fix: prevent 'NoneType' error when scanning single Cargo.toml files

Signed-off-by: Om Santosh Suneri <[email protected]>

Author: omsuneri

src/packagedcode/cargo.py

@@ -67,7 +67,13 @@ def assemble(cls, package_data, resource, codebase, package_adder):
                 package_data.extra_data[attribute] = 'workspace'
                 workspace_package_data[attribute] = getattr(package_data, attribute)
 
-        workspace_root_path = resource.parent(codebase).path
+        workspace_root = resource.parent(codebase)
+        if not workspace_root:
+            # If there's no parent (e.g., scanning a single file), use the directory part of the resource path
+            workspace_root_path = os.path.dirname(resource.path)
+        else:
+            workspace_root_path = workspace_root.path
+            
         if workspace_package_data and workspace_members:
 
             # TODO: support glob patterns found in cargo workspaces
@@ -103,12 +109,14 @@ def assemble(cls, package_data, resource, codebase, package_adder):
                     package_adder=package_adder,
                 )
         else:
-            yield from cls.assemble_from_many_datafiles(
-                datafile_name_patterns=('Cargo.toml', 'cargo.toml', 'Cargo.lock', 'cargo.lock'),
-                directory=resource.parent(codebase),
-                codebase=codebase,
-                package_adder=package_adder,
-            )
+            parent_resource = resource.parent(codebase)
+            if parent_resource:
+                yield from cls.assemble_from_many_datafiles(
+                    datafile_name_patterns=('Cargo.toml', 'cargo.toml', 'Cargo.lock', 'cargo.lock'),
+                    directory=parent_resource,
+                    codebase=codebase,
+                    package_adder=package_adder,
+                )
 
     @classmethod
     def update_resource_package_data(cls, workspace, workspace_package_data, resource_package_data, mapping=None):