From e811b210823b15749afb746b590bb4845ec95d19 Mon Sep 17 00:00:00 2001
From: Kai Chappell <git@kschappell.com>
Date: Mon, 12 May 2025 17:29:00 +0000
Subject: [PATCH] Add power supply simulator tests

Comprehensive test coverage for PowerSupplySim including VOLT, CURR,
OUTP, and MEAS commands. Tests both standalone operation and physics
engine integration.
---
 tests/unit/test_power_supply.py | 352 ++++++++++++++++++++++++++++++++
 1 file changed, 352 insertions(+)
 create mode 100644 tests/unit/test_power_supply.py

diff --git a/tests/unit/test_power_supply.py b/tests/unit/test_power_supply.py
new file mode 100644
index 0000000..d394cfa
--- /dev/null
+++ b/tests/unit/test_power_supply.py
@@ -0,0 +1,352 @@
+"""Unit tests for power supply simulator."""
+
+import pytest
+
+from py_dvt_ate.simulation.physics.engine import PhysicsEngine
+from py_dvt_ate.simulation.virtual.power_supply import PowerSupplySim
+
+
+class TestPowerSupplySimBasic:
+    """Tests for PowerSupplySim without physics engine."""
+
+    @pytest.fixture
+    def psu(self) -> PowerSupplySim:
+        """Create power supply instance without physics engine."""
+        return PowerSupplySim()
+
+    def test_creation(self, psu: PowerSupplySim) -> None:
+        """Test power supply can be created."""
+        assert psu is not None
+        assert psu.model == "PS-SIM-001"
+        assert psu.manufacturer == "PyDVTATE"
+
+    def test_idn_query(self, psu: PowerSupplySim) -> None:
+        """Test *IDN? returns identification string."""
+        response = psu.process("*IDN?")
+
+        assert "PyDVTATE" in response
+        assert "PS-SIM-001" in response
+
+    def test_rst_command(self, psu: PowerSupplySim) -> None:
+        """Test *RST resets to defaults."""
+        # Set non-default values
+        psu.process("VOLT 12.0")
+        psu.process("CURR 2.0")
+        psu.process("OUTP ON")
+
+        # Reset
+        response = psu.process("*RST")
+        assert response == ""
+
+        # Check defaults restored
+        assert psu.process("VOLT?") == "0.000"
+        assert psu.process("CURR?") == "1.000"
+        assert psu.process("OUTP?") == "0"
+
+    def test_opc_query(self, psu: PowerSupplySim) -> None:
+        """Test *OPC? returns 1."""
+        response = psu.process("*OPC?")
+        assert response == "1"
+
+    def test_unknown_command(self, psu: PowerSupplySim) -> None:
+        """Test unknown command returns error."""
+        response = psu.process("INVALID:CMD")
+
+        assert response.startswith("ERROR:")
+        assert "Unknown command" in response
+
+
+class TestPowerSupplyVoltage:
+    """Tests for VOLT command."""
+
+    @pytest.fixture
+    def psu(self) -> PowerSupplySim:
+        """Create power supply instance without physics engine."""
+        return PowerSupplySim()
+
+    def test_volt_query_default(self, psu: PowerSupplySim) -> None:
+        """Test VOLT? returns default value."""
+        response = psu.process("VOLT?")
+
+        assert response == "0.000"
+
+    def test_volt_set(self, psu: PowerSupplySim) -> None:
+        """Test VOLT sets value."""
+        response = psu.process("VOLT 12.5")
+
+        assert response == ""
+        assert psu.process("VOLT?") == "12.500"
+
+    def test_volt_set_decimal(self, psu: PowerSupplySim) -> None:
+        """Test VOLT accepts decimal values."""
+        psu.process("VOLT 3.3")
+
+        assert psu.process("VOLT?") == "3.300"
+
+    def test_volt_set_negative_fails(self, psu: PowerSupplySim) -> None:
+        """Test VOLT rejects negative values."""
+        response = psu.process("VOLT -5.0")
+
+        assert response.startswith("ERROR:")
+        assert "negative" in response
+
+    def test_volt_set_invalid_value(self, psu: PowerSupplySim) -> None:
+        """Test VOLT with invalid value returns error."""
