Add configuration tests

tests/unit/test_config.py

@@ -0,0 +1,266 @@
+"""Tests for configuration loading and validation."""
+
+from pathlib import Path
+from typing import Any
+
+import pytest
+import yaml
+from pydantic import ValidationError
+
+from py_dvt_ate.app.config import (
+    APIConfig,
+    AppConfig,
+    ChamberConfig,
+    DashboardConfig,
+    DataConfig,
+    DUTConfig,
+    DUTParameters,
+    InstrumentsConfig,
+    LoggingConfig,
+    PhysicsConfig,
+    PyVISAConfig,
+    SimulatorConfig,
+    ThermalConfig,
+    load_config,
+)
+
+
+def test_default_config_values() -> None:
+    """Test that default configuration values are correct."""
+    config = AppConfig()
+
+    assert config.instruments.backend == "simulator"
+    assert config.instruments.simulator.host == "localhost"
+    assert config.instruments.simulator.thermal_chamber_port == 5001
+
+    assert config.physics.update_rate_hz == 100.0
+    assert config.physics.thermal.chamber_time_constant_s == 30.0
+    assert config.physics.thermal.theta_jc == 15.0
+
+    assert config.dut.model == "ldo"
+    assert config.dut.parameters.nominal_output_voltage == 3.3
+    assert config.dut.parameters.tempco_ppm_per_c == 50.0
+
+    assert config.data.database_path == "./data/py_dvt_ate.db"
+    assert config.logging.level == "INFO"
+    assert config.dashboard.enabled is True
+    assert config.api.enabled is False
+
+
+def test_load_config_with_defaults_only() -> None:
+    """Test loading config without a file uses defaults."""
+    config = load_config(None)
+
+    assert config.instruments.backend == "simulator"
+    assert config.physics.update_rate_hz == 100.0
+
+
+def test_load_config_from_file(tmp_path: Path) -> None:
+    """Test loading configuration from YAML file."""
+    config_file = tmp_path / "test_config.yaml"
+    config_data = {
+        "instruments": {"backend": "pyvisa"},
+        "physics": {"update_rate_hz": 50.0},
+        "dut": {"model": "custom_ldo"},
+    }
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    config = load_config(config_file)
+
+    assert config.instruments.backend == "pyvisa"
+    assert config.physics.update_rate_hz == 50.0
+    assert config.dut.model == "custom_ldo"
+    # Defaults still apply
+    assert config.instruments.simulator.host == "localhost"
+
+
+def test_load_config_partial_override(tmp_path: Path) -> None:
+    """Test that partial config overrides work correctly."""
+    config_file = tmp_path / "partial.yaml"
+    config_data = {
+        "physics": {
+            "thermal": {
+                "theta_jc": 20.0,
+                # Other thermal params should use defaults
+            }
+        }
+    }
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    config = load_config(config_file)
+
+    # Overridden value
+    assert config.physics.thermal.theta_jc == 20.0
+    # Default values
+    assert config.physics.thermal.theta_ca == 5.0
+    assert config.physics.thermal.chamber_time_constant_s == 30.0
+
+
+def test_load_config_missing_file() -> None:
+    """Test that loading from missing file raises FileNotFoundError."""
+    with pytest.raises(FileNotFoundError, match="Configuration file not found"):
+        load_config("nonexistent.yaml")
+
+
+def test_load_config_invalid_yaml(tmp_path: Path) -> None:
+    """Test that malformed YAML raises an error."""
+    config_file = tmp_path / "invalid.yaml"
+    config_file.write_text("invalid: yaml: content: [\n")
+
+    with pytest.raises(yaml.YAMLError):
+        load_config(config_file)
+
+
+def test_load_config_validation_error(tmp_path: Path) -> None:
+    """Test that invalid configuration raises ValidationError."""
+    config_file = tmp_path / "invalid_config.yaml"
+    config_data = {
+        "instruments": {"backend": "invalid_backend"},  # Not in Literal["simulator", "pyvisa"]
+    }
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    with pytest.raises(ValidationError):
+        load_config(config_file)
+
+
+def test_env_override_simple(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    """Test environment variable override for simple values."""
