def test_composes_functions_from_right_to_left(self):
a = lambda next: lambda x: next(x + 'a')
b = lambda next: lambda x: next(x + 'b')
c = lambda next: lambda x: next(x + 'c')
final = lambda x: x
self.assertEqual(compose(a, b, c)(final)(''), 'abc')
self.assertEqual(compose(b, c, a)(final)(''), 'bca')
self.assertEqual(compose(c, a, b)(final)(''), 'cab')
def test_composes_functions_from_right_to_left(self):
a = lambda next: lambda x: next(x + 'a')
b = lambda next: lambda x: next(x + 'b')
c = lambda next: lambda x: next(x + 'c')
final = lambda x: x
self.assertEqual(compose(a, b, c)(final)(''), 'abc')
self.assertEqual(compose(b, c, a)(final)(''), 'bca')
self.assertEqual(compose(c, a, b)(final)(''), 'cab')
def test_composes_from_right_to_left(self):
double = lambda x: x * 2
square = lambda x: x * x
self.assertEqual(compose(square)(5), 25)
self.assertEqual(compose(square, double)(5), 100)
self.assertEqual(compose(double, square, double)(5), 200)
def test_returns_first_function_if_only_one(self):
func = lambda: {}
self.assertEqual(compose(func), func)
def test_returns_first_given_argument_if_no_given_functions(self):
self.assertEqual(compose()(1,2), 1)
self.assertEqual(compose()(3), 3)
self.assertEqual(compose()(), None)
def test_can_be_seeded_with_multiple_arguments(self):
square = lambda x: x * x
add = lambda x, y: x + y
self.assertEqual(compose(square, add)(1, 2), 9)
def test_composes_from_right_to_left(self):
double = lambda x: x * 2
square = lambda x: x * x
self.assertEqual(compose(square)(5), 25)
self.assertEqual(compose(square, double)(5), 100)
self.assertEqual(compose(double, square, double)(5), 200)
def test_returns_first_function_if_only_one(self):
func = lambda: {}
self.assertEqual(compose(func), func)
def test_returns_first_given_argument_if_no_given_functions(self):
self.assertEqual(compose()(1, 2), 1)
self.assertEqual(compose()(3), 3)
self.assertEqual(compose()(), None)
def test_can_be_seeded_with_multiple_arguments(self):
square = lambda x: x * x
add = lambda x, y: x + y
self.assertEqual(compose(square, add)(1, 2), 9)