From Newsgroup: comp.lang.python
Is it possible to mock out a function in a process started with multiprocessing.Process? AI tells me it is, but I have not gotten it to
work.
The use case is that I have a server I want to write tests for. I want the tests to start up the server, but I need to mock out the JWT based auth functions in the server.
If it is possible, perhaps I am doing something wrong.
The function I want to mock out is in foo.bar.baz.validate_jwt`.
The server imports it as from .baz import validate_jwt. I have tried to
mock it many ways, here is the latest attempt:
@pytest.fixture(scope="module")
def mock_get_public_key():
return PUBLIC_KEY
@patch('foo.bar.baz.validate_jwt')
def test_fn(mock_validate_jwt, mock_get_public_key):
I also tried `@patch('foo.bar.main.validate_jwt')`
But no matter what I tried the real functions get called.
Here is an example:
In directory foo/bar file baz.py
def get_public_key(token: str) -> str:
print("in get_public_key)
def validate_jwt(token: str) -> dict
public_key = get_public_key(token)
print("in validate_jwt)
In directory foo/bar file main.py:
from .baz import validate_jwt
def server(token):
valid = validate_jwt(token)
In my test code, which is in test/test_main.py (test and foo are at the
same level)
@pytest.fixture(scope="module")def mock_get_public_key():
return PUBLIC_KEY
def run_server(port):
from foo.bar.main import start
start(is_prod=False, port=port)
@pytest.fixture(scope="module")def mock_validate_jwt(token):
return {"user": "test_user"}
@pytest.fixture(scope="module")def start_server():
port = 8002
server_process = multiprocessing.Process(target=run_server, args=(port,))
server_process.start()
max_retries = 10
for i in range(max_retries):
try:
response = requests.get(f"
http://127.0.0.1:{port}/echo?message=test")
if response.status_code == 200:
break
except requests.ConnectionError:
time.sleep(1)
else:
pytest.fail("Server did not start in time") @pytest.mark.usefixtures("start_server")@patch('dispatcher.main.validate_jwt')def
test_function(mock_validate_jwt, mock_get_public_key):
,
.
.
When test_function runs the real validate_jwt runs, not my mock.
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