1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.test;
18
19import android.app.Application;
20import android.app.Instrumentation;
21import android.content.Context;
22
23/**
24 * This test case provides a framework in which you can test Application classes in
25 * a controlled environment.  It provides basic support for the lifecycle of a
26 * Application, and hooks by which you can inject various dependencies and control
27 * the environment in which your Application is tested.
28 *
29 * <p><b>Lifecycle Support.</b>
30 * Every Application is designed to be accessed within a specific sequence of
31 * method calls (see {@link android.app.Application} for more details).
32 * In order to support the lifecycle of a Application, this test case will make the
33 * following calls at the following times.
34 *
35 * <ul><li>The test case will not call onCreate() until your test calls
36 * {@link #createApplication()}.  This gives you a chance
37 * to set up or adjust any additional framework or test logic before
38 * onCreate().</li>
39 * <li>After your test completes, the test case {@link #tearDown} method is
40 * automatically called, and it will stop & destroy your application by calling its
41 * onDestroy() method.</li>
42 * </ul>
43 *
44 * <p><b>Dependency Injection.</b>
45 * Every Application has one inherent dependency, the {@link android.content.Context Context} in
46 * which it runs.
47 * This framework allows you to inject a modified, mock, or isolated replacement for this
48 * dependencies, and thus perform a true unit test.
49 *
50 * <p>If simply run your tests as-is, your Application will be injected with a fully-functional
51 * Context.
52 * You can create and inject alternative types of Contexts by calling
53 * {@link AndroidTestCase#setContext(Context) setContext()}.  You must do this <i>before</i> calling
54 * {@link #createApplication()}.  The test framework provides a
55 * number of alternatives for Context, including {@link android.test.mock.MockContext MockContext},
56 * {@link android.test.RenamingDelegatingContext RenamingDelegatingContext}, and
57 * {@link android.content.ContextWrapper ContextWrapper}.
58 */
59public abstract class ApplicationTestCase<T extends Application> extends AndroidTestCase {
60
61    Class<T> mApplicationClass;
62
63    private Context mSystemContext;
64
65    public ApplicationTestCase(Class<T> applicationClass) {
66        mApplicationClass = applicationClass;
67    }
68
69    private T mApplication;
70    private boolean mAttached = false;
71    private boolean mCreated = false;
72
73    /**
74     * @return Returns the actual Application under test.
75     */
76    public T getApplication() {
77        return mApplication;
78    }
79
80    /**
81     * This will do the work to instantiate the Application under test.  After this, your test
82     * code must also start and stop the Application.
83     */
84    @Override
85    protected void setUp() throws Exception {
86        super.setUp();
87
88        // get the real context, before the individual tests have a chance to muck with it
89        mSystemContext = getContext();
90    }
91
92    /**
93     * Load and attach the application under test.
94     */
95    private void setupApplication() {
96        mApplication = null;
97        try {
98            mApplication = (T) Instrumentation.newApplication(mApplicationClass, getContext());
99        } catch (Exception e) {
100            assertNotNull(mApplication);
101        }
102        mAttached = true;
103    }
104
105    /**
106     * Start the Application under test, in the same way as if it was started by the system.
107     * If you use this method to start the Application, it will automatically
108     * be stopped by {@link #tearDown}.  If you wish to inject a specialized Context for your
109     * test, by calling {@link AndroidTestCase#setContext(Context) setContext()},
110     * you must do so  before calling this method.
111     */
112    final protected void createApplication() {
113        assertFalse(mCreated);
114
115        if (!mAttached) {
116            setupApplication();
117        }
118        assertNotNull(mApplication);
119
120        mApplication.onCreate();
121        mCreated = true;
122    }
123
124    /**
125     * This will make the necessary calls to terminate the Application under test (it will
126     * call onTerminate().  Ordinarily this will be called automatically (by {@link #tearDown}, but
127     * you can call it directly from your test in order to check for proper shutdown behaviors.
128     */
129    final protected void terminateApplication() {
130        if (mCreated) {
131            mApplication.onTerminate();
132        }
133    }
134
135    /**
136     * Shuts down the Application under test.  Also makes sure all resources are cleaned up and
137     * garbage collected before moving on to the next
138     * test.  Subclasses that override this method should make sure they call super.tearDown()
139     * at the end of the overriding method.
140     *
141     * @throws Exception
142     */
143    @Override
144    protected void tearDown() throws Exception {
145        terminateApplication();
146        mApplication = null;
147
148        // Scrub out members - protects against memory leaks in the case where someone
149        // creates a non-static inner class (thus referencing the test case) and gives it to
150        // someone else to hold onto
151        scrubClass(ApplicationTestCase.class);
152
153        super.tearDown();
154    }
155
156    /**
157     * Return a real (not mocked or instrumented) system Context that can be used when generating
158     * Mock or other Context objects for your Application under test.
159     *
160     * @return Returns a reference to a normal Context.
161     */
162    public Context getSystemContext() {
163        return mSystemContext;
164    }
165
166    /**
167     * This test simply confirms that the Application class can be instantiated properly.
168     *
169     * @throws Exception
170     */
171    final public void testApplicationTestCaseSetUpProperly() throws Exception {
172        setupApplication();
173        assertNotNull("Application class could not be instantiated successfully", mApplication);
174    }
175}
176