fix: add JSON serialization test for delete handler

To prevent potential JSON serialization errors with EditResult objects,
add a test case that verifies the handler correctly converts
EditResult to a serializable format using to_dict().

- Add test_delete_text_file_contents_handler_success
- Add json import to test file
- Verify response structure and content

Author: tumf

src/mcp_text_editor/handlers/delete_text_file_contents.py

@@ -106,9 +106,16 @@ async def run_tool(self, arguments: Dict[str, Any]) -> Sequence[TextContent]:
             )
 
             # Execute deletion using the service
-            result = self.editor.service.delete_text_file_contents(request)
+            result_dict = self.editor.service.delete_text_file_contents(request)
 
-            return [TextContent(type="text", text=json.dumps(result, indent=2))]
+            # Convert EditResults to dictionaries
+            serializable_result = {}
+            for file_path, edit_result in result_dict.items():
+                serializable_result[file_path] = edit_result.to_dict()
+
+            return [
+                TextContent(type="text", text=json.dumps(serializable_result, indent=2))
+            ]
 
         except Exception as e:
             logger.error(f"Error processing request: {str(e)}")

tests/test_delete_file_contents.py

@@ -1,5 +1,7 @@
 """Tests for delete_text_file_contents functionality."""
 
+import json
+
 import pytest
 
 from mcp_text_editor.models import DeleteTextFileContentsRequest, FileRange
@@ -301,3 +303,43 @@ def delete_text_file_contents(self, request):
         await handler.run_tool(arguments)
 
     assert "Error processing request: Mock error during delete" in str(exc_info.value)
+
+
+@pytest.mark.asyncio
+async def test_delete_text_file_contents_handler_success(tmp_path):
+    """Test successful execution of DeleteTextFileContentsHandler including JSON serialization."""
+    from mcp_text_editor.handlers.delete_text_file_contents import (
+        DeleteTextFileContentsHandler,
+    )
+    from mcp_text_editor.models import EditResult
+    from mcp_text_editor.service import TextEditorService
+    from mcp_text_editor.text_editor import TextEditor
+
+    class MockService(TextEditorService):
+        def delete_text_file_contents(self, request):
+            return {
+                request.file_path: EditResult(result="ok", hash="new_hash", reason=None)
+            }
+
+    editor = TextEditor()
+    editor.service = MockService()
+    handler = DeleteTextFileContentsHandler(editor)
+
+    test_file = tmp_path / "test.txt"
+    test_file.write_text("test content")
+
+    arguments = {
+        "file_path": str(test_file),
+        "file_hash": "some_hash",
+        "ranges": [{"start": 1, "end": 1, "range_hash": "hash1"}],
+    }
+
+    result = await handler.run_tool(arguments)
+    assert len(result) == 1
+    assert result[0].type == "text"
+
+    # Check if response is JSON serializable
+    response = json.loads(result[0].text)
+    assert str(test_file) in response
+    assert response[str(test_file)]["result"] == "ok"
+    assert response[str(test_file)]["hash"] == "new_hash"