+        response = psu.process("VOLT abc")
+
+        assert response.startswith("ERROR:")
+        assert "Invalid voltage" in response
+
+    def test_volt_set_no_argument(self, psu: PowerSupplySim) -> None:
+        """Test VOLT without argument returns error."""
+        response = psu.process("VOLT")
+
+        assert response.startswith("ERROR:")
+        assert "requires a value" in response
+
+
+class TestPowerSupplyCurrent:
+    """Tests for CURR command."""
+
+    @pytest.fixture
+    def psu(self) -> PowerSupplySim:
+        """Create power supply instance without physics engine."""
+        return PowerSupplySim()
+
+    def test_curr_query_default(self, psu: PowerSupplySim) -> None:
+        """Test CURR? returns default value."""
+        response = psu.process("CURR?")
+
+        assert response == "1.000"
+
+    def test_curr_set(self, psu: PowerSupplySim) -> None:
+        """Test CURR sets value."""
+        response = psu.process("CURR 0.5")
+
+        assert response == ""
+        assert psu.process("CURR?") == "0.500"
+
+    def test_curr_set_negative_fails(self, psu: PowerSupplySim) -> None:
+        """Test CURR rejects negative values."""
+        response = psu.process("CURR -1.0")
+
+        assert response.startswith("ERROR:")
+        assert "negative" in response
+
+    def test_curr_set_invalid_value(self, psu: PowerSupplySim) -> None:
+        """Test CURR with invalid value returns error."""
+        response = psu.process("CURR xyz")
+
+        assert response.startswith("ERROR:")
+        assert "Invalid current" in response
+
+    def test_curr_set_no_argument(self, psu: PowerSupplySim) -> None:
+        """Test CURR without argument returns error."""
+        response = psu.process("CURR")
+
+        assert response.startswith("ERROR:")
+        assert "requires a value" in response
+
+
+class TestPowerSupplyOutput:
+    """Tests for OUTP command."""
+
+    @pytest.fixture
+    def psu(self) -> PowerSupplySim:
+        """Create power supply instance without physics engine."""
+        return PowerSupplySim()
+
+    def test_outp_query_default(self, psu: PowerSupplySim) -> None:
+        """Test OUTP? returns default value (off)."""
+        response = psu.process("OUTP?")
+
+        assert response == "0"
+
+    def test_outp_set_on(self, psu: PowerSupplySim) -> None:
+        """Test OUTP ON enables output."""
+        response = psu.process("OUTP ON")
+
+        assert response == ""
+        assert psu.process("OUTP?") == "1"
+
+    def test_outp_set_1(self, psu: PowerSupplySim) -> None:
+        """Test OUTP 1 enables output."""
+        psu.process("OUTP 1")
+
+        assert psu.process("OUTP?") == "1"
+
+    def test_outp_set_off(self, psu: PowerSupplySim) -> None:
+        """Test OUTP OFF disables output."""
+        psu.process("OUTP ON")
+        psu.process("OUTP OFF")
+
+        assert psu.process("OUTP?") == "0"
+
+    def test_outp_set_0(self, psu: PowerSupplySim) -> None:
+        """Test OUTP 0 disables output."""
+        psu.process("OUTP ON")
+        psu.process("OUTP 0")
+
+        assert psu.process("OUTP?") == "0"
+
+    def test_outp_set_invalid(self, psu: PowerSupplySim) -> None:
+        """Test OUTP with invalid value returns error."""
+        response = psu.process("OUTP MAYBE")
+
+        assert response.startswith("ERROR:")
+        assert "Invalid output state" in response
+
+    def test_outp_set_no_argument(self, psu: PowerSupplySim) -> None:
+        """Test OUTP without argument returns error."""
+        response = psu.process("OUTP")
+
+        assert response.startswith("ERROR:")
+        assert "requires a value" in response
+
+
+class TestPowerSupplyMeasurement:
+    """Tests for MEAS commands."""
+
+    @pytest.fixture
+    def psu(self) -> PowerSupplySim:
+        """Create power supply instance without physics engine."""
+        return PowerSupplySim()
+
+    def test_meas_volt_when_off(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:VOLT? returns 0 when output is off."""
