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pytest fixture runs for class instead of each tests separately

Could you explain to me please why fixture with scope function(which is supposed to run anew for each test) runs for the whole test class?
#pytest.fixture(scope="function")
def application_with_assigned_task_id(api, db, application_with_tasks_id, set_user_with_st_types):
with allure.step("ищу задание по по id заявки"):
task = \
api.grpc.express_shipping.list_tasks(page_size=100, page_number=1, eams_id=application_with_tasks_id)[
'tasks'][
0]
task_id = task["id"]
with allure.step("назначаю задания на пользователя"):
db.rezon.upd_user_warehouse(set_user_with_st_types, 172873)
db.rezon.storetask_upd_user(task_id, set_user_with_st_types)
with allure.step("проверяю назначение задания"):
res = api.grpc.express_shipping.get_task(id=int(task_id))
assert res["storekeeper"] == db.rezon.get_rezon_user_full_name_by_id(set_user_with_st_types)
return application_with_tasks_id
application_with_tasks_id fixture has function scope as well, set_user_with_st_types has session scope(which I do not wish to change) What can I do?
I tried setting the scope specifically, even though I thought it normal for the fixture to run for each test anew by default
Setting the scope did not work

This simple example shows clearly that the tests are executed for each function and that's all (the output file will contain two lines). If it is not the case for you, please follow hoefling's comment and create a reproducible example (your code is both not complete and contains too many irrelevant things).
import pytest
#pytest.fixture # (scope="function") is the default
def setup():
f = open("/tmp/log", "a")
print("One setup", file=f)
f.close()
def test_one(setup):
assert True
def test_two(setup):
assert True

Load test data from file Pytest based on env

So I m loading test data from a different file based on the environment I'm meant to run the tests:
TestData/DevTestData.py contains:
data = {"accessToken": "Random Access Token"}
Then I have set up in conftest.py file:
To get the CLI parameter:
def pytest_addoption(parser):
parser.addoption('--environment', action='store')
Then to load the data I use LazySettings from simple-settings as a fixture:
#pytest.fixture
def testData(request):
return LazySettings("TestData." + request.config.getoption("--environment") + "TestData")
The test class looks like this:
class Test_User_Current():
userCurrentFacadeInstance = userCurrentGetAPI_Facade.User_Current_API_Facade()
def test_succesfull_request(self, environmentConfigs, testData):
self.userCurrentFacadeInstance.getRequest_user_current_API(environmentConfigs, testData).\
validateSuccessfullStatusCode().\
validateJsonContents()
CLI is:
py.test --environment Dev
My problem is, I have to pass "testData" for every test method rather then passing it to User_Current_API_Facade()'s constructor, and I cant do that for some reason, if I'm passing it to the constructor and not the test method (test_succesfull_request()) it does not work.
Do you guys have any idea on how to do this in a better way?

How can I provide a non-fixture pytest parameter via a custom decorator?

We have unit tests running via Pytest, which use a custom decorator to start up a context-managed mock echo server before each test, and provide its address to the test as an extra parameter. This works on Python 2.
However, if we try to run them on Python 3, then Pytest complains that it can't find a fixture matching the name of the extra parameter, and the tests fail.
Our tests look similar to this:
#with_mock_url('?status=404&content=test&content-type=csv')
def test_file_not_found(self, url):
res_id = self._test_resource(url)['id']
result = update_resource(None, res_id)
assert not result, result
self.assert_archival_error('Server reported status error: 404 Not Found', res_id)
With a decorator function like this:
from functools import wraps
def with_mock_url(url=''):
"""
Start a MockEchoTestServer and call the decorated function with the server's address prepended to ``url``.
"""
def decorator(func):
#wraps(func)
def decorated(*args, **kwargs):
with MockEchoTestServer().serve() as serveraddr:
return func(*(args + ('%s/%s' % (serveraddr, url),)), **kwargs)
return decorated
return decorator
On Python 2 this works; the mock server starts, the test gets a URL similar to "http://localhost:1234/?status=404&content=test&content-type=csv", and then the mock is shut down afterward.
On Python 3, however, we get an error, "fixture 'url' not found".
Is there perhaps a way to tell Python, "This parameter is supplied from elsewhere and doesn't need a fixture"? Or is there, perhaps, an easy way to turn this into a fixture?

You can use url as args parameter
#with_mock_url('?status=404&content=test&content-type=csv')
def test_file_not_found(self, *url):
url[0] # the test url

Looks like Pytest is content to ignore it if I add a default value for the injected parameter, to make it non-mandatory:
#with_mock_url('?status=404&content=test&content-type=csv')
def test_file_not_found(self, url=None):
The decorator can then inject the value as intended.

consider separating the address from the service of the url. Using marks and changing fixture behavior based on the presence of said marks is clear enough. Mock should not really involve any communication, but if you must start some service, then make it separate from
with_mock_url = pytest.mark.mock_url('http://www.darknet.go')
#pytest.fixture
def url(request):
marker = request.get_closest_marker('mock_url')
if marker:
earl = marker.args[0] if args else marker.kwargs['fake']
if earl:
return earl
try:
#
earl = request.param
except AttributeError:
earl = None
return earl
#fixture
def server(request):
marker = request.get_closest_marker('mock_url')
if marker:
# start fake_server
#with_mock_url
def test_resolve(url, server):
server.request(url)

How to check if mock functions has been called?

