unit testing custom view

[WeyenDrote]

For an application I am developing I subclassed RelativeLayout to
create a custom view, which I would like to test with Robolectric.

public class MyView extends RelativeLayout
{
public MyView (Context context, AttributeSet attrs)
{
super(context, attrs);

LayoutInflater mInflater = (LayoutInflater)
context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
RelativeLayout mBarView = (RelativeLayout)
mInflater.inflate(R.layout.myview, null);
addView(mBarView);
}
}

The layout itself is a simple RelativeLayout containing LinearLayouts
with ImageButtons. I want to write a unittest to check that the
ImageButtons change resource when something happens. The following is
a test for the initial state:

@Test
public void shouldSetIconAOnButtonA()
{
MyView myView = new MyView(null, null);
ImageButton buttonA = (ImageButton)
myView.findViewById(R.id.buttonA);
ShadowImageView shadowImageView = Robolectric.shadowOf(buttonA);
assertThat(shadowImageView.getResourceId(),
equalTo(R.drawable.iconA));
}

While the code works in the application and the view is rendered
correctly, the unittest fails with a nullpointerexception; not
surprising as I pass null in the constructor. The question is: can
Robolectric perform these tests or help me pass a fake Context and
AttributeSet? Or should I load this view in a dummy Activity to get it
to test?

[Tyler Schultz]

Hi, I just wrote a blog post that explains how I like to test custom views:

https://pivotallabs.com/users/tyler/blog/articles/1744-android-unit-testing-custom-views

I find specifying layout in java frustrating.  I prefer to create my views in xml, and put only the behavior in the java class. 

--Tyler