How to test the process that a client of an Android bound service bind to the service?

Question

I have an service App that defined a bound service, and another client App that one of its activity binds to the bound service. How can I write test case to test the bind service process?

The code of the client App binding to the service is similar to what the Android official doc has:

public class BindingActivity extends Activity {
    LocalService mService;
    boolean mBound = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    @Override
    protected void onStart() {
        super.onStart();
        // Bind to LocalService
        Intent intent = new Intent();
        intent.setComponent(new ComponentName(SERVICE_APP_PACKAGE_NAME, 
 SERVICE_NAME));
        bindService(intent, connection, Context.BIND_AUTO_CREATE);
    }

    @Override
    protected void onStop() {
        super.onStop();
        unbindService(connection);
        mBound = false;
    }

    /** Called when a button is clicked (the button in the layout file attaches to
      * this method with the android:onClick attribute) */
    public void onButtonClick(View v) {
        if (mBound) {
            // Call a method from the LocalService.
            // However, if this call were something that might hang, then this request should
            // occur in a separate thread to avoid slowing down the activity performance.
            int num = mService.getRandomNumber();
            Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show();
        }
    }

    /** Defines callbacks for service binding, passed to bindService() */
    private ServiceConnection connection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName className,
                IBinder service) {
            // We've bound to LocalService, cast the IBinder and get LocalService instance
            LocalBinder binder = (LocalBinder) service;
            mService = binder.getService();
            mBound = true;
        }

        @Override
        public void onServiceDisconnected(ComponentName arg0) {
            mBound = false;
        }
    };
}

What kind of test case can test the setIntent() & bindService() or unbindService() method in the activity's onStart() and onStop() method?

Answer 1

You don't want to test onBind. You know that works, that's tested as part of the Google framework. What you want to test is two things:

1)That your ServiceConnection functions properly set mBound and mService.

2)That your onStart calls onBind to bind it.

The best way to do this is actually a refactor. This code isn't as testable as it could be. Bring mService and mBound into the ServiceConnection class, and make it a full class (rather than an anonymous class). Then you can easily test (1) using mocks for the input. To test (2) I would actually subclass the Activity, override bindService to just set a variable to true, and ensure after calling onStart the variable was set to true.