Add hosttestlib library.

hosttestlib is a simple JUnit extension framework for tests that need to interact externally (ie
from a host machine) with an Android device.

tools/hosttestlib/src/com/android/hosttest/DeviceTestCase.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2009 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.hosttest;
+
+import com.android.ddmlib.IDevice;
+
+import junit.framework.TestCase;
+
+/**
+ * Helper JUnit test case that stores reference to an Android device and test data.
+ *
+ * Can be extended to verify an Android device's response to various adb commands.
+ */
+public abstract class DeviceTestCase extends TestCase implements DeviceTest {
+
+    /** Android device under test */
+    private IDevice mDevice = null;
+    /** optionally, used to store path to test data files */
+    private String mTestDataPath = null;
+
+    protected DeviceTestCase() {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void setDevice(IDevice device) {
+        mDevice = device;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public IDevice getDevice() {
+        return mDevice;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public String getTestAppPath() {
+        return mTestDataPath;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void setTestAppPath(String path) {
+        mTestDataPath = path;
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+        // ensure device has been set before test is run
+        assertNotNull(getDevice());
+    }
+}