def test_custom_class(self):
class A: pass
@assure(isa(A))
def f(x):
return x
a = A()
self.assertEquals(a, f(a))
def test_value_error(self):
class A: pass
@assure(isa(A))
def f(x):
return x
with self.assertRaises(ValueError):
f(1)
def test_in_string(self):
@assure(isa(str))
def f(x):
return x
self.assertEquals("bla", f("bla"))
