Adds unit tests for the spectrum solver

tardis/spectrum/base.py

@@ -48,8 +48,8 @@ def spectrum_real_packets_reabsorbed(self):
     def spectrum_virtual_packets(self):
         if np.all(self.montecarlo_virtual_luminosity == 0):
             warnings.warn(
-                "SpectrumSolver.spectrum_virtual_packets"
-                "is zero. Please run the montecarlo simulation with"
+                "SpectrumSolver.spectrum_virtual_packets "
+                "is zero. Please run the montecarlo simulation with "
                 "no_of_virtual_packets > 0",
                 UserWarning,
             )

tardis/spectrum/tests/test_spectrum_solver.py

@@ -0,0 +1,89 @@
+from pathlib import Path
+
+import astropy.units as u
+import numpy as np
+import pandas as pd
+import pytest
+from astropy.tests.helper import assert_quantity_allclose
+
+from tardis.io.configuration.config_reader import Configuration
+from tardis.simulation.base import Simulation
+from tardis.spectrum.base import SpectrumSolver
+from tardis.tests.fixtures.regression_data import RegressionData
+
+
+class TestSpectrumSolver:
+    regression_data: RegressionData = None
+
+    @pytest.fixture(scope="class")
+    def simulation(
+        self,
+        request,
+        atomic_data_fname,
+        generate_reference,
+        example_configuration_dir: Path,
+    ):
+        config = Configuration.from_yaml(
+            str(example_configuration_dir / "tardis_configv1_verysimple.yml")
+        )
+        config["atom_data"] = atomic_data_fname
+
+        simulation = Simulation.from_config(config)
+        simulation.run_final()
+
+        request.cls.regression_data = RegressionData(request)
+        request.cls.regression_data.sync_hdf_store(simulation)
+
+        return simulation
+
+    def get_expected_data(self, key: str):
+        return pd.read_hdf(self.regression_data.fpath, key)
+
+    def test_initialization(self, simulation):
+        transport_state = simulation.transport.transport_state
+        spectrum_frequency = simulation.transport.spectrum_frequency
+
+        solver = SpectrumSolver(transport_state, spectrum_frequency)
+        assert solver.transport_state == transport_state
+        assert np.array_equal(
+            solver.spectrum_frequency.value, spectrum_frequency.value
+        )
+        assert np.array_equal(
+            solver._montecarlo_virtual_luminosity.value,
+            np.zeros_like(spectrum_frequency.value),
+        )
+        assert solver._integrator is None
+        assert solver.integrator_settings is None
+        assert solver._spectrum_integrated is None
+
+    def test_spectrum_real_packets(self, simulation):
+        transport_state = simulation.transport.transport_state
+        spectrum_frequency = simulation.transport.spectrum_frequency
+
+        solver = SpectrumSolver(transport_state, spectrum_frequency)
+        result = solver.spectrum_real_packets.luminosity
+        key = "simulation/spectrum_solver/spectrum_real_packets/luminosity"
+        expected = self.get_expected_data(key)
+
+        luminosity = u.Quantity(expected, "erg /s")
+
+        assert_quantity_allclose(
+            result,
+            luminosity,
+        )
+
+    def test_spectrum_real_packets_reabsorbed(self, simulation):
+        transport_state = simulation.transport.transport_state
+        spectrum_frequency = simulation.transport.spectrum_frequency
+
+        solver = SpectrumSolver(transport_state, spectrum_frequency)
+        result = solver.spectrum_real_packets_reabsorbed.luminosity
+        key = "simulation/spectrum_solver/spectrum_real_packets_reabsorbed/luminosity"
+        expected = self.get_expected_data(key)
+
+        luminosity = u.Quantity(expected, "erg /s")
+
+        assert_quantity_allclose(
+            result,
+            luminosity,
+        )