How to get Context for Unit Test

Issue

I'm trying to pass the context into a constructor for a unit test. And I'm getting the following error

java.lang.IllegalStateException: No instrumentation registered! Must run under a registering instrumentation.

I've tried the following code.

public class Handler {

    @Mock
    MyViewModel viewModel;

    @Before
    public void setup() {
        Context context = InstrumentationRegistry.getInstrumentation().getContext();
        Handler = new Handler(context, viewModel);

    }
}

Solution

Add @RunWith annotation with AndroidJUnit runner.

@RunWith(AndroidJunit4::class)
public class Handler {

    @Mock
    MyViewModel viewModel;

    @Before
    public void setup() {
        Context context = InstrumentationRegistry.getInstrumentation().getContext();
        Handler = new Handler(context, viewModel);

    }
}

Also add the following dependency if its not addded in the build.gradle(app)

androidTestImplementation 'androidx.test.ext:junit:1.0.0'

Answered By - Rahul Singhal