Add tests for pybop parameters

tests/unit/test_parameters.py

@@ -0,0 +1,66 @@
+import pybop
+import pytest
+
+
+class TestParameters:
+    """
+    A class to test the parameter classes.
+    """
+
+    @pytest.mark.unit
+    def test_parameter_construction(self):
+        parameter = pybop.Parameter(
+            "Negative electrode active material volume fraction",
+            prior=pybop.Gaussian(0.6, 0.02),
+            bounds=[0.375, 0.7],
+            initial_value=0.6,
+        )
+
+        assert parameter.name == "Negative electrode active material volume fraction"
+        assert parameter.prior.mean == 0.6
+        assert parameter.prior.sigma == 0.02
+        assert parameter.bounds == [0.375, 0.7]
+        assert parameter.initial_value == 0.6
+
+    @pytest.mark.unit
+    def test_parameter_repr(self):
+        parameter = pybop.Parameter(
+            "Negative electrode active material volume fraction",
+            prior=pybop.Gaussian(0.6, 0.02),
+            bounds=[0.375, 0.7],
+            initial_value=0.6,
+        )
+
+        assert (
+            repr(parameter)
+            == "Parameter: Negative electrode active material volume fraction \n Prior: Gaussian, mean: 0.6, sigma: 0.02 \n Bounds: [0.375, 0.7] \n Value: 0.6"
+        )
+
+    @pytest.mark.unit
+    def test_parameter_rvs(self):
+        parameter = pybop.Parameter(
+            "Negative electrode active material volume fraction",
+            prior=pybop.Gaussian(0.6, 0.02),
+            bounds=[0.375, 0.7],
+            initial_value=0.6,
+        )
+
+        samples = parameter.rvs(n_samples=500)
+        assert (samples >= 0.375).all() and (samples <= 0.7).all()
+
+    @pytest.mark.unit
+    def test_parameter_update(self):
+        parameter = pybop.Parameter(
+            "Negative electrode active material volume fraction",
+            prior=pybop.Gaussian(0.6, 0.02),
+            bounds=[0.375, 0.7],
+            initial_value=0.6,
+        )
+
+        # Test value update
+        parameter.update(value=0.534)
+        assert parameter.value == 0.534
+
+        # Test initial value update
+        parameter.update(initial_value=0.654)
+        assert parameter.value == 0.654