I'm writing unit tests for a simple function that writes bytes into s3:
import s3fs
def write_bytes_as_csv_to_s3(payload, bucket, key):
fs = s3fs.S3FileSystem()
fname = f"{bucket}/{key}"
print(f"writing {len(payload)} bytes to {fname}")
with fs.open(fname, "wb") as f:
f.write(payload)
return fname
def test_write_bytes_as_csv_to_s3(mocker):
s3fs_mock = mocker.patch('s3fs.S3FileSystem')
open_mock = mocker.MagicMock()
# write_mock = mocker.MagicMock()
# open_mock.write.return_value = write_mock
s3fs_mock.open.invoke.return_value = open_mock
result = write_bytes_as_csv_to_s3('awesome'.encode(), 'random', 'key')
assert result == 'random/key'
s3fs_mock.assert_called_once()
open_mock.assert_called_once()
# write_mock.assert_called_once()
How can I check if method open and write has been called once? Not sure how to set mocker to cover my case.

The unit-test you written above is perfect and mostly covered all the functionality of the methods which you want to test.
In pytest, there is a functionality to get the unittest coverage report which will show the lines covered by unittest.
Kindly install the pytest plugin html-report(if not installed) and execute the following document:-
py.test --cov=<filename to cover: unittest> --cov-report=html <testfile>
After that, you would likely found a html file in the current location o/r in the htmlconv/ directory. And from that, you could easily figure it out about the line covered and also the percentage of the unittest test coverage.

The issue is understanding how each mock is created and what exactly it mocks. For example mocker.patch('s3fs.S3FileSystem') returns a mock of s3fs.S3FileSystem, not the instance returned by calling s3fs.S3FileSystem(). Then to mock with fs.open(fname, "wb") as f you need to mock what the __enter__ dunder method returns. Hopefully the following code makes the relations clear:
def test_write_bytes_as_csv_to_s3(mocker):
# Mock of the open's context manager
open_cm_mock = mocker.MagicMock()
# Mock of the object returned by fs.open()
open_mock = mocker.MagicMock()
open_mock.__enter__.return_value = open_cm_mock
# Mock of the new instance returned by s3fs.S3FileSystem()
fs_mock = mocker.MagicMock()
fs_mock.open.return_value = open_mock
# Patching of s3fs.S3FileSystem
mocker.patch('s3fs.S3FileSystem').return_value = fs_mock
# Running the tested code and making assertions
result = write_bytes_as_csv_to_s3('awesome'.encode(), 'random', 'key')
assert result == 'random/key'
assert open_cm_mock.write.call_count == 1

All my test functions are loading a fixture that is in the conftest.py, even when they don't need it

I have 2 different test files and some fixtures in my conftest.py:
1)"Test_dummy.py" which contains this function:
def test_nothing():
return 1
2)"Test_file.py". which contains this function:
def test_run(excelvalidation_io):
dfInput, expectedOutput=excelvalidation_io
output=run(dfInput)
for key, df in expectedOutput.items():
expected=df.fillna(0)
real=output[key].fillna(0)
assert expected.equals(real)
3)"conftest.py" which contains these fixtures:
def pytest_generate_tests(metafunc):
inputfiles=glob.glob(DATADIR+"**_input.csv", recursive=False)
iofiles=[(ifile, getoutput(ifile)) for ifile in
inputfiles]
metafunc.parametrize("csvio", iofiles)
#pytest.fixture
def excelvalidation_io(csvio):
dfInput, expectedOutput= csvio
return(dfInput, expectedOutput)
#pytest.fixture
def client():
client = app.test_client()
return client
When i run the tests, "Test_dummy.py" also tries to load the "excelvalidation_io" fixture and it generates error:
In test_nothing: function uses no argument 'csvio'
I have tried to place just the fixture inside the "Test_file.py" and the problem is solved, but i read that it's a good practice to locate all the fixtures in the conftest file.

The function pytest_generate_tests is a special function that is always called before executing any test, so in this case you need to check if the metafunc accepts an argument named "csvio" and do nothing otherwise, as in:
def pytest_generate_tests(metafunc):
if "excelvalidation_io" in metafunc.fixturenames:
inputfiles=glob.glob(DATADIR+"**_input.csv", recursive=False)
iofiles=[(ifile, getoutput(ifile)) for ifile in
inputfiles]
metafunc.parametrize("csvio", iofiles)
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