Forgetting to balance the Parcelable read/write calls can lead to inconsistent state. Here's some helper code for testing objects that implement Parcelable...

Parcelable testing strategy

public void testParcelableThing() throws Exception {
	// sample usage
	MyParcelableThing parcelable = getTheThing();
	
	Parcel parcel = Parcel.obtain();
	parcelable.writeToParcel(parcel, 0); 
	parcel.setDataPosition(0);
	
	MyParcelableThing unparcelled = new MyParcelableThing(parcel);
	
	parcel.recycle();
		
	// here's the trick - assuming your Parcelable object has getters for its props
	assertGettersEqual(parcelable, unparcelled);
}


// helper methods

public List<Method> getGetterMethodList(Object obj) {
	List<Method> methods = Arrays.asList(obj.getClass().getDeclaredMethods());
	List<Method> getters = new ArrayList<Method>();
	for (Method m : methods) {
	    String name = m.getName();
	    if (name.startsWith("get") || name.startsWith("is")) {
	    	getters.add(m);
	    }
	}
	return getters;
}
	
public boolean assertGettersEqual(Object obj1, Object obj2) {
	Class<?> obj2Class = obj2.getClass();
	List<Method> getters = getGetterMethodList(obj1);
	for (Method method : getters) {
		Method method2;
		try {
			method2 = obj2Class.getDeclaredMethod(method.getName());
			Object result1 = method.invoke(obj1);
			Object result2 = method2.invoke(obj2);
			boolean isEqual = true;
			if((result1==null&&result2!=null || result1!=null&&result2==null) && result1!=null&&result2!=null) {
				isEqual = false;
			} else if(result1!=result2 && !result1.equals(result2)){
				isEqual = false;
			}
			if(!isEqual) {
				fail("getters not equal for: " + method.getName() + " expected: " + result1 + "\n but got\n " + result2);
				return false;
			}
		} catch (Exception e) {
			fail("Problem with reflection (does getter exist?): " + method.getName() + " reason: " + e);
			return false;
		}
	}
	return true;
}