如何使用内容解析器/提供者测试类？

Question

我正在尝试测试查询内容解析器的类。

我想使用 MockContentResolver 和模拟 query 方法。

问题是这个方法是最终的。我应该怎么办？使用模拟框架？模拟其他类？提前致谢。

public class CustomClass {

    private ContentResolver mContentResolver;

    public CustomClass(ContentResolver contentResolver) {
        mContentResolver = contentResolver;
    }

    public String getConfig(String key) throws NoSuchFieldException {
        String value = null;

            Cursor cursor = getContentResolver().query(...);
            if (cursor.moveToFirst()) {
                //...
            }
        //..
    }
}

Answer 1

下面是一个使用 getContentResolver().query 从内容提供者返回模拟数据的示例测试。

它应该适用于任何内容提供程序，只需进行一些修改，但此示例模拟从联系人内容提供程序返回电话号码

以下是一般步骤：

1. 使用 MatrixCursor 创建适当的光标
2. 扩展 MockContentProvider 以返回创建的光标
3. 将提供程序添加到 MockContentResolver 使用addProvider 和 setContentResolver
4. 将 MockContentResolver 添加到扩展的 MockContext
5. 将上下文传递到被测试的类

因为 query 是一个最终方法，所以您不仅需要模拟MockContentProvider 也是 MockContentResolver。否则，在查询方法期间调用 acquireProvider 时会出现错误。

下面是示例代码：

public class MockContentProviderTest extends AndroidTestCase{
    public void testMockPhoneNumbersFromContacts(){
        //Step 1: Create data you want to return and put it into a matrix cursor
        //In this case I am mocking getting phone numbers from Contacts Provider
        String[] exampleData = {"(979) 267-8509"}; 
        String[] examleProjection = new String[] { ContactsContract.CommonDataKinds.Phone.NUMBER};
        MatrixCursor matrixCursor = new MatrixCursor(examleProjection);
        matrixCursor.addRow(exampleData);

        //Step 2: Create a stub content provider and add the matrix cursor as the expected result of the query
        HashMapMockContentProvider mockProvider = new HashMapMockContentProvider();
        mockProvider.addQueryResult(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, matrixCursor);

        //Step 3: Create a mock resolver and add the content provider.
        MockContentResolver mockResolver = new MockContentResolver();
        mockResolver.addProvider(ContactsContract.AUTHORITY /*Needs to be the same as the authority of the provider you are mocking */, mockProvider);

        //Step 4: Add the mock resolver to the mock context
        ContextWithMockContentResolver mockContext = new ContextWithMockContentResolver(super.getContext());
        mockContext.setContentResolver(mockResolver);

        //Example Test 
        ExampleClassUnderTest underTest = new ExampleClassUnderTest();
        String result = underTest.getPhoneNumbers(mockContext);
        assertEquals("(979) 267-8509",result);
    }

    //Specialized Mock Content provider for step 2.  Uses a hashmap to return data dependent on the uri in the query
     public class HashMapMockContentProvider extends MockContentProvider{
         private HashMap<Uri, Cursor> expectedResults = new HashMap<Uri, Cursor>();
         public void addQueryResult(Uri uriIn, Cursor expectedResult){
             expectedResults.put(uriIn, expectedResult);
         }
         @Override
         public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder){
                return expectedResults.get(uri);
         } 
     }

     public class ContextWithMockContentResolver extends RenamingDelegatingContext {
            private ContentResolver contentResolver;
            public void setContentResolver(ContentResolver contentResolver){ this.contentResolver = contentResolver;}
            public ContextWithMockContentResolver(Context targetContext) { super(targetContext, "test");}
            @Override public ContentResolver getContentResolver() { return contentResolver; }
            @Override public Context getApplicationContext(){ return this; } //Added in-case my class called getApplicationContext() 
     }

     //An example class under test which queries the populated cursor to get the expected phone number 
     public class ExampleClassUnderTest{
         public  String getPhoneNumbers(Context context){//Query for  phone numbers from contacts
                String[] projection = new String[]{ ContactsContract.CommonDataKinds.Phone.NUMBER};
                Cursor cursor= context.getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, projection, null, null, null);
                cursor.moveToNext();
                return cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
         }
     }
}

如果您不想传入上下文：

如果您想让类中的 getContext() 返回它在测试中而不是传递它，你应该能够像这样在你的 android 测试中重写 getContext()

@Override
 public Context getContext(){
    return new ContextWithMockContentResolver(super.getContext());   
 } 

