Microdot UI Testing with Selenium

[maxi07]

Has anybody experience with testing the webinterface with pytest and selenium?
This is my approach, however my website is not loading and selenium fails, as it can't find the site. Or does anybody use a different (working) framework?

from selenium import webdriver
from selenium.webdriver.firefox.service import Service as FirefoxService
from webdriver_manager.firefox import GeckoDriverManager
from tests.microdot_asyncio_test_client import TestClient
import pytest


driver = webdriver.Firefox(service=FirefoxService(GeckoDriverManager().install()))
# https://pypi.org/project/webdriver-manager/


@pytest.fixture
def client(stub):
    stub.apply({
        'rp2': '[mock]',
        'neopixel': '[mock]',
        'machine': '[mock]',
        'network': '[mock]'
    })
    import settings
    client = TestClient(app=settings.app)
    return client


@pytest.mark.asyncio
async def test_mainpage(client):
    await client.get("/")
    driver.get("http://127.0.0.1")

fails with

selenium.common.exceptions.WebDriverException: Message: Reached error page: about:neterror?e=connectionFailure&u=http%3A//127.0.0.1/&c=UTF-8&d=Firefox%20kann%20keine%20Verbindung%20zu%20dem%20Server%20unter%20127.0.0.1%20aufbauen.

[miguelgrinberg]

I think this is a misunderstanding on your part. Selenium cannot work through the test client. You have to run the real app for it to be able to connect. Try starting the app manually to begin. For the final solution you will need to start the app on a separate thread or process, and stop it when the tests end.

[miguelgrinberg]

Does your test work well if you manually start the server on another terminal? Because you don't seem sure that the web server isn't running, right? Something isn't working there, but if you get the message that the server started my guess is that the issue is on the selenium side.

[maxi07]

No it doesnt seem like the server is running properly. I have tried setting up a minimal example of getting to run a very simple Microdot webserver in Python. It spins up the server and prints Starting async server on 0.0.0.0:5000... but its not accessible.

from modules.Microdot.microdot_asyncio import Microdot
import asyncio

app = Microdot()

async def runserver():
    await app.start_server(debug=True)
    while True:
        await asyncio.sleep(0.1)

@app.get("/")
async def test(request):
    return "Hello"

asyncio.run(runserver())

[miguelgrinberg]

I suggest you start by trying the examples in this repository. If the above code does not work for you, I think there is something there that isn't right.

[maxi07]

When running your example code with normal python, I get the same result. The server spins up and prints the message, but it terminates instantly. But the documentation of app.run() normally states, that the server enters an endless listening loop, which doesn't seem to happen for me.

microdot/examples/hello/hello_async.py

Line 33 in 7a329d9

app.run(debug=True)

[miguelgrinberg]

@maxi07 I can't really diagnose this for you with the little information you provided, but the app.run() function is not supposed to return immediately. If you have made any changes to the microdot source files I suggest you install with pip (which would work fine for CPython), to make sure you are using unmodified code.

[maxi07]

I figured it out and published my sample repo. If anyone stumbles across end to end testing with this, feel free to head over to my sample repository on running click tests using the latest Microdot version.

@miguelgrinberg feel free to mention this in your documentation 😊