def test_eq(self):
# Arrange
s1 = mbe.Something(10)
s2 = mbe.Something(10)
s3 = mbe.Something(11)
n1 = mbe.Nothing(10)
# Act
# Assert
self.assertTrue(s1 == s2)
self.assertFalse(s1 == s3)
self.assertFalse(s1 == n1)
def test_lift_WhenLiftedFunctionRaisesException_NothingIsReturn(self):
# Arrange
def triple(x):
return 3 / x
lifted_f = mbe.Maybe.lift(triple)
arg = mbe.Something(0)
expected = mbe.Nothing()
# Act
result = lifted_f(arg)
# Assert
self.assertEqual(result, expected)
def test_lift_WhenLiftedFunctionCalledOnNothing_FailureIsNothing(self):
# Arrange
def triple(x):
return 3 * x
lifted_f = mbe.Maybe.lift(triple)
arg = mbe.Nothing()
expected = mbe.Nothing()
# Act
result = lifted_f(arg)
# Assert
self.assertEqual(result, expected)
def test_liftn_WhenImproperNumberOfArgumentsGiven_NothingIsReturned(self):
# Arrange
def sumThree(x, y, z):
return x + y + z
lifted_f = mbe.Maybe.liftn(sumThree)
arg1 = mbe.Something(1)
arg2 = mbe.Something(2)
# Act
result = lifted_f(arg1, arg2)
expected = mbe.Nothing()
# Assert
self.assertEqual(result, expected)
def test_liftn_WhenNotCallableIsGiven_NothingIsReturned(self):
# Arrange
def sumThree(x, y, z):
return x + y / z
lifted_f = mbe.Maybe.liftn(sumThree)
arg1 = mbe.Something(1)
arg2 = mbe.Something(2)
# Act
result = lifted_f(arg1, arg2)
expected = mbe.Nothing()
# Assert
self.assertEqual(result, expected)
def test_lift_WhenLiftedFunctionCalledOnSomething_SomethingIsReturned(
self):
# Arrange
def triple(x):
return 3 * x
lifted_f = mbe.Maybe.lift(triple)
arg = mbe.Something(5)
expected = mbe.Something(15)
# Act
result = lifted_f(arg)
# Assert
self.assertEqual(result, expected)
def test_liftn_WhenLiftedFunctionRaisesException_NothingIsReturn(self):
# Arrange
def sumThree(x, y, z):
return x + y / z
lifted_f = mbe.Maybe.liftn(sumThree)
arg1 = mbe.Something(1)
arg2 = mbe.Something(2)
arg3 = mbe.Something(0)
# Act
result = lifted_f(arg1, arg2, arg3)
expected = mbe.Nothing()
# Assert
self.assertEqual(result, expected)
def test_liftn_WhenLiftedFunctionCalledOnNothing_NothingIsReturn(self):
# Arrange
def sumThree(x, y, z):
return x + y + z
lifted_f = mbe.Maybe.liftn(sumThree)
arg1 = mbe.Something(1)
arg2 = mbe.Nothing(4)
arg3 = mbe.Something(3)
# Act
result = lifted_f(arg1, arg2, arg3)
expected = mbe.Nothing()
# Assert
self.assertEqual(result, expected)
def test_unit(self):
# Arrange
expected = mbe.Nothing()
# Act
result = mbe.Nothing.unit("error")
# Assert
self.assertEqual(result, expected)
def test_unit(self):
# Arrange
expected = mbe.Something(123)
# Act
result = mbe.Something.unit(123)
# Assert
self.assertEqual(result, expected)
def test_liftn_WhenOneArgumentFunctionIsGiven_liftIsReproduced(self):
# Arrange
def double(x):
return 2 * x
lifted_fn = mbe.Maybe.liftn(double)
lifted_f = mbe.Maybe.lift(double)
arg = mbe.Something(5)
# Act
result_f = lifted_f(arg)
result_fn = lifted_fn(arg)
# Assert
self.assertEqual(result_f, result_fn)
def test_isSomething_isNothing(self):
nothing = mbe.Nothing()
self.assertFalse(nothing.isSomething)
self.assertTrue(nothing.isNothing)
def test_isSomething_isNothing(self):
something = mbe.Something(123)
self.assertTrue(something.isSomething)
self.assertFalse(something.isNothing)