python assertRaises 不通过带参数函数的测试

Question

assertRaises 使用以下代码给出断言错误。我做错了什么吗？

class File_too_small(Exception):
    "Check file size"

def foo(a,b):
    if a<b:
        raise File_too_small
class some_Test(unittest.TestCase):

    def test_foo(self):
        self.assertRaises(File_too_small,foo(1,2))

测试似乎通过了以下修改

def foo:
    raise File_too_small

def test_foo(self):
    self.assertRaises(File_too_small,foo)

Answer 1

像这样尝试:

def test_foo(self):
    with self.assertRaises(File_too_small):
        foo(1, 2)

或:

def test_foo(self):
    self.assertRaises(File_too_small, foo, 1, 2):