How to get PyTest fixtures to autocomplete in PyCharm (type hinting) - pytest

Question

I had a bear of a time figuring this out, and it was really bugging me, so I thought I'd post this here in case anyone hit the same problem...
(and the answer is so dang simple it hurts :-)
The Problem
The core of the issue is that sometimes, not always, when dealing with fixtures in PyTest that return objects, when you use those fixtures in a test in PyCharm, you don't get autocomplete hints. If you have objects with large numbers of methods you want to reference while writing a test, this can add a lot of overhead and inconvenience to the test writing process.
Here's a simple example to illustrate the issue:
Let's say I've got a class "event_manager" that lives in:
location.game.events
Let's further say that in my conftest.py file (PyTest standard thing for the unfamiliar), I've got a fixture that returns an instance of that class:
from location.game.events import event_manager
...
#pytest.fixture(scope="module")
def event_mgr():
"""Creates a new instance of event generate for use in tests"""
return event_manager()
I've had issues sometimes, (but not always - I can't quite figure out why) with classes like this where autocomplete will not work properly in the test code where I use the fixture, e.g.
def test_tc10657(self, evt_mgr):
"""Generates a Regmod and expects filemod to be searchable on server"""
evt_mgr.(This does not offer autocomplete hints when you type ".")
So the answer is actually quite simple, once you review type hinting in PyCharm:
http://www.jetbrains.com/help/pycharm/2016.1/type-hinting-in-pycharm.html
Here's how to fix the above test code so that autocomplete works properly:
from location.game.events import event_manager
...
def test_tc10657(self, evt_mgr: event_manager):
"""Generates a Regmod and expects filemod to be searchable on server"""
evt_mgr.(This DOES offer hints when you type "." Yay!)
Notice how I explicitly type the fixture as an input parameter of type event_manager.

Answer 1

Also if you add a docstring to a function and specify the type of the the parameters, you will get the code completion for those parameters.
For example using pytest and Selenium:
# The remote webdriver seems to be the base class for the other webdrivers
from selenium.webdriver.remote.webdriver import WebDriver
def test_url(url, browser_driver):
"""
This method is used to see if IBM is in the URL title
:param WebDriver browser_driver: The browser's driver
:param str url: the URL to test
"""
browser_driver.get(url)
assert "IBM" in browser_driver.title
Here's my conftest.py file as well
import pytest
from selenium import webdriver
# Method to handle the command line arguments for pytest
def pytest_addoption(parser):
parser.addoption("--driver", action="store", default="chrome", help="Type in browser type")
parser.addoption("--url", action="store", default='https://www.ibm.com', help="url")
#pytest.fixture(scope='module', autouse=True)
def browser_driver(request):
browser = request.config.getoption("--driver").lower()
# yield the driver to the specified browser
if browser == "chrome":
driver = webdriver.Chrome(executable_path='/path/to/chromedriver')
else:
raise Exception("No driver for browser " + browser)
yield driver
driver.quit()
#pytest.fixture(scope="module")
def url(request):
return request.config.getoption("--url")
Tested using Python 2.7 and PyCharm 2017.1. The docstring format is reStructuredText and the "Analyze Python code in docstrings" checkbox is checked in settings.