+    config_file = tmp_path / "config.yaml"
+    config_data: dict[str, Any] = {}
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__BACKEND", "pyvisa")
+    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "200.0")
+
+    config = load_config(config_file)
+
+    assert config.instruments.backend == "pyvisa"
+    assert config.physics.update_rate_hz == 200.0
+
+
+def test_env_override_nested(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    """Test environment variable override for nested values."""
+    config_file = tmp_path / "config.yaml"
+    config_data: dict[str, Any] = {}
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__SIMULATOR__HOST", "192.168.1.100")
+    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__SIMULATOR__THERMAL_CHAMBER_PORT", "6001")
+    monkeypatch.setenv("PYDVTATE__PHYSICS__THERMAL__THETA_JC", "25.0")
+
+    config = load_config(config_file)
+
+    assert config.instruments.simulator.host == "192.168.1.100"
+    assert config.instruments.simulator.thermal_chamber_port == 6001
+    assert config.physics.thermal.theta_jc == 25.0
+
+
+def test_env_override_types(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    """Test that environment variables are parsed to correct types."""
+    config_file = tmp_path / "config.yaml"
+    config_data: dict[str, Any] = {}
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    monkeypatch.setenv("PYDVTATE__DASHBOARD__ENABLED", "false")  # bool
+    monkeypatch.setenv("PYDVTATE__DASHBOARD__PORT", "9000")  # int
+    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "75.5")  # float
+
+    config = load_config(config_file)
+
+    assert config.dashboard.enabled is False
+    assert config.dashboard.port == 9000
+    assert config.physics.update_rate_hz == 75.5
+
+
+def test_env_override_precedence(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    """Test that environment variables override file values."""
+    config_file = tmp_path / "config.yaml"
+    config_data = {"physics": {"update_rate_hz": 50.0}}
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "150.0")
+
+    config = load_config(config_file)
+
+    # Environment variable should win
+    assert config.physics.update_rate_hz == 150.0
+
+
+def test_env_variables_ignored_without_prefix(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Test that environment variables without prefix are ignored."""
+    config_file = tmp_path / "config.yaml"
+    config_data: dict[str, Any] = {}
+
+    with config_file.open("w") as f:
+        yaml.dump(config_data, f)
+
+    # These should be ignored
+    monkeypatch.setenv("BACKEND", "pyvisa")
+    monkeypatch.setenv("UPDATE_RATE_HZ", "200.0")
+
+    config = load_config(config_file)
+
+    # Should use defaults
+    assert config.instruments.backend == "simulator"
+    assert config.physics.update_rate_hz == 100.0
+
+
+def test_simulator_config_defaults() -> None:
+    """Test SimulatorConfig default values."""
+    config = SimulatorConfig()
+    assert config.host == "localhost"
+    assert config.thermal_chamber_port == 5001
+    assert config.power_supply_port == 5002
+    assert config.multimeter_port == 5003
+
+
+def test_pyvisa_config_defaults() -> None:
+    """Test PyVISAConfig default values."""
+    config = PyVISAConfig()
+    assert config.thermal_chamber is None
+    assert config.power_supply is None
+    assert config.multimeter is None
+
+
+def test_complete_config_structure() -> None:
+    """Test that all config sections can be instantiated."""
+    config = AppConfig(
+        instruments=InstrumentsConfig(
+            backend="pyvisa",
+            simulator=SimulatorConfig(host="192.168.1.1"),
+            pyvisa=PyVISAConfig(thermal_chamber="TCPIP::192.168.1.10::INSTR"),
+        ),
+        physics=PhysicsConfig(
+            update_rate_hz=50.0,
+            thermal=ThermalConfig(theta_jc=20.0),
+            chamber=ChamberConfig(ramp_rate_c_per_min=5.0),
+        ),
+        dut=DUTConfig(
+            model="custom", parameters=DUTParameters(nominal_output_voltage=5.0)
+        ),
+        data=DataConfig(database_path="/tmp/test.db"),
+        logging=LoggingConfig(level="DEBUG"),
+        dashboard=DashboardConfig(enabled=False),
+        api=APIConfig(enabled=True, port=9000),
+    )
+
+    assert config.instruments.backend == "pyvisa"
+    assert config.physics.update_rate_hz == 50.0
+    assert config.dut.parameters.nominal_output_voltage == 5.0
+    assert config.api.port == 9000