Add unit tests for RoutingProblem.get_power

tests/test_routing_problem.py

@@ -0,0 +1,159 @@
+"""
+Unit tests for RoutingProblem.get_power
+
+Tests verify that get_power returns correct structure and physically meaningful
+values given a valid route input, assuming current results are correct.
+"""
+import os
+from datetime import datetime
+from pathlib import Path
+
+import numpy as np
+import pytest
+from astropy import units as u
+
+import tests.basic_test_func as basic_test_func
+from WeatherRoutingTool.algorithms.genetic.problem import RoutingProblem
+from WeatherRoutingTool.config import Config
+from WeatherRoutingTool.ship.ship_config import ShipConfig
+from WeatherRoutingTool.ship.direct_power_boat import DirectPowerBoat
+
+
+# ---------------------------------------------------------------------------
+# Fixtures
+# ---------------------------------------------------------------------------
+
+@pytest.fixture
+def config():
+    """Load the shared test config used across the test suite."""
+    dirname = os.path.dirname(__file__)
+    configpath = os.path.join(dirname, 'config.tests.json')
+    return Config.assign_config(Path(configpath))
+
+
+@pytest.fixture
+def ship_config():
+    """Load the shared ship config used across the test suite."""
+    dirname = os.path.dirname(__file__)
+    configpath = os.path.join(dirname, 'config.tests.json')
+    return ShipConfig.assign_config(Path(configpath))
+
+
+@pytest.fixture
+def boat(ship_config):
+    """Initialise a DirectPowerBoat from the ship config."""
+    return DirectPowerBoat(ship_config)
+
+
+@pytest.fixture
+def constraint_list():
+    """Return a dummy constraint list (no active constraints)."""
+    return basic_test_func.generate_dummy_constraint_list()
+
+
+@pytest.fixture
+def routing_problem(config, boat, constraint_list):
+    """Return a RoutingProblem instance ready for unit testing."""
+    departure_time = datetime(2025, 4, 1, 12, 0)
+    arrival_time   = datetime(2025, 4, 2, 12, 0)
+    objectives     = {"arrival_time": 1.5, "fuel_consumption": 1.5}
+
+    return RoutingProblem(
+        departure_time=departure_time,
+        arrival_time=arrival_time,
+        boat=boat,
+        boat_speed=config.BOAT_SPEED,
+        constraint_list=constraint_list,
+        objectives=objectives,
+    )
+
+
+@pytest.fixture
+def dummy_route():
+    """
+    Minimal valid route array with columns [lat, lon, speed].
+    Route goes from Mediterranean (35N, 15E) to (32N, 28E) — same region
+    used by existing tests in test_genetic.py.
+    """
+    return np.array([
+        [35.199, 15.490, 7.0],
+        [34.804, 16.759, 7.0],
+        [34.447, 18.381, 7.0],
+        [34.142, 18.763, 7.0],
+        [33.942, 21.080, 7.0],
+        [33.542, 23.024, 7.0],
+        [33.408, 24.389, 7.0],
+        [33.166, 26.300, 7.0],
+        [32.937, 27.859, 7.0],
+        [32.737, 28.859, 7.0],
+    ])
+
+
+# ---------------------------------------------------------------------------
+# Tests for RoutingProblem.get_power
+# ---------------------------------------------------------------------------
+
+class TestGetPower:
+    """Unit tests for RoutingProblem.get_power assuming current results are correct."""
+
+    def test_get_power_returns_dict(self, routing_problem, dummy_route):
+        """get_power must return a dictionary."""
+        result = routing_problem.get_power(dummy_route)
+        assert isinstance(result, dict)
+
+    def test_get_power_dict_has_required_keys(self, routing_problem, dummy_route):
+        """Returned dict must contain 'fuel_sum', 'shipparams', and 'time_obj'."""
+        result = routing_problem.get_power(dummy_route)
+        assert "fuel_sum"    in result
+        assert "shipparams"  in result
+        assert "time_obj"    in result
+
+    def test_get_power_fuel_sum_is_positive(self, routing_problem, dummy_route):
+        """Total fuel consumption must be a positive quantity."""
+        result = routing_problem.get_power(dummy_route)
+        fuel = result["fuel_sum"]
+        assert fuel is not None
+        assert fuel.value > 0, f"Expected positive fuel, got {fuel}"
+
+    def test_get_power_fuel_sum_has_mass_unit(self, routing_problem, dummy_route):
+        """Fuel sum must carry a mass unit (kg)."""
+        result = routing_problem.get_power(dummy_route)
+        fuel = result["fuel_sum"]
+        assert fuel.unit.is_equivalent(u.kg), (
+            f"Expected fuel unit equivalent to kg, got {fuel.unit}"
+        )
+
+    def test_get_power_time_obj_is_positive(self, routing_problem, dummy_route):
+        """Arrival-time objective must be a positive scalar."""
+        result = routing_problem.get_power(dummy_route)
+        time_obj = result["time_obj"]
+        assert time_obj is not None
+        assert time_obj > 0, f"Expected positive time_obj, got {time_obj}"
+
+    def test_get_power_shipparams_not_none(self, routing_problem, dummy_route):
+        """ShipParams object must not be None."""
+        result = routing_problem.get_power(dummy_route)
+        assert result["shipparams"] is not None
+
+    def test_get_power_deterministic(self, routing_problem, dummy_route):
+        """Calling get_power twice with the same route must return identical fuel values."""
+        result_one = routing_problem.get_power(dummy_route)
+        result_two = routing_problem.get_power(dummy_route)
+        assert result_one["fuel_sum"].value == pytest.approx(
+            result_two["fuel_sum"].value, rel=1e-6
+        ), "get_power is not deterministic for identical inputs"
+
+    def test_get_power_higher_speed_increases_fuel(self, routing_problem, dummy_route):
+        """A faster route should consume more fuel (sanity / physics check)."""
+        slow_route = dummy_route.copy()
+        fast_route = dummy_route.copy()
+        slow_route[:, 2] = 3.0   # 3 m/s
+        fast_route[:, 2] = 9.0   # 9 m/s
+
+        fuel_slow = routing_problem.get_power(slow_route)["fuel_sum"]
+        fuel_fast = routing_problem.get_power(fast_route)["fuel_sum"]
+
+        assert fuel_fast.value > fuel_slow.value, (
+            f"Expected faster route to burn more fuel: "
+            f"fast={fuel_fast:.2f}, slow={fuel_slow:.2f}"
+        )