@Test
public void createCoalesceExpression_ObjectAndStringOperands_ReturnClassIsString() {
Class<?> expectedClass = Object.class;
Object left = new Object();
Object right = "1";
Expression e = coalesce(left, right);
assertThat(e.getResultClass(), is(assignableTo(expectedClass)));
}
@Test
public void createCoalesceExpression_NullAndObjectOperands_ReturnClassIsString() {
Class<?> expectedClass = String.class;
Object left = null;
Object right = new String();
Expression e = coalesce(left, right);
assertThat(e.getResultClass(), is(assignableTo(expectedClass)));
}