Content Provider

Content Provider Testing API

---

The main focus of the provider testing API is to provide an isolated testing environment. This ensures that tests always run against data dependencies set explicitly in the test case. It also prevents tests from modifying actual user data. For example, you want to avoid writing a test that fails because there was data left over from a previous test, and you want to avoid adding or deleting contact information in a actual provider.
The test case class and mock object classes for provider testing set up this isolated testing environment for you.

ProviderTestCase2

You test a provider with a subclass of ProviderTestCase2. This base class extends AndroidTestCase, so it provides the JUnit testing framework as well as Android-specific methods for testing application permissions. The most important feature of this class is its initialization, which creates the isolated test environment.
The initialization is done in the constructor for ProviderTestCase2, which subclasses call in their own constructors. The ProviderTestCase2 constructor creates an IsolatedContext object that allows file and database operations but stubs out other interactions with the Android system. The file and database operations themselves take place in a directory that is local to the device or emulator and has a special prefix.
The constructor then creates a MockContentResolver to use as the resolver for the test. The MockContentResolver class is described in detail in the section Mock object classes.
Lastly, the constructor creates an instance of the provider under test. This is a normal ContentProvider object, but it takes all of its environment information from the IsolatedContext, so it is restricted to working in the isolated test environment. All of the tests done in the test case class run against this isolated object.