no-mistakes(review): Guard photo cleanup; add transitions helper and assign auto-advance

tests/test_workflow_hardening.py

@@ -181,6 +181,87 @@ async def test_users_endpoint_lists_technicians(client):
     assert {"id", "full_name", "role"} <= set(users[0].keys())
 
 
+# ── Transitions helper (status dropdown) ─────────────────────────────
+async def test_transitions_helper_returns_valid_targets(client):
+    """GET /api/tickets/{id}/transitions returns the valid next statuses."""
+    from app.services.ticket import VALID_TRANSITIONS
+
+    token = await _login(client)
+    ticket = await _create_ticket(client, token, description="transitions helper")  # status: Logged
+
+    resp = await client.get(f"/api/tickets/{ticket['id']}/transitions")
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert data["current_status"] == "Logged"
+    assert set(data["transitions"]) == set(VALID_TRANSITIONS["Logged"])
+
+
+async def test_transitions_helper_terminal_is_empty(client):
+    """A cancelled ticket exposes no selectable next statuses."""
+    token = await _login(client)
+    ticket = await _create_ticket(client, token, description="terminal transitions")
+    resp = await client.patch(
+        f"/api/tickets/{ticket['id']}",
+        json={"status": "Cancelled"},
+        headers={"Authorization": f"Bearer {token}"},
+    )
+    assert resp.status_code == 200
+
+    data = (await client.get(f"/api/tickets/{ticket['id']}/transitions")).json()
+    assert data["current_status"] == "Cancelled"
+    assert data["transitions"] == []
+
+
+# ── Assign auto-advance ───────────────────────────────────────────────
+async def _first_tech_id(client, token: str) -> int:
+    users = (await client.get("/api/auth/users", headers={"Authorization": f"Bearer {token}"})).json()
+    return next(u["id"] for u in users if u["role"] == "Tech")
+
+
+async def test_assign_auto_advances_to_assigned(client):
+    """Assigning a pre-Assigned ticket advances it to Assigned with a timeline entry."""
+    token = await _login(client)
+    ticket = await _create_ticket(client, token, description="assign advance")  # status: Logged
+    tech_id = await _first_tech_id(client, token)
+
+    resp = await client.patch(
+        f"/api/tickets/{ticket['id']}",
+        json={"assigned_to": tech_id},
+        headers={"Authorization": f"Bearer {token}"},
+    )
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert data["status"] == "Assigned"
+    assert data["assigned_to"] == tech_id
+    assert data["timeline"][-1]["to_status"] == "Assigned"
+
+
+async def test_assign_does_not_regress_past_assigned(client):
+    """Re-assigning a ticket already past Assigned leaves its status untouched."""
+    token = await _login(client)
+    ticket = await _create_ticket(client, token, description="no regression")
+
+    for step in ("Triage", "Assigned", "Accepted"):
+        resp = await client.patch(
+            f"/api/tickets/{ticket['id']}",
+            json={"status": step},
+            headers={"Authorization": f"Bearer {token}"},
+        )
+        assert resp.status_code == 200, resp.text
+
+    users = (await client.get("/api/auth/users", headers={"Authorization": f"Bearer {token}"})).json()
+    techs = [u["id"] for u in users if u["role"] == "Tech"]
+    other_tech = techs[1] if len(techs) > 1 else techs[0]
+
+    resp = await client.patch(
+        f"/api/tickets/{ticket['id']}",
+        json={"assigned_to": other_tech},
+        headers={"Authorization": f"Bearer {token}"},
+    )
+    assert resp.status_code == 200, resp.text
+    assert resp.json()["status"] == "Accepted"
+
+
 # ── Ticket numbering survives deletions ───────────────────────────────
 async def test_ticket_number_uses_max_plus_one(client, seed_tickets):
     """After deleting a middle ticket, numbering must skip over surviving numbers."""