feat: add JS dependency manager (#666)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests/e2e/utils.py

@@ -0,0 +1,71 @@
+import functools
+import subprocess
+import time
+from pathlib import Path
+
+import requests
+from playwright.async_api import async_playwright
+
+TEST_SERVER_PORT = "8000"
+TEST_SERVER_URL = f"http://127.0.0.1:{TEST_SERVER_PORT}"
+
+
+# NOTE: Ideally we'd use Django's setUpClass and tearDownClass methods
+#       to instantiate the browser instance only once. But didn't have luck with that.
+#       So instead we have to create a browser instance for each test.
+#
+#       Additionally, Django's documentation is lacking on async setUp and tearDown,
+#       so instead we use a decorator to run async code before/after each test.
+def with_playwright(test_func):
+    """Decorator that sets up and tears down Playwright browser instance."""
+
+    @functools.wraps(test_func)
+    async def wrapper(self, *args, **kwargs):
+        # Setup
+        self.playwright = await async_playwright().start()
+        self.browser = await self.playwright.chromium.launch()
+
+        # Test
+        await test_func(self, *args, **kwargs)
+
+        # Teardown
+        await self.browser.close()
+        await self.playwright.stop()
+
+    return wrapper
+
+
+def run_django_dev_server():
+    """Fixture to run Django development server in the background."""
+    # Get the path where testserver is defined, so the command doesn't depend
+    # on user's current working directory.
+    testserver_dir = (Path(__file__).parent / "testserver").absolute()
+
+    # Start the Django dev server in the background
+    print("Starting Django dev server...")
+    proc = subprocess.Popen(
+        ["python", "manage.py", "runserver", f"127.0.0.1:{TEST_SERVER_PORT}", "--noreload"],
+        cwd=testserver_dir,
+    )
+
+    # Wait for the server to start by polling
+    start_time = time.time()
+    while time.time() - start_time < 30:  # timeout after 30 seconds
+        try:
+            response = requests.get(f"http://127.0.0.1:{TEST_SERVER_PORT}")
+            if response.status_code == 200:
+                print("Django dev server is up and running.")
+                break
+        except requests.RequestException:
+            time.sleep(0.1)
+    else:
+        proc.terminate()
+        raise RuntimeError("Django server failed to start within the timeout period")
+
+    yield  # Hand control back to the test session
+
+    # Teardown: Kill the server process after the tests
+    proc.terminate()
+    proc.wait()
+
+    print("Django dev server stopped.")