fix: refresh current favicon aliases

backend/bot/app/web/webapp/assets.py

@@ -382,11 +382,15 @@ async def webapp_current_favicon_route(request: web.Request) -> web.Response:
     favicon_url = _resolve_webapp_favicon_url(settings, _resolve_webapp_logo_url(settings))
     digest = _webapp_generated_favicon_digest(favicon_url)
     if digest:
-        return _webapp_favicon_file_response(digest, target_filename)
+        response = _webapp_favicon_file_response(digest, target_filename)
+        response.headers["Cache-Control"] = "no-cache"
+        return response
 
     redirect_url = _webapp_redirectable_favicon_url(favicon_url, target_filename)
     if redirect_url:
-        raise web.HTTPFound(location=redirect_url)
+        redirect = web.HTTPFound(location=redirect_url)
+        redirect.headers["Cache-Control"] = "no-cache"
+        raise redirect
 
     raise web.HTTPNotFound(text="webapp_favicon_not_found")
 

tests/test_webapp_assets.py

@@ -10,6 +10,7 @@ from pathlib import Path
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, patch
 
+from aiohttp import web
 from PIL import Image, ImageOps
 
 from bot.app.web import subscription_webapp
@@ -476,6 +477,7 @@ class WebAppAssetTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(response.status, 200)
         self.assertEqual(response.content_type, "image/png")
         self.assertEqual(response.body, b"touch-icon")
+        self.assertEqual(response.headers["Cache-Control"], "no-cache")
 
     async def test_current_favicon_alias_serves_default_icon_when_unconfigured(self):
         settings = SimpleNamespace(
@@ -492,6 +494,23 @@ class WebAppAssetTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(response.status, 200)
         self.assertEqual(response.content_type, "image/png")
         self.assertGreater(len(response.body), 0)
+        self.assertEqual(response.headers["Cache-Control"], "no-cache")
+
+    async def test_current_favicon_alias_redirect_is_not_cached(self):
+        settings = SimpleNamespace(
+            WEBAPP_ENABLED=True,
+            WEBAPP_LOGO_URL="",
+            WEBAPP_FAVICON_USE_CUSTOM=True,
+            WEBAPP_FAVICON_URL="/uploaded-icon.png",
+            WEBAPP_LOGO_FAVICON_URL="",
+        )
+        request = SimpleNamespace(app={"settings": settings}, path="/icon-192.png")
+
+        with self.assertRaises(web.HTTPFound) as exc:
+            await webapp_assets.webapp_current_favicon_route(request)
+
+        self.assertEqual(exc.exception.location, "/uploaded-icon.png")
+        self.assertEqual(exc.exception.headers["Cache-Control"], "no-cache")
 
     async def test_default_logo_route_serves_bundled_logo(self):
         settings = SimpleNamespace(WEBAPP_ENABLED=True)