public void Delete_Removes_Field()
{
var fieldId = 1;
var deletedField = new Field(fieldId, "First field");
var fieldList = new List <Field>()
{
deletedField,
new Field(2, "Second field")
};
fieldRepo.GetById(fieldId).Returns(deletedField);
fieldRepo.When(d => d.Delete(deletedField))
.Do(d => fieldList.Remove(deletedField));
fieldRepo.GetAll().Returns(fieldList);
var result = underTest.Delete(fieldId);
Assert.DoesNotContain(deletedField, result);
}