Answer 2

这个问题已经很老了，但人们可能仍然会像我一样面临这个问题，因为没有太多关于测试这个问题的文档。

对我来说，为了测试依赖于内容提供者（来自android API）的类，我使用了ProviderTestCase2，

public class ContactsUtilityTest extends ProviderTestCase2<OneQueryMockContentProvider> {


private ContactsUtility contactsUtility;

public ContactsUtilityTest() {
    super(OneQueryMockContentProvider.class, ContactsContract.AUTHORITY);
}


@Override
protected void setUp() throws Exception {
    super.setUp();
    this.contactsUtility = new ContactsUtility(this.getMockContext());
}

public void testsmt() {
    String phoneNumber = "777777777";

    String[] exampleData = {phoneNumber};
    String[] examleProjection = new String[]{ContactsContract.PhoneLookup.NUMBER};
    MatrixCursor matrixCursor = new MatrixCursor(examleProjection);
    matrixCursor.addRow(exampleData);

    this.getProvider().addQueryResult(matrixCursor);

    boolean result = this.contactsUtility.contactBookContainsContact(phoneNumber);
    // internally class under test use this.context.getContentResolver().query(); URI is ContactsContract.PhoneLookup.CONTENT_FILTER_URI
    assertTrue(result);
}


}


public class OneQueryMockContentProvider extends MockContentProvider {
private Cursor queryResult;

public void addQueryResult(Cursor expectedResult) {
    this.queryResult = expectedResult;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
    return this.queryResult;
}
}

它是使用Jenn Weingarten的答案编写的。
有几点需要注意：
-您的MockContentProvider必须是公开的
-您必须在测试类中使用 this.getMockContext() 方法中的 Context 而不是 this.getContext()，否则您将访问不是模拟数据，而是来自设备的真实数据（在本例中为联系人）
- 测试不得使用 AndroidJUnit4 运行程序运行
- 测试当然必须作为 Android 仪器测试运行
- 测试构造函数中的第二个参数（权威）必须与被测类中查询的 URI 相同
- 模拟提供程序的类型必须作为类参数提供

基本上 ProviderTestCase2 可以帮助您初始化模拟上下文、模拟内容解析器和模拟内容提供程序。

我发现使用旧的测试方法比尝试使用mockito和junit4为高度依赖于android api的类编写本地单元测试要容易得多。

Answer 3

下面是一个关于如何使用 mockk 库和 Kotlin 存根 ContentResolver 的示例。

注意：如果您在模拟器中运行此测试，此测试似乎不起作用，在具有 API 23 的模拟器中失败，并出现此错误 “java.lang.ClassCastException：android.database.MatrixCursor 无法转换为 java.lang。布尔值”。

澄清了这一点，让我们这样做。具有来自 Context 对象的扩展，即 val Context.googleCalendars: List>，此扩展会过滤日历，日历名称不以“@google.google.com”结尾。 com”，我正在使用此 AndroidTest 测试此扩展的正确行为。

是的，您可以从此处下载存储库。

@Test
    fun getGoogleCalendarsTest() {

        // mocking the context
        val mockedContext: Context = mockk(relaxed = true)

        // mocking the content resolver
        val mockedContentResolver: ContentResolver = mockk(relaxed = true)

        val columns: Array<String> = arrayOf(
            CalendarContract.Calendars._ID,
            CalendarContract.Calendars.NAME
        )

        // response to be stubbed, this will help to stub
        // a response from a query in the mocked ContentResolver
        val matrixCursor: Cursor = MatrixCursor(columns).apply {

            this.addRow(arrayOf(1, "[email protected]"))
            this.addRow(arrayOf(2, "name02")) // this row must be filtered by the extension.
            this.addRow(arrayOf(3, "[email protected]"))
        }

        // stubbing content resolver in the mocked context.
        every { mockedContext.contentResolver } returns mockedContentResolver

        // stubbing the query.
        every { mockedContentResolver.query(CalendarContract.Calendars.CONTENT_URI, any(), any(), any(), any()) } returns matrixCursor

        val result: List<Pair<Long, String>> = mockedContext.googleCalendars

        // since googleCalendars extension returns only the calendar name that ends with @gmail.com
        // one row is filtered from the mocked response of the content resolver.
        assertThat(result.isNotEmpty(), Matchers.`is`(true))
        assertThat(result.size, Matchers.`is`(2))
    }

Answer 4

阅读文档后，我能够编写 MockContentProvider 来实现适当游标的返回。然后我使用 addProvider 将此提供程序添加到 MockContentResolver 中。

Answer 5

我还没有使用过 Mockito，但对于内容提供商来说，您可以依赖 Robolectric。 https://github.com/juanmendez/jm_android_dev/blob/master/16.observers/00.magazineAppWithRx/app/src/test/java/ContentProviderTest.java