Android Espresso onData with doesNotExist

Question

I am trying to verify that a ListView does not contain a particular item. Here\'s the code I\'m using:

onData(allOf(is(instanceOf(Contact.class         


        

Answer 1

According to Espresso samples you must not use onData(...) to check if view doesn't exists in adapter. Check this out - link. Read "Asserting that a data item is not in an adapter" part. You have to use a matcher together with onView() that finds the AdapterView.

Based on Espresso samples from link above:

1. matcher:

   private static Matcher<View> withAdaptedData(final Matcher<Object> dataMatcher) {
       return new TypeSafeMatcher<View>() {
   
           @Override
           public void describeTo(Description description) {
               description.appendText("with class name: ");
               dataMatcher.describeTo(description);
           }
   
           @Override
           public boolean matchesSafely(View view) {
               if (!(view instanceof AdapterView)) {
                   return false;
               }
   
               @SuppressWarnings("rawtypes")
               Adapter adapter = ((AdapterView) view).getAdapter();
               for (int i = 0; i < adapter.getCount(); i++) {
                   if (dataMatcher.matches(adapter.getItem(i))) {
                       return true;
                   }
               }
               return false;
           }
       };
   }
   

2. then onView(...), where R.id.list is the id of your adapter ListView:

   @SuppressWarnings("unchecked")
   public void testDataItemNotInAdapter(){
       onView(withId(R.id.list))
           .check(matches(not(withAdaptedData(is(withContactItemName("TestName"))))));
   }
   

And one more suggestion - to avoid writing is(withContactItemName(is("TestName")) add below code to your matcher:

    public static Matcher<Object> withContactItemName(String itemText) {
        checkArgument( itemText != null );
        return withContactItemName(equalTo(itemText));
    }

then you'll have more readable and clear code is(withContactItemName("TestName")