Fix deepcopy

Author: softwareengineerprogrammer

src/geophires_x_client/geophires_input_parameters.py

@@ -145,12 +145,27 @@ def __hash__(self) -> int:
 
         return hash((param_hash, file_content_hash))
 
+    def __deepcopy__(self, memo):
+        """
+        Return the instance itself for deepcopy, as the object is immutable.
+
+        This implementation prevents a TypeError when `copy.deepcopy` is used
+        on an object containing an instance of this class, as it avoids trying
+        to pickle the internal `mappingproxy` object.
+
+        Args:
+            memo: The memoization dictionary used by `copy.deepcopy` to prevent
+                  infinite recursion in case of circular references.
+        """
+        # Add self to the memoization dictionary to handle circular references correctly.
+        memo[id(self)] = self
+        return self
+
     def as_file_path(self) -> Path:
         """
         Creates a temporary file representation of the parameters on demand.
         The resulting file path is cached on the instance for efficiency.
         """
-
         # Use hasattr to check for the cached attribute on the frozen instance
         if hasattr(self, '_cached_file_path'):
             return self._cached_file_path

tests/geophires_x_client_tests/test_geophires_input_parameters.py

@@ -1,3 +1,4 @@
+import copy
 import tempfile
 import uuid
 from pathlib import Path
@@ -116,3 +117,16 @@ def test_combining_file_and_params_with_no_trailing_newline(self):
 
         # Clean up the temporary file
         base_file_path.unlink()
+
+    def test_deepcopy(self):
+        """Verify that copy.deepcopy works on an instance without raising a TypeError."""
+        p1 = ImmutableGeophiresInputParameters(params={'Reservoir Depth': 3})
+        p2 = None
+
+        try:
+            p2 = copy.deepcopy(p1)
+        except TypeError:
+            self.fail('copy.deepcopy(ImmutableGeophiresInputParameters) raised TypeError unexpectedly!')
+
+        # For an immutable object, deepcopy should ideally return the same instance.
+        self.assertIs(p1, p2)