android instrumentation test case - getinstrumentation() returning null

I've been trying to make a test case extending in开发者_C百科tstrumentationtestcase, and whenever I call getinstrumentation() it returns a null instance of Instrumentation instead of an Instrumentation, rendering any of the automation I'm wanting to do useless. I have the permission set in the manifest as well even though I'm only testing the automation on the same app this case is going to run on...any ideas?

You need inject the instrumentation programmatically by calling injectInstrumentation(InstrumentationRegistry.getInstrumentation()); using InstrumentationRegistry from the official Android testing-support-lib:0.1

I had a similar problem and it seems that the getInstrumentation() method returns a valid instrumentation only after the base class (InstrumentationTestCase) setUp method is called. Please look at the code below and check the LogCat debug messages:

import android.app.Instrumentation;
import android.test.InstrumentationTestCase;
import android.util.Log;

public class TestInstrumentation extends InstrumentationTestCase {

private static final String LOG_TAG = BrowseLocationsTest.class.getSimpleName();

private Instrumentation instr;

public TestInstrumentation() {
    instr = getInstrumentation();
    Log.d(LOG_TAG, "TestInstrumentation instrumentation: " + instr);
}

@Override
protected void setUp() throws Exception {
    instr = getInstrumentation();
    Log.d(LOG_TAG, "setUp instrumentation: " + instr);

    super.setUp();

    instr = getInstrumentation();
    Log.d(LOG_TAG, "setUp instrumentation: " + instr);
}

public void testInstrumentation() {
    Log.d(LOG_TAG, "testInstrumentation instrumentation: " + instr);
}
}

The instrumentation is right in place as expected right after the super.setUp() call.

Had the same problem while using the Testing Support Library with the '@RunWith(AndroidJUnit4.class)' annotation, even though I made sure to inject my instrumentation in the setUp() method as indicated by @Gallal and @Dariusz Gadomski, only it continued to throw NullPointerExceptions.

Turns out, I forgot to include the @Before annotation on my setup method so jUnit4 didn't run it, whereas before with the jUnit3 based Instrumentation tests, it would've run. Since I implemented the instrumentation injection in setUp(), it never got injected even though the code looked like it should have been injecting it.

So instead of

@Override
protected void setUp() throws Exception {
...

Be sure to use

@Before
public void setUp() throws Exception {
    super.setUp();
    injectInstrumentation(InstrumentationRegistry.getInstrumentation());
}

instead.

I think what you really need is Context, in JUnit4, we can get context by InstrumentationRegistry.getContext();