Harden live material polling state

tests/test_material_polling_service.py

@@ -1,6 +1,8 @@
 from datetime import UTC, datetime
 from unittest.mock import Mock
 
+import pytest
+
 from production_analytics.calculations.material_consumption import (
     MaterialIntegrationState,
     MaterialSample,
@@ -241,3 +243,85 @@ def test_new_run_of_same_order_keeps_total_but_restarts_integration_at_run_start
         start=run.start,
         end=datetime(2026, 9, 3, 8, 0, 30, tzinfo=UTC),
     )
+
+
+@pytest.fixture
+def polling(tmp_path):
+    from production_analytics.service.material_state_store import JsonMaterialStateStore
+
+    gateway = Mock()
+    gateway.get_open_production_run.return_value = EnlyzeProductionRun(
+        "run", "machine", None, "order", datetime(2026, 9, 3, tzinfo=UTC), None,
+    )
+    gateway.get_material_samples.return_value = []
+    store = JsonMaterialStateStore(tmp_path)
+    service = MaterialPollingService(
+        gateway=gateway, state_store=store, machine_id="machine",
+        rate_variable_id="rate", gate_variable_id="gate", gate_threshold=0.5,
+        max_sample_gap_seconds=20,
+    )
+    return service, gateway, store
+
+
+def test_empty_response_persists_state_without_inferred_consumption(polling) -> None:
+    service, gateway, store = polling
+    now = datetime(2026, 9, 3, 1, tzinfo=UTC)
+    assert service.poll_once(now=now).state == MaterialIntegrationState()
+    saved = MaterialPollingState("run", MaterialIntegrationState(
+        cumulative_consumption_kg=10, integrated_running_seconds=10,
+        last_processed_timestamp=now, last_material_rate_kg_per_hour=3600,
+        last_gate_value=1, integration_active=True,
+    ))
+    store.save("machine", "order", saved)
+    assert service.poll_once(now=now).state == saved.integration_state
+    assert store.load("machine", "order") == saved
+
+
+def test_different_order_does_not_reuse_state(polling) -> None:
+    service, gateway, store = polling
+    store.save("machine", "other-order", MaterialPollingState(
+        "old", MaterialIntegrationState(cumulative_consumption_kg=100),
+    ))
+    result = service.poll_once(now=datetime(2026, 9, 3, 1, tzinfo=UTC))
+    assert result.state == MaterialIntegrationState()
+    assert gateway.get_material_samples.call_args.kwargs["start"] == result.run.start
+    assert store.load("machine", "other-order").integration_state.cumulative_consumption_kg == 100
+
+
+def test_now_before_run_start_does_not_query_or_save(polling) -> None:
+    service, gateway, store = polling
+    assert service.poll_once(now=datetime(2026, 9, 2, tzinfo=UTC)) is None
+    gateway.get_material_samples.assert_not_called()
+    assert store.load("machine", "order") is None
+
+
+def test_naive_now_is_rejected_before_io(polling) -> None:
+    service, gateway, store = polling
+    with pytest.raises(ValueError, match="now must be timezone-aware"):
+        service.poll_once(now=datetime(2026, 9, 3))
+    gateway.get_open_production_run.assert_not_called()
+
+
+def test_new_run_empty_response_resets_baseline_and_retains_totals(polling) -> None:
+    service, gateway, store = polling
+    store.save("machine", "order", MaterialPollingState("previous", MaterialIntegrationState(
+        cumulative_consumption_kg=100, integrated_running_seconds=50,
+        last_processed_timestamp=datetime(2026, 9, 2, 23, 59, 59, tzinfo=UTC),
+        last_material_rate_kg_per_hour=3600, last_gate_value=1, integration_active=True,
+    )))
+    result = service.poll_once(now=datetime(2026, 9, 3, 1, tzinfo=UTC))
+    assert result.state == MaterialIntegrationState(
+        cumulative_consumption_kg=100, integrated_running_seconds=50,
+    )
+    assert store.load("machine", "order") == MaterialPollingState("run", result.state)
+
+
+def test_now_before_saved_timestamp_leaves_state_unchanged(polling) -> None:
+    service, gateway, store = polling
+    saved = MaterialPollingState("run", MaterialIntegrationState(
+        last_processed_timestamp=datetime(2026, 9, 3, 2, tzinfo=UTC),
+    ))
+    store.save("machine", "order", saved)
+    assert service.poll_once(now=datetime(2026, 9, 3, 1, tzinfo=UTC)) is None
+    gateway.get_material_samples.assert_not_called()
+    assert store.load("machine", "order") == saved