ORM: Return None in get_function_source_code instead of excepting

aiida/orm/utils/mixins.py

@@ -8,6 +8,8 @@
 # For further information please visit http://www.aiida.net               #
 ###########################################################################
 """Mixin classes for ORM classes."""
+from __future__ import annotations
+
 import inspect
 from typing import List, Optional
 
@@ -104,12 +106,19 @@ def _set_function_starting_line_number(self, function_starting_line_number):
         """
         self.base.attributes.set(self.FUNCTION_STARTING_LINE_KEY, function_starting_line_number)
 
-    def get_function_source_code(self):
-        """Return the absolute path to the source file in the repository.
+    def get_function_source_code(self) -> str | None:
+        """Return the source code of the function stored in the repository.
+
+        If the source code file does not exist, this will return ``None`` instead. This can happen for example when the
+        function was defined in an interactive shell in which case ``store_source_info`` will have failed to retrieve
+        the source code using ``inspect.getsourcefile``.
 
-        :returns: the absolute path of the source file in the repository, or None if it does not exist
+        :returns: The source code of the function or ``None`` if it could not be determined when storing the node.
         """
-        return self.base.repository.get_object_content(self.FUNCTION_SOURCE_FILE_PATH)
+        try:
+            return self.base.repository.get_object_content(self.FUNCTION_SOURCE_FILE_PATH)
+        except FileNotFoundError:
+            return None
 
 
 class Sealable:

tests/engine/test_process_function.py

@@ -186,6 +186,23 @@ def test_process_function(data):
     assert node.function_name in function_name_from_source
 
 
+@pytest.mark.usefixtures('aiida_profile')
+def test_get_function_source_code():
+    """Test that ``get_function_source_code`` returns ``None`` if no source code was stored.
+
+    This is the case for example for functions defined in an interactive shell, where the retrieval of the source code
+    upon storing the node fails and nothing is stored. The function should not except in this case.
+    """
+    from aiida.orm.utils.mixins import FunctionCalculationMixin
+
+    _, node = function_return_true.run_get_node()
+
+    # Delete the source file by going down to the ``RepositoryBackend`` to circumvent the immutability check.
+    node.base.repository._repository.delete_object(FunctionCalculationMixin.FUNCTION_SOURCE_FILE_PATH)  # pylint: disable=protected-access
+
+    assert node.get_function_source_code() is None
+
+
 @pytest.mark.usefixtures('aiida_profile_clean')
 def test_function_varargs():
     """Variadic arguments are not supported and should raise."""