class TestMonad(unittest.TestCase):
def setUp(self):
self.world = {'foo': 'bar'}
self.monad = Monad(self.world)
def success(self, result):
return self.monad.success(result)
def failure(self, error):
return self.monad.failure({}, error)
def test_is_initially_successful_on_successful(self):
self.assertEquals(self.success(12).is_success(), True)
def test_is_not_initially_successful_on_failure(self):
self.assertEquals(self.failure('error').is_success(), False)
''' describe success '''
def test_success_preserves_the_world(self):
self.assertEquals(self.success(12).world, self.world)
''' describe failure '''
def test_failure_preserves_the_world(self):
self.assertEquals(self.failure("error").world, self.world)
''' describe on_success '''
def test_on_success_yields_the_block_and_returns_its_result(self):
self.assertEquals(self.success(12).on_success(lambda x: 13), 13)
def test_on_success_doesnt_yields_the_block_on_failure(self):
callback = MagicMock()
self.success(12).on_failure(callback)
callback.assert_not_called()
def test_on_success_should_return_itself_on_failure(self):
f = self.failure("error")
self.assertEquals(f.on_success(lambda x: x), f)
''' describe on_failure '''
def test_on_failure_yields_the_block_and_returns_its_result(self):
self.assertEquals(self.failure("error").on_failure(lambda x: 13), 13)
def test_on_failure_doesnt_yields_the_block_on_success(self):
callback = MagicMock()
self.failure("error").on_success(callback)
callback.assert_not_called()
def test_on_failure_should_return_itself_on_success(self):
f = self.success(12)
self.assertEquals(f.on_failure(lambda x: x), f)
def setUp(self):
self.world = {'foo': 'bar'}
self.monad = Monad(self.world)