refactor(test_parameters): removes duplication of ndarray checks via pytest fixture

Author: swastim01

tests/unit/test_parameters/conftest.py

@@ -0,0 +1,16 @@
+import numpy as np
+import pytest
+
+
+@pytest.fixture
+def assert_is_ndarray():
+    """Recursively assert that all items in a structure are numpy arrays."""
+
+    def _assert(obj):
+        if isinstance(obj, list | tuple):
+            for item in obj:
+                _assert(item)
+        else:
+            assert isinstance(obj, np.ndarray)
+
+    return _assert

tests/unit/test_parameters/test_process_parameter_data.py

@@ -4,7 +4,6 @@
 
 from pathlib import Path
 
-import numpy as np
 import pytest
 
 import pybamm
@@ -34,18 +33,13 @@ def test_processed_name(self, parameter_data):
         name, processed = parameter_data
         assert processed[0] == name
 
-    def test_processed_structure(self, parameter_data):
-        name, processed = parameter_data
-        assert isinstance(processed[1], tuple)
-        assert isinstance(processed[1][0][0], np.ndarray)
-        assert isinstance(processed[1][1], np.ndarray)
+    def test_processed_structure(self, parameter_data, assert_is_ndarray):
+        _, processed = parameter_data
 
-        if len(processed[1][0]) > 1:
-            assert isinstance(processed[1][0][1], np.ndarray)
+        assert isinstance(processed[1], tuple)
 
-        elif len(processed[1]) == 3:
-            assert isinstance(processed[1][0][1], np.ndarray)
-            assert isinstance(processed[1][0][2], np.ndarray)
+        # Recursively check that all numpy arrays exist where expected
+        assert_is_ndarray(processed[1])
 
     def test_error(self):
         with pytest.raises(FileNotFoundError, match="Could not find file"):