feat(server.py): enforce absolute file paths for text file operations to prevent errors related to relative paths

docs(server.py): update descriptions to clarify that file paths must be absolute
test(tests/test_server.py): add tests to ensure handlers raise errors for relative file paths and handle absolute paths correctly

Author: tumf

src/mcp_text_editor/server.py

@@ -2,6 +2,7 @@
 
 import json
 import logging
+import os
 import traceback
 from collections.abc import Sequence
 from typing import Any, Dict, List
@@ -23,7 +24,7 @@ class GetTextFileContentsHandler:
     """Handler for getting text file contents."""
 
     name = "get_text_file_contents"
-    description = "Read text file contents from multiple files and line ranges. Returns file contents with hashes for concurrency control and line numbers for reference. The hashes are used to detect conflicts when editing the files."
+    description = "Read text file contents from multiple files and line ranges. Returns file contents with hashes for concurrency control and line numbers for reference. The hashes are used to detect conflicts when editing the files. File paths must be absolute."
 
     def __init__(self):
         self.editor = TextEditor()
@@ -44,7 +45,7 @@ def get_tool_description(self) -> Tool:
                             "properties": {
                                 "file_path": {
                                     "type": "string",
-                                    "description": "Path to the text file",
+                                    "description": "Path to the text file. File path must be absolute.",
                                 },
                                 "ranges": {
                                     "type": "array",
@@ -81,11 +82,15 @@ def get_tool_description(self) -> Tool:
     async def run_tool(self, arguments: Dict[str, Any]) -> Sequence[TextContent]:
         """Execute the tool with given arguments."""
         try:
-            # Check for required argument 'files'
             if "files" not in arguments:
                 raise RuntimeError("Missing required argument: 'files'")
 
-            # Handle request
+            for file_info in arguments["files"]:
+                if not os.path.isabs(file_info["file_path"]):
+                    raise RuntimeError(
+                        f"File path must be absolute: {file_info['file_path']}"
+                    )
+
             encoding = arguments.get("encoding", "utf-8")
             result = await self.editor.read_multiple_ranges(
                 arguments["files"], encoding=encoding
@@ -104,7 +109,7 @@ class EditTextFileContentsHandler:
     """Handler for editing text file contents."""
 
     name = "edit_text_file_contents"
-    description = "A line editor that supports editing text file contents by specifying line ranges and content. It handles multiple patches in a single operation with hash-based conflict detection. IMPORTANT: (1) Before using this tool, you must first get the file's current hash and range hashes and line numbers using get_text_file_contents. (2) To avoid line number shifts affecting your patches, use get_text_file_contents to read the SAME ranges you plan to edit before making changes. different line numbers have different rangehashes.(3) Patches must be specified from bottom to top to handle line number shifts correctly, as edits to lower lines don't affect the line numbers of higher lines. (4) To append content to a file, first get the total number of lines with get_text_file_contents, then specify a patch with line_start = total_lines + 1 and line_end = total_lines. This indicates an append operation and range_hash is not required. Similarly, range_hash is not required for new file creation."
+    description = "A line editor that supports editing text file contents by specifying line ranges and content. It handles multiple patches in a single operation with hash-based conflict detection. File paths must be absolute. IMPORTANT: (1) Before using this tool, you must first get the file's current hash and range hashes and line numbers using get_text_file_contents. (2) To avoid line number shifts affecting your patches, use get_text_file_contents to read the SAME ranges you plan to edit before making changes. different line numbers have different rangehashes.(3) Patches must be specified from bottom to top to handle line number shifts correctly, as edits to lower lines don't affect the line numbers of higher lines. (4) To append content to a file, first get the total number of lines with get_text_file_contents, then specify a patch with line_start = total_lines + 1 and line_end = total_lines. This indicates an append operation and range_hash is not required. Similarly, range_hash is not required for new file creation."
 
     def __init__(self):
         self.editor = TextEditor()
@@ -122,8 +127,14 @@ def get_tool_description(self) -> Tool:
                         "items": {
                             "type": "object",
                             "properties": {
-                                "path": {"type": "string"},
-                                "file_hash": {"type": "string"},
+                                "path": {
+                                    "type": "string",
+                                    "description": "Path to the text file. File path must be absolute.",
+                                },
+                                "file_hash": {
+                                    "type": "string",
+                                    "description": "Hash of the file contents when get_text_file_contents is called.",
+                                },
                                 "patches": {
                                     "type": "array",
                                     "items": {
@@ -175,13 +186,20 @@ async def run_tool(self, arguments: Dict[str, Any]) -> Sequence[TextContent]:
                 return [TextContent(type="text", text=json.dumps(results, indent=2))]
 
             for file_operation in files:
+                # First check if required fields exist
                 if "path" not in file_operation:
                     raise RuntimeError("Missing required field: path")
                 if "file_hash" not in file_operation:
                     raise RuntimeError("Missing required field: file_hash")
                 if "patches" not in file_operation:
                     raise RuntimeError("Missing required field: patches")
 
+                # Then check if path is absolute
+                if not os.path.isabs(file_operation["path"]):
+                    raise RuntimeError(
+                        f"File path must be absolute: {file_operation['path']}"
+                    )
+
                 try:
                     file_path = file_operation["path"]
                     file_hash = file_operation["file_hash"]

tests/test_server.py

@@ -1,6 +1,7 @@
 """Tests for the MCP Text Editor Server."""
 
