How can I unit test Android activity acting on Accelerometer?

Question

I start with an Activity based on this ShakeActivity , and I want to write some unit tests for it. I previously wrote some small tests for Android, but I don’t know where to start. I want to pass several different values ​​to the accelerometer and check how the activity reacts to it. For the moment, I save this simply and simply update the counter variable private int and TextView when the "shake" event occurs.

Therefore, my question largely comes down to the following:

How to send fake data to an accelerometer with unit test?

Answer 1

My solution for this turned out to be simpler than I expected. I do not test the accelerometer as much as I test the reaction of the application to the event raised by the accelerometer, and I just needed to test accordingly. My class implements SensorListener , and I wanted to check what is happening onSensorChanged. The key then was to fuel some values ​​and check the status of my activity. Example:

public void testShake() throws InterruptedException {
    mShaker.onSensorChanged(SensorManager.SENSOR_ACCELEROMETER, new float[] {0, 0, 0} );
    //Required because method only allows one shake per 100ms
    Thread.sleep(500);
    mShaker.onSensorChanged(SensorManager.SENSOR_ACCELEROMETER, new float[] {300, 300, 300});
    Assert.assertTrue("Counter: " + mShaker.shakeCounter, mShaker.shakeCounter > 0);
}

Answer 2

How can I send fake data to the unit test accelerometer?

AFAIK, you cannot.

Ask your shaker logic to use a pluggable data source. In the unit test, put the layout. In production, place a wrapper around the accelerometer.

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Answer 3

, .

interface IAccelerometerReader {
    public float[] readAccelerometer();
}

AndroidAccelerometerReader FakeAccelerometerReader. IAccelerometerReader, Android Fake.

Answer 4

, , - , SensorListener. , SensorEvent , SensorListener.onSensorChanged(SensorEvent event), SensorListener :

public  class ShakeDetector implements SensorEventListener {

     @Override
     public void onSensorChanged(SensorEvent event) {

         float x = event.values[0];
         float y = event.values[1];
         float z = event.values[2];

         onSensorUpdate(x, y, z);
     }

     public void onSensorUpdate(float x, float y, float z) {
         // do my (testable) logic here
     }
}

Then I can call onSensorUpdateddirectly from my test code, which simulates shooting with an accelerometer.

private void simulateShake(final float amplitude, int interval, int duration) throws InterruptedException {
    final SignInFragment.ShakeDetector shaker = getFragment().getShakeSensorForTesting();
    long start = System.currentTimeMillis();

    do {
        getInstrumentation().runOnMainSync(new Runnable() {
            @Override
            public void run() {
                shaker.onSensorUpdate(amplitude, amplitude, amplitude);
            }
        });
        Thread.sleep(interval);
    } while (System.currentTimeMillis() - start < duration);
}

Answer 5

  public  class SensorService implements SensorEventListener {
/**
     * Accelerometer values
     */
    private float accValues[] = new float[3];
     @Override
     public void onSensorChanged(SensorEvent event) {

          if (sensorEvent.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            accValues[0] = sensorEvent.values[0];
            accValues[1] = sensorEvent.values[1];
            accValues[2] = sensorEvent.values[2];
        }

     }
} 

you can test the above code snippet as follows

@Test
    public void testOnSensorChangedForAcceleratorMeter() throws Exception {
        Intent intent=new Intent();
        sensorService.onStartCommand(intent,-1,-1);

        SensorEvent sensorEvent=getEvent();
        Sensor sensor=getSensor(Sensor.TYPE_ACCELEROMETER);
        sensorEvent.sensor=sensor;
        sensorEvent.values[0]=1.2345f;
        sensorEvent.values[1]=2.45f;
        sensorEvent.values[2]=1.6998f;
        sensorService.onSensorChanged(sensorEvent);

        Field field=sensorService.getClass().getDeclaredField("accValues");
        field.setAccessible(true);
        float[] result= (float[]) field.get(sensorService);
        Assert.assertEquals(sensorEvent.values.length,result.length);
        Assert.assertEquals(sensorEvent.values[0],result[0],0.0f);
        Assert.assertEquals(sensorEvent.values[1],result[1],0.0f);
        Assert.assertEquals(sensorEvent.values[2],result[2],0.0f);
    } 




private Sensor getSensor(int type) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException, NoSuchFieldException {
            Constructor<Sensor> constructor = Sensor.class.getDeclaredConstructor(new Class[0]);
            constructor.setAccessible(true);
            Sensor sensor= constructor.newInstance(new Object[0]);

            Field field=sensor.getClass().getDeclaredField("mType");
            field.setAccessible(true);
            field.set(sensor,type);
            return sensor;
        }



private SensorEvent getEvent() throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        Constructor<SensorEvent> constructor = SensorEvent.class.getDeclaredConstructor(int.class);
        constructor.setAccessible(true);
        return constructor.newInstance(new Object[]{3});
    }