ShadowPreference doesn't implement getContext()

[ZacSweers]

Real Preferences have a getContext() method, but the current ShadowPreference implementation currently doesn't. This breaks verifying custom styleable attributes on custom preference objects.

[erd]

Methods that aren't shadowed simply call through to the underlying android object. If anything, ShadowPreference might need a constructor that calls the underlying Preference constructor. Could you provide some code that demonstrates the error you are seeing?

[ZacSweers]

Sure. I have an annotation processing library that generates boilerplate TypedArray stuff for custom styleable attributes.

An example of it in use

Corresponding Robolectric test

The generated code looks like this:

public class CustomPreference$$Barbershop<T extends io.sweers.barber.sample.testing.CustomPreference> implements Barber.IBarbershop<T> {
  protected WeakHashSet lastStyledTargets = new WeakHashSet();

  @Override
  public void style(final T target, final AttributeSet set, final int[] attrs, final int defStyleAttr, final int defStyleRes) {
    this.lastStyledTargets.add(target);
    if (set == null) {
      return;
    }
    TypedArray a = target.getContext().obtainStyledAttributes(set, attrs, defStyleAttr, defStyleRes);
    // Retrieve custom attributes
    if (a.hasValue(0)) {
      target.titleColor = a.getColor(0, -1);
    }
    if (a.hasValue(1)) {
      target.summaryColor = a.getColor(1, -1);
    }
    a.recycle();
  }

  protected boolean hasStyled(final T target) {
    return this.lastStyledTargets.contains(target);
  }
}

The problem occurs via NPE on this line:

TypedArray a = target.getContext().obtainStyledAttributes(set, attrs, defStyleAttr, defStyleRes);

Because target.getContext() returns null. I thought this is because Robolectric is unable to find this method for some reason, but maybe it's just because getContext() itself is returning null. I assumed it was because it wasn't implemented, but I understand now that I misinterpreted how ShadowPreference worked.

Let me know if you need any other info!

[xian]

Robolectric 4.0 fixes many longstanding issues; could you check to see if this remains a problem?

If so, please feel free to reopen this issue and include a link to a public git repo demonstrating the problem to help us diagnose. Thank you!