Add thermal chamber simulator tests

Tests for ThermalChamberSim SCPI command responses:
- Basic IEEE 488.2 commands (*IDN?, *RST, *OPC?)
- TEMP:SETPOINT set/query
- TEMP:ACTUAL? query
- TEMP:STAB? stability query
- Physics engine integration tests

tests/unit/test_thermal_chamber.py

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+"""Unit tests for thermal chamber simulator."""
+
+import pytest
+
+from py_dvt_ate.simulation.physics.engine import PhysicsEngine
+from py_dvt_ate.simulation.virtual.chamber import ThermalChamberSim
+
+
+class TestThermalChamberSimBasic:
+    """Tests for ThermalChamberSim without physics engine."""
+
+    @pytest.fixture
+    def chamber(self) -> ThermalChamberSim:
+        """Create chamber instance without physics engine."""
+        return ThermalChamberSim()
+
+    def test_creation(self, chamber: ThermalChamberSim) -> None:
+        """Test chamber can be created."""
+        assert chamber is not None
+        assert chamber.model == "TC-SIM-001"
+        assert chamber.manufacturer == "PyDVTATE"
+
+    def test_idn_query(self, chamber: ThermalChamberSim) -> None:
+        """Test *IDN? returns identification string."""
+        response = chamber.process("*IDN?")
+
+        assert "PyDVTATE" in response
+        assert "TC-SIM-001" in response
+
+    def test_rst_command(self, chamber: ThermalChamberSim) -> None:
+        """Test *RST resets to defaults."""
+        # Set non-default value
+        chamber.process("TEMP:SETPOINT 85.0")
+        assert chamber.process("TEMP:SETPOINT?") == "85.00"
+
+        # Reset
+        response = chamber.process("*RST")
+        assert response == ""
+        assert chamber.process("TEMP:SETPOINT?") == "25.00"
+
+    def test_opc_query(self, chamber: ThermalChamberSim) -> None:
+        """Test *OPC? returns 1."""
+        response = chamber.process("*OPC?")
+        assert response == "1"
+
+    def test_unknown_command(self, chamber: ThermalChamberSim) -> None:
+        """Test unknown command returns error."""
+        response = chamber.process("INVALID:CMD")
+
+        assert response.startswith("ERROR:")
+        assert "Unknown command" in response
+
+
+class TestThermalChamberSetpoint:
+    """Tests for TEMP:SETPOINT command."""
+
+    @pytest.fixture
+    def chamber(self) -> ThermalChamberSim:
+        """Create chamber instance without physics engine."""
+        return ThermalChamberSim()
+
+    def test_setpoint_query_default(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:SETPOINT? returns default value."""
+        response = chamber.process("TEMP:SETPOINT?")
+
+        assert response == "25.00"
+
+    def test_setpoint_set(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:SETPOINT sets value."""
+        response = chamber.process("TEMP:SETPOINT 85.0")
+
+        assert response == ""
+        assert chamber.process("TEMP:SETPOINT?") == "85.00"
+
+    def test_setpoint_set_negative(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:SETPOINT accepts negative values."""
+        chamber.process("TEMP:SETPOINT -40.0")
+
+        assert chamber.process("TEMP:SETPOINT?") == "-40.00"
+
+    def test_setpoint_set_invalid_value(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:SETPOINT with invalid value returns error."""
+        response = chamber.process("TEMP:SETPOINT abc")
+
+        assert response.startswith("ERROR:")
+        assert "Invalid temperature" in response
+
+    def test_setpoint_set_no_argument(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:SETPOINT without argument returns error."""
+        response = chamber.process("TEMP:SETPOINT")
+
+        assert response.startswith("ERROR:")
+        assert "requires a value" in response
+
+
+class TestThermalChamberActual:
+    """Tests for TEMP:ACTUAL? query."""
+
+    @pytest.fixture
+    def chamber(self) -> ThermalChamberSim:
+        """Create chamber instance without physics engine."""
+        return ThermalChamberSim()
+
+    def test_actual_query_without_engine(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:ACTUAL? returns setpoint when no physics engine."""
