text: # Copyright (C) 2016 Allen Li
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  """Test data constructors."""
  
  import pytest
  
  import mir.monads.data as data
  
  
  class UnaryConstructor(metaclass=data.Constructor):
      arity = 1
  
  
  def test_invalid_arguments():
      with pytest.raises(TypeError):
          UnaryConstructor()
  
  
  def test_eq():
      assert UnaryConstructor(1) == UnaryConstructor(1)
  
  
  def test_not_eq_value():
      assert UnaryConstructor(1) != UnaryConstructor(2)
  
  
  def test_not_eq_tuple():
      assert UnaryConstructor(1) != (1,)
  
  
  def test_no_slots():
      x = UnaryConstructor(1)
      with pytest.raises(AttributeError):
          x.foo = 1
  