fix(files): a token made as every session ends goes with them, and a file being shared holds its job

backend/tests/test_api_tokens.py

@@ -10,16 +10,19 @@ holds nothing, and a client trying tokens is slowed down.
 from datetime import datetime, timedelta, timezone
 
 import pytest
+from fastapi import Depends, Request
 from fastapi.testclient import TestClient
 from sqlalchemy import select
 
 from app import apitokens
 from app.apitokens import files_caller
+from app.auth import current_user
 from app.downloads import folders, service
 from app.downloads import gc as gcmod
 from app.downloads import upload as uploadmod
 from app.downloads.status import JobStatus
 from app.config import settings
+from app.db import SessionLocal, get_db
 from app.main import app
 from app.models import (
     ApiToken,
@@ -29,9 +32,11 @@ from app.models import (
     FileFolder,
     MediaAsset,
     Notification,
+    User,
 )
 from app.ratelimit import RateLimiter
 from app.routes import tokens as tokens_routes
+from app.routes.auth import bump_session_epoch
 from app.security import hash_token
 
 
@@ -173,6 +178,39 @@ def test_a_token_is_granted_only_the_users_own_folders_and_writes_only_where_upl
     assert db.execute(select(ApiToken)).all() == []
 
 
+@pytest.mark.parametrize("right", ["read", "write"])
+def test_a_folder_granted_is_held_until_the_token_is_in(db, make_user, right):
+    """A delete of the folder at the same moment waits and takes the new grant with it, rather than
+    failing the grant's foreign key."""
+    import threading
+
+    alice = make_user()
+    fid = _own(db, alice.id, "Mine").id
+    body = tokens_routes.TokenIn(
+        name="x", grants=[tokens_routes.GrantIn(folder_id=fid, rights=[right])]
+    )
+    tokens_routes._wanted_grants(db, alice, body)
+    outcome: list[object] = []
+
+    def delete_it():
+        other = SessionLocal()
+        try:
+            outcome.append(folders.delete_own(other, other.get(FileFolder, fid)))
+            other.commit()
+        except Exception as e:  # noqa: BLE001 — the assertion below names what went wrong
+            outcome.append(e)
+        finally:
+            other.close()
+
+    t = threading.Thread(target=delete_it)
+    t.start()
+    t.join(timeout=1)
+    assert t.is_alive()  # the delete waits for the token on its way in
+    db.commit()
+    t.join(timeout=10)
+    assert not isinstance(outcome[0], Exception), outcome
+
+
 def test_a_user_has_at_most_the_ceiling_of_tokens(db, make_user, as_user, monkeypatch):
     monkeypatch.setattr(tokens_routes, "MAX_TOKENS", 2)
     c = as_user(make_user())
@@ -368,6 +406,60 @@ def test_whatever_ends_every_session_ends_every_token_too(db, make_user, client,
     assert revoked.actor_id == alice.id and "every session" in (revoked.summary or "")
 
 
+def test_a_token_asked_for_as_every_session_ends_is_refused(db, make_user, client, override_dep):
+    """The session was still good when its request came in, and ended before the token was made."""
+    alice = make_user(email="alice@example.com")
+    c = _signed_in(client)
+
+    def ended_meanwhile(request: Request, session=Depends(get_db)):
+        user = current_user(request, session)
+        other = SessionLocal()
+        try:
+            bump_session_epoch(other, other.get(User, alice.id))
+            other.commit()
+        finally:
+            other.close()
+        return user
+
+    override_dep(current_user, ended_meanwhile)
+    r = c.post("/api/tokens", json={"name": "late", "preset": "hub"})
+    assert r.status_code == 401
+    assert db.execute(select(ApiToken.id)).scalars().all() == []
+
+
+def test_a_token_made_as_every_session_ends_goes_with_them(db, make_user):
+    """The other order: the token is on its way in when the sessions end."""
+    import threading
+
+    alice = make_user(email="alice@example.com")
+    db.execute(select(User.id).where(User.id == alice.id).with_for_update())  # as create_token
+    raw = apitokens.mint()
+    db.add(ApiToken(user_id=alice.id, name="t", prefix=raw[:12], token_hash=hash_token(raw)))
+    db.flush()
+    outcome: list[object] = []
+
+    def end_sessions():
+        other = SessionLocal()
+        try:
+            bump_session_epoch(other, other.get(User, alice.id))
+            other.commit()
+            outcome.append("done")
+        except Exception as e:  # noqa: BLE001 — the assertion below names what went wrong
+            outcome.append(e)
+        finally:
+            other.close()
+
+    t = threading.Thread(target=end_sessions)
+    t.start()
+    t.join(timeout=1)
+    assert t.is_alive()  # it waits for the token being made
+    db.commit()
+    t.join(timeout=10)
+    assert outcome == ["done"]
+    db.expire_all()
+    assert db.execute(select(ApiToken.id)).scalars().all() == []
+
+
 # --- a token that does not hold ------------------------------------------------------------------