy,
+                /*testRuleDelegate=*/null, mDeviceProvider);
+        mInstallUtilsHost = new InstallUtilsHost(testInformation);
+    }
+
+    private void setUp() throws Exception {
+        if (mCalledSetUp) {
+            return;
+        }
+        mCalledSetUp = true;
+        mTemporaryFolder.create();
+        // mSystemPreparer doesn't expect to be called to setUp
+
+        ITestDevice device = mDeviceProvider.getDevice();
+        if (!device.isAdbRoot()) {
+            device.enableAdbRoot();
+        }
+
+        assertTrue("Device does not support updating APEX",
+                mInstallUtilsHost.isApexUpdateSupported());
+        assertTrue("Device requires root", device.isAdbRoot());
+    }
+
+    /**
+     * Installs an apex (using {@code adb push}) on the device. This can be used to install a new
+     * apex that is not preinstalled in the system image.
+     *
+     * @param apexFilename the filename of the apex to install.
+     */
+    public void pushApexAndReboot(String apexFilename) throws Exception {
+        setUp();
+        File apexFile = mInstallUtilsHost.getTestFile(apexFilename);
+        mSystemPreparer.pushFile(apexFile, "/system/apex/" + apexFilename);
+        mSystemPreparer.reboot();
+    }
+
+    /**
+     * Installs an apex (using {@code adb install}) on the device. This can only be used to
+     * install a newer version of an apex that is already installed on the device (either
+     * preinstalled in the system image or previously installed using
+     * {@link #installApexAndReboot}).
+     *
+     * @param apexFilename the filename of the apex which contains the update.
+     */
+    public void installApexAndReboot(String apexFilename) throws Exception {
+        setUp();
+        File apexFile = mInstallUtilsHost.getTestFile(apexFilename);
+        mDeviceProvider.getDevice().installPackage(apexFile, true);
+        mSystemPreparer.reboot();
+    }
+
+    /**
+     * Calls this method to undo all installs and pushes performed by this helper when your test
+     * has finished.
+     *
+     * <p>This should typically be called from your {@code @AfterClass} method.
+     */
+    public void revertChanges() {
+        if (!mCalledSetUp) {
+            return;
+        }
+        // in line with other tests, clean up system preparer before the temporary folder
+        mSystemPreparer.after();
+        mTemporaryFolder.delete();
+        mCalledSetUp = false;
+    }
+}