Prevent stale tracker responses after deletion

app/run.py

@@ -48,6 +48,18 @@
 settings = get_settings()
 
 
+def _is_mutable_user_read(method: str, path: str) -> bool:
+    """Return whether a response reflects tracker or viewer-specific state."""
+    if method != 'GET':
+        return False
+    return (
+        path.startswith('/v1/users/me/')
+        or path.startswith('/v1/public/')
+        or path == '/v1/search'
+        or path.endswith('/search')
+    )
+
+
 # Create FastAPI app
 app = FastAPI(
     title='druthers.io API ' + settings.env,
@@ -128,6 +140,12 @@ async def log_request_latency(request, call_next):
     )
     # Lets the browser's network panel attribute the time without a log dive.
     response.headers['Server-Timing'] = f"app;dur={elapsed_ms:.1f}"
+    # Tracker mutations make public profiles, rankings, and catalog-search
+    # badges stale immediately. These reads are cheap live SQL lookups and
+    # viewer-specific, so do not let a browser, CDN, or framework data cache
+    # retain them under a URL-only key (#297).
+    if _is_mutable_user_read(request.method, request.url.path):
+        response.headers['Cache-Control'] = 'private, no-store'
     return response
 
 

tests/integration/router_delete_cache_test.py

@@ -0,0 +1,112 @@
+# pylint: disable=missing-function-docstring
+"""Deletion consistency for every public shelf and mutable read (#297)."""
+
+import pytest
+from fastapi.testclient import TestClient
+
+DOMAINS = (
+    (
+        'movies',
+        '/v1/movies',
+        {'title': 'Heat', 'imdb': 'tt0113277'},
+        'visibility_movies',
+    ),
+    (
+        'tv-shows',
+        '/v1/tv-shows',
+        {'title': 'Severance', 'tvmaze': 44932},
+        'visibility_tv',
+    ),
+    (
+        'books',
+        '/v1/books',
+        {'title': 'Piranesi', 'isbn': '9781635575637'},
+        'visibility_books',
+    ),
+    (
+        'games',
+        '/v1/games',
+        {'title': 'Hades', 'igdb': 113112},
+        'visibility_games',
+    ),
+)
+
+
+def _auth(token: str) -> dict:
+    return {'Authorization': f'Bearer {token}'}
+
+
+@pytest.mark.parametrize(
+    ('tracker_path', 'catalog_path', 'catalog_payload', 'visibility_field'), DOMAINS
+)
+def test_delete_is_immediately_visible_everywhere(
+    test_client: TestClient,
+    tracker_path: str,
+    catalog_path: str,
+    catalog_payload: dict,
+    visibility_field: str,
+):
+    """A deletion cannot survive in public, rankings, or mutable-read caches."""
+    user_headers = _auth(test_client.first_user.token)
+    item_id = test_client.post(
+        catalog_path,
+        headers=_auth(test_client.admin_user.token),
+        json=catalog_payload,
+    ).json()['id']
+    assert (
+        test_client.post(
+            f'/v1/users/me/{tracker_path}/{item_id}',
+            headers=user_headers,
+            json={'on_rankings': True},
+        ).status_code
+        == 201
+    )
+    test_client.put(
+        '/v1/users/me/visibility',
+        headers=user_headers,
+        json={
+            'handle': 'avery',
+            'visibility_profile': 'public',
+            visibility_field: 'public',
+        },
+    )
+
+    public_before = test_client.get('/v1/public/avery')
+    assert public_before.json()['total_ranked'] == 1
+    assert public_before.headers['cache-control'] == 'private, no-store'
+
+    rankings_before = test_client.get(
+        f'/v1/users/me/{tracker_path}?on_rankings=true', headers=user_headers
+    )
+    assert len(rankings_before.json()) == 1
+    assert rankings_before.headers['cache-control'] == 'private, no-store'
+
+    assert (
+        test_client.delete(
+            f'/v1/users/me/{tracker_path}/{item_id}', headers=user_headers
+        ).status_code
+        == 204
+    )
+
+    public_after = test_client.get('/v1/public/avery')
+    assert public_after.json()['total_ranked'] == 0
+    assert public_after.json()['shelves'][0]['items'] == []
+    assert public_after.headers['cache-control'] == 'private, no-store'
+
+    rankings_after = test_client.get(
+        f'/v1/users/me/{tracker_path}?on_rankings=true', headers=user_headers
+    )
+    assert rankings_after.json() == []
+    assert rankings_after.headers['cache-control'] == 'private, no-store'
+
+
+def test_search_responses_are_not_cacheable(test_client: TestClient, monkeypatch):
+    empty_results = {'movies': [], 'tv_shows': [], 'books': [], 'games': []}
+    monkeypatch.setattr(
+        'app.router.v1.router_search._fan_out', lambda _q: empty_results
+    )
+    response = test_client.get(
+        '/v1/search?q=anything', headers=_auth(test_client.first_user.token)
+    )
+    assert response.status_code == 200
+    assert response.headers['cache-control'] == 'private, no-store'