frontend_test_mixin.py

"""
Test mixin used for frontend testing. This makes use of Playwright to test the frontend.

Based in https://github.com/mxschmitt/python-django-playwright/blob/master/test_login.py

StaticLiveServerTestCase is described here:
https://docs.djangoproject.com/en/4.2/ref/contrib/staticfiles/#django.contrib.staticfiles.testing.StaticLiveServerTestCase
"""

import os
from django.contrib.staticfiles.testing import StaticLiveServerTestCase
from playwright.sync_api import sync_playwright
from django.urls import reverse


class FrontendTestMixin(StaticLiveServerTestCase):  # <<< Run a server
    def setUp(self):
        super().setUp()
        self.page = self.browser.new_page()  # <<< setting up:
        #                                    #       make a new browser page
        #                                    #       == a tab/popup in a browser
        # self.context = self.browser.new_context()
        # self.context.tracing.start(screenshots=True, snapshots=True, sources=True)

    def tearDown(self) -> None:
        super().tearDown()
        self.page.close()  # <<< teardown: close the page
        #                  # We could also use fixtures
        # breakpoint()
        # self.context.tracing.stop(path="trace.zip")

    @classmethod
    def setUpClass(cls):
        os.environ["DJANGO_ALLOW_ASYNC_UNSAFE"] = (
            "true"  # <<< need to run sync code from an async context
            #       #     models are sync
        )
        super().setUpClass()
        cls.playwright = sync_playwright().start()
        cls.browser = cls.playwright.chromium.launch(headless=False)

    @classmethod
    def tearDownClass(cls):
        super().tearDownClass()
        cls.browser.close()
        cls.playwright.stop()

    def reverse_url(
        self, viewname, urlconf=None, args=None, kwargs=None, current_app=None
    ):
        """A wrapper around Django's reverse function that returns a full URL"""
        end = reverse(viewname, urlconf, args, kwargs, current_app)
        return f"{self.live_server_url}{end}"

    # def do_login(self, user):
    #     """
    #     logs the user in. Assumes the email address ands password are the same.
    #     self.page will be on the page after login
    #     """
    #     self.page.goto(f"{self.live_server_url}/login/")
    #     self.page.fill("[name=username]", user.email)
    #     self.page.fill("[name=password]", user.email)
    #     self.page.click("text=Log in")