 import json
+from pathlib import Path
 from typing import List
 
 import pytest
@@ -9,6 +10,8 @@
 from pytest_mock import MockerFixture
 
 from mcp_text_editor.server import (
+    EditTextFileContentsHandler,
+    GetTextFileContentsHandler,
     app,
     call_tool,
     edit_contents_handler,
@@ -44,14 +47,15 @@ async def test_list_tools():
 @pytest.mark.asyncio
 async def test_edit_contents_empty_patches():
     """Test editing file contents with empty patches list."""
-    request = {"files": [{"path": "test.txt", "file_hash": "hash123", "patches": []}]}
+    # Convert relative path to absolute
+    test_path = str(Path("test.txt").absolute())
+    request = {"files": [{"path": test_path, "file_hash": "hash123", "patches": []}]}
 
     response = await edit_contents_handler.run_tool(request)
-    assert isinstance(response, list)
-    assert len(response) == 1
+    assert isinstance(response[0], TextContent)
     content = json.loads(response[0].text)
-    assert content["test.txt"]["result"] == "error"
-    assert content["test.txt"]["reason"] == "Empty patches list"
+    assert content[test_path]["result"] == "error"
+    assert content[test_path]["reason"] == "Empty patches list"
 
 
 @pytest.mark.asyncio
@@ -75,7 +79,9 @@ async def test_get_contents_handler(test_file):
 @pytest.mark.asyncio
 async def test_get_contents_handler_invalid_file(test_file):
     """Test GetTextFileContents handler with invalid file."""
-    args = {"files": [{"file_path": "nonexistent.txt", "ranges": [{"start": 1}]}]}
+    # Convert relative path to absolute
+    nonexistent_path = str(Path("nonexistent.txt").absolute())
+    args = {"files": [{"file_path": nonexistent_path, "ranges": [{"start": 1}]}]}
     with pytest.raises(RuntimeError) as exc_info:
         await get_contents_handler.run_tool(args)
     assert "File not found" in str(exc_info.value)
@@ -159,11 +165,12 @@ async def test_call_tool_error_handling():
         await call_tool("get_text_file_contents", {"invalid": "args"})
     assert "Missing required argument" in str(exc_info.value)
 
-    # Test with invalid file path
+    # Convert relative path to absolute
+    nonexistent_path = str(Path("nonexistent.txt").absolute())
     with pytest.raises(RuntimeError) as exc_info:
         await call_tool(
             "get_text_file_contents",
-            {"files": [{"file_path": "nonexistent.txt", "ranges": [{"start": 1}]}]},
+            {"files": [{"file_path": nonexistent_path, "ranges": [{"start": 1}]}]},
         )
     assert "File not found" in str(exc_info.value)
 
@@ -310,13 +317,13 @@ async def test_edit_contents_handler_malformed_input():
 @pytest.mark.asyncio
 async def test_edit_contents_handler_empty_patches():
     """Test EditTextFileContents handler with empty patches."""
-    edit_args = {
-        "files": [{"path": "test.txt", "file_hash": "any_hash", "patches": []}]
-    }
+    # Convert relative path to absolute
+    test_path = str(Path("test.txt").absolute())
+    edit_args = {"files": [{"path": test_path, "file_hash": "any_hash", "patches": []}]}
     result = await edit_contents_handler.run_tool(edit_args)
     edit_results = json.loads(result[0].text)
-    assert edit_results["test.txt"]["result"] == "error"
-    assert edit_results["test.txt"]["reason"] == "Empty patches list"
+    assert edit_results[test_path]["result"] == "error"
+    assert edit_results[test_path]["reason"] == "Empty patches list"
 
 
 @pytest.mark.asyncio
@@ -462,3 +469,72 @@ async def test_edit_contents_handler_multiple_patches(tmp_path):
         content = f.read()
     assert "Modified Line 2" in content
     assert "Modified Line 4" in content
+
+
+@pytest.mark.asyncio
+async def test_get_contents_relative_path():
+    handler = GetTextFileContentsHandler()
+    with pytest.raises(RuntimeError, match="File path must be absolute:.*"):
+        await handler.run_tool(
+            {
+                "files": [
+                    {"file_path": "relative/path/file.txt", "ranges": [{"start": 1}]}
+                ]
+            }
+        )
+
+
+@pytest.mark.asyncio
+async def test_get_contents_absolute_path():
+    handler = GetTextFileContentsHandler()
+    abs_path = str(Path("/absolute/path/file.txt").absolute())
+
+    # モックを非同期関数として定義
+    async def mock_read_multiple_ranges(*args, **kwargs):
+        return []
+
+    # モックを設定
+    handler.editor.read_multiple_ranges = mock_read_multiple_ranges
+
+    result = await handler.run_tool(
+        {"files": [{"file_path": abs_path, "ranges": [{"start": 1}]}]}
+    )
+    assert isinstance(result[0], TextContent)
+
+
+@pytest.mark.asyncio
+async def test_edit_contents_relative_path():
+    handler = EditTextFileContentsHandler()
+    with pytest.raises(RuntimeError, match="File path must be absolute:.*"):
+        await handler.run_tool(
+            {
+                "files": [
+                    {
+                        "path": "relative/path/file.txt",
+                        "file_hash": "hash123",
+                        "patches": [{"contents": "test"}],
+                    }
+                ]
+            }
+        )
+
+
+@pytest.mark.asyncio
+async def test_edit_contents_absolute_path():
+    handler = EditTextFileContentsHandler()
+    abs_path = str(Path("/absolute/path/file.txt").absolute())
+    # モックを使用して実際のファイル操作を避ける
+    handler.editor.edit_file_contents = lambda *args, **kwargs: {"result": "success"}
+
+    result = await handler.run_tool(
+        {
+            "files": [
+                {
+                    "path": abs_path,
+                    "file_hash": "hash123",
+                    "patches": [{"contents": "test"}],
+                }
+            ]
+        }
+    )
+    assert isinstance(result[0], TextContent)