How to test class using content resolver/provider?

Question

I'm trying to test class that queries content resolver.

I would like to use MockContentResolver and mock query method.

The problem is that this method is final. What should I do? Use mocking framework? Mock other class? Thanks in advance.

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

This question is pretty old but people might still face the issue like me, because there is not a lot of documentation on testing this.

For me, for testing class which was dependent on content provider (from android API) I used 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;
}
}

It's written by using Jenn Weingarten's answer. Few things to note: -your MockContentProvider must be public -you must use Context from method this.getMockContext() instead of this.getContext() in your class under test, otherwise you will access not mock data but real data from device (in this case - contacts) -Test must not be run with AndroidJUnit4 runner -Test of course must be run as android instrumented test -Second parameter in constructor of the test (authority) must be same compared to URI queried in class under test -Type of mock provider must be provided as class parameter

Basically ProviderTestCase2 makes for you initializing mock context, mock content resolver and mock content provider.

I found it much more easier to use older method of testing instead of trying to write local unit test with mockito and junit4 for class which is highly dependent on android api.