Learning from Code Coverage

• StringFunction coverage

• Null is never passed to this method. This should be tested.

• Or could we just eliminate the check; what happens if null is passed? Write a couple of tests and find out:

      public void testStringValueOfNull() {
          assertEquals("", StringFunction.evaluate(null, null));
      }
      
      public void testStringValueOfNullWithNonNullNavigator() {
          assertEquals("", StringFunction.evaluate(null, new DocumentNavigator()));
      }

• Which objects are frequently passed to this method, and could those be tested for first?