Assert called with argument of specific type

Question

I want to check in my test if a function is called with an argument of a specific class.

class Foo:
... 

I found mock.ANY, but there I cannot pass any class. What is want is:

test_mock.assert_called_with("expected string", ANY(spec=Foo))

Answer 1

I solved it with a custom matcher.

class TypeMatcher:

def __init__(self, expected_type):
    self.expected_type = expected_type

def __eq__(self, other):
    return isinstance(other, self.expected_type)

And then test it like this:

test_mock.assert_called_with("expected string", TypeMatcher(Foo))