frontend: date UTC convertite in ora italiana alla presentazione (#42)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/frontend/flask_app/tests/test_local_dt.py

@@ -0,0 +1,31 @@
+"""Filtro local_dt: il backend parla UTC, la presentazione e' in Europe/Rome (#42)."""
+from datetime import datetime, timezone
+
+import pytest
+
+
+@pytest.fixture
+def local_dt(flask_app):
+    return flask_app.jinja_env.filters["local_dt"]
+
+
+def test_summer_time(local_dt):
+    assert local_dt("2026-10-06T08:00:00+00:00") == "06/10/2026 10:00"
+
+
+def test_winter_time(local_dt):
+    assert local_dt("2026-01-15T08:00:00+00:00") == "15/01/2026 09:00"
+
+
+def test_naive_is_utc(local_dt):
+    assert local_dt("2026-10-06T08:00:00") == "06/10/2026 10:00"
+
+
+def test_datetime_object_and_format(local_dt):
+    dt = datetime(2026, 10, 6, 8, 0, tzinfo=timezone.utc)
+    assert local_dt(dt, "%H:%M") == "10:00"
+
+
+@pytest.mark.parametrize("empty", [None, ""])
+def test_empty(local_dt, empty):
+    assert local_dt(empty) == "-"

src/frontend/flask_app/tests/test_measure.py

@@ -407,6 +407,21 @@ class TestTaskComplete:
         assert resp.status_code == 200
         assert b"productionClock(" in resp.data
 
+    def test_measured_at_shown_in_local_time(self, logged_in_client, mock_api_client):
+        """#42: the API sends UTC; the summary shows Europe/Rome."""
+        mock_api_client.get.side_effect = [
+            {"id": 1, "code": "REC-001", "name": "Test Recipe", "version": 1},
+            [{"id": 1, "title": "Task 1", "order_index": 0, "subtasks": [
+                {"id": 1, "marker_number": 1, "description": "d", "nominal": 1.0,
+                 "unit": "mm"}]}],
+            None,
+            {"items": [{"id": 1, "subtask_id": 1, "value": 1.0, "pass_fail": "pass",
+                        "measured_at": "2026-10-06T08:00:00+00:00"}]},
+        ]
+        resp = logged_in_client.get("/measure/complete/1?version_id=5")
+        assert resp.status_code == 200
+        assert "06/10/2026 10:00" in resp.get_data(as_text=True)
+
     def test_measurements_filtered_by_lot_serial_and_operator(
         self, logged_in_client, mock_api_client,
     ):