+        psu.process("VOLT 12.0")
+        response = psu.process("MEAS:VOLT?")
+
+        assert response == "0.000"
+
+    def test_meas_volt_when_on_no_engine(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:VOLT? returns setpoint when on without engine."""
+        psu.process("VOLT 12.0")
+        psu.process("OUTP ON")
+        response = psu.process("MEAS:VOLT?")
+
+        assert response == "12.000"
+
+    def test_meas_volt_as_command_fails(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:VOLT (without ?) returns error."""
+        response = psu.process("MEAS:VOLT 5.0")
+
+        assert response.startswith("ERROR:")
+        assert "query only" in response
+
+    def test_meas_curr_when_off(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:CURR? returns 0 when output is off."""
+        response = psu.process("MEAS:CURR?")
+
+        assert response == "0.000"
+
+    def test_meas_curr_when_on_no_engine(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:CURR? returns 0 when on without engine."""
+        psu.process("OUTP ON")
+        response = psu.process("MEAS:CURR?")
+
+        assert response == "0.000"
+
+    def test_meas_curr_as_command_fails(self, psu: PowerSupplySim) -> None:
+        """Test MEAS:CURR (without ?) returns error."""
+        response = psu.process("MEAS:CURR 0.1")
+
+        assert response.startswith("ERROR:")
+        assert "query only" in response
+
+
+class TestPowerSupplyWithPhysicsEngine:
+    """Tests for PowerSupplySim with physics engine integration."""
+
+    @pytest.fixture
+    def engine(self) -> PhysicsEngine:
+        """Create physics engine instance."""
+        return PhysicsEngine(update_rate_hz=100.0)
+
+    @pytest.fixture
+    def psu(self, engine: PhysicsEngine) -> PowerSupplySim:
+        """Create power supply instance with physics engine."""
+        return PowerSupplySim(physics_engine=engine)
+
+    def test_outp_on_enables_engine_output(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test OUTP ON enables physics engine output."""
+        psu.process("VOLT 5.0")
+        psu.process("OUTP ON")
+
+        assert engine.is_output_enabled is True
+
+    def test_outp_off_disables_engine_output(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test OUTP OFF disables physics engine output."""
+        psu.process("OUTP ON")
+        psu.process("OUTP OFF")
+
+        assert engine.is_output_enabled is False
+
+    def test_volt_updates_engine_when_on(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test VOLT updates engine input voltage when output is on."""
+        psu.process("OUTP ON")
+        psu.process("VOLT 5.0")
+
+        electrical = engine.get_electrical_state()
+        assert electrical.input_voltage == pytest.approx(5.0)
+
+    def test_volt_does_not_update_engine_when_off(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test VOLT does not update engine when output is off."""
+        psu.process("VOLT 5.0")
+
+        electrical = engine.get_electrical_state()
+        assert electrical.input_voltage == pytest.approx(0.0)
+
+    def test_meas_volt_returns_engine_voltage(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test MEAS:VOLT? returns physics engine voltage."""
+        psu.process("VOLT 5.0")
+        psu.process("OUTP ON")
+
+        response = psu.process("MEAS:VOLT?")
+        assert response == "5.000"
+
+    def test_meas_curr_returns_engine_current(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test MEAS:CURR? returns total current from engine."""
+        psu.process("VOLT 5.0")
+        psu.process("OUTP ON")
+        engine.set_load_current(0.1)
+
+        # Step engine to allow calculations
+        engine.step()
+
+        response = psu.process("MEAS:CURR?")
+        # Should include load current + quiescent current
+        assert float(response) > 0.0
+
+    def test_reset_disables_engine_output(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test *RST disables physics engine output."""
+        psu.process("VOLT 5.0")
+        psu.process("OUTP ON")
+        psu.process("*RST")
+
+        assert engine.is_output_enabled is False
+
+    def test_reset_sets_engine_voltage_zero(
+        self, psu: PowerSupplySim, engine: PhysicsEngine
+    ) -> None:
+        """Test *RST sets physics engine voltage to zero."""
+        psu.process("VOLT 5.0")
+        psu.process("OUTP ON")
+        psu.process("*RST")
+
+        electrical = engine.get_electrical_state()
+        assert electrical.input_voltage == pytest.approx(0.0)