+        chamber.process("TEMP:SETPOINT 50.0")
+        response = chamber.process("TEMP:ACTUAL?")
+
+        # Without physics engine, returns setpoint
+        assert response == "50.00"
+
+    def test_actual_as_command_fails(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:ACTUAL (without ?) returns error."""
+        response = chamber.process("TEMP:ACTUAL 25.0")
+
+        assert response.startswith("ERROR:")
+        assert "query only" in response
+
+
+class TestThermalChamberStability:
+    """Tests for TEMP:STAB? query."""
+
+    @pytest.fixture
+    def chamber(self) -> ThermalChamberSim:
+        """Create chamber instance without physics engine."""
+        return ThermalChamberSim()
+
+    def test_stab_query_without_engine(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:STAB? returns 1 when no physics engine."""
+        response = chamber.process("TEMP:STAB?")
+
+        # Without physics engine, assume stable
+        assert response == "1"
+
+    def test_stab_as_command_fails(self, chamber: ThermalChamberSim) -> None:
+        """Test TEMP:STAB (without ?) returns error."""
+        response = chamber.process("TEMP:STAB 1")
+
+        assert response.startswith("ERROR:")
+        assert "query only" in response
+
+
+class TestThermalChamberWithPhysicsEngine:
+    """Tests for ThermalChamberSim with physics engine integration."""
+
+    @pytest.fixture
+    def engine(self) -> PhysicsEngine:
+        """Create physics engine instance."""
+        return PhysicsEngine(update_rate_hz=100.0)
+
+    @pytest.fixture
+    def chamber(self, engine: PhysicsEngine) -> ThermalChamberSim:
+        """Create chamber instance with physics engine."""
+        return ThermalChamberSim(physics_engine=engine)
+
+    def test_setpoint_updates_engine(
+        self, chamber: ThermalChamberSim, engine: PhysicsEngine
+    ) -> None:
+        """Test TEMP:SETPOINT updates physics engine."""
+        chamber.process("TEMP:SETPOINT 85.0")
+
+        # Step the engine and check thermal state
+        thermal = engine.get_thermal_state()
+        # Initial chamber temp is 25, will start moving towards 85
+        assert thermal.chamber_temperature == pytest.approx(25.0, abs=0.1)
+
+        # After many steps, should approach setpoint
+        for _ in range(10000):  # 100 seconds at 100Hz
+            engine.step()
+
+        thermal = engine.get_thermal_state()
+        # Should be closer to setpoint (but not quite there due to time constant)
+        assert thermal.chamber_temperature > 80.0
+
+    def test_actual_query_returns_engine_temperature(
+        self, chamber: ThermalChamberSim, engine: PhysicsEngine
+    ) -> None:
+        """Test TEMP:ACTUAL? returns physics engine temperature."""
+        response = chamber.process("TEMP:ACTUAL?")
+
+        # Should match initial chamber temperature
+        assert response == "25.00"
+
+    def test_stability_when_at_setpoint(
+        self, chamber: ThermalChamberSim, engine: PhysicsEngine
+    ) -> None:
+        """Test TEMP:STAB? returns 1 when at setpoint."""
+        # Default setpoint is 25, engine starts at 25
+        response = chamber.process("TEMP:STAB?")
+
+        assert response == "1"
+
+    def test_stability_when_settling(
+        self, chamber: ThermalChamberSim, engine: PhysicsEngine
+    ) -> None:
+        """Test TEMP:STAB? returns 0 when settling."""
+        # Set new setpoint far from current temperature
+        chamber.process("TEMP:SETPOINT 85.0")
+
+        # Step once to ensure engine updates
+        engine.step()
+
+        # Should not be stable yet
+        response = chamber.process("TEMP:STAB?")
+        assert response == "0"
+
+    def test_reset_updates_engine(
+        self, chamber: ThermalChamberSim, engine: PhysicsEngine
+    ) -> None:
+        """Test *RST resets both chamber and engine setpoint."""
+        chamber.process("TEMP:SETPOINT 85.0")
+        chamber.process("*RST")
+
+        # Check setpoint is back to default
+        assert chamber.process("TEMP:SETPOINT?") == "25.00"