feat: allow running from non-root directories

Make 'codemcp run' work even when not in the root dir of the project, by traversing up to project root to find codemcp.toml. Use preexisting functionality to do this.

```git-revs
fb6f20a  (Base revision)
cfd70e1  Snapshot before codemcp change
477cfe9  Snapshot before codemcp change
e9001c6  Snapshot before auto-ghstack
0b8709d  Snapshot before codemcp change
caa5731  Snapshot before auto-ghstack
a532f7b  Snapshot before auto-format
f7d4d34  Auto-commit format changes
HEAD     Auto-commit lint changes
```

codemcp-id: 281-feat-allow-running-from-non-root-directories
ghstack-source-id: 443ba47
Pull-Request-resolved: #275

Author: ezyang

codemcp/common.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 import os
-from typing import List, Union
+from typing import List, Optional, Union
 
 # Constants
 MAX_LINES_TO_READ = 1000
@@ -19,6 +19,7 @@
     "normalize_file_path",
     "get_edit_snippet",
     "truncate_output_content",
+    "find_codemcp_root",
 ]
 
 
@@ -157,3 +158,35 @@ def truncate_output_content(
             truncated_content += f"\n... (output truncated, showing {MAX_LINES_TO_READ} of {total_lines} lines)"
 
     return truncated_content
+
+
+def find_codemcp_root(start_path: str) -> Optional[str]:
+    """Find the root directory containing codemcp.toml, starting from the given path.
+
+    This function traverses up the directory tree from the given path until it finds
+    a directory containing a codemcp.toml file, which indicates the project root.
+
+    Args:
+        start_path: The path to start searching from (can be a file or directory)
+
+    Returns:
+        The absolute path to the directory containing codemcp.toml, or None if not found
+    """
+    path = os.path.abspath(start_path)
+
+    # If the path is a file, start from its parent directory
+    if os.path.isfile(path):
+        path = os.path.dirname(path)
+
+    while path:
+        config_path = os.path.join(path, "codemcp.toml")
+        if os.path.isfile(config_path):
+            return path
+
+        parent = os.path.dirname(path)
+        if parent == path:  # Reached filesystem root
+            return None
+
+        path = parent
+
+    return None

codemcp/main.py

@@ -845,7 +845,7 @@ def run(command: str, args: tuple, path: str) -> None:
 
     import tomli
 
-    from .common import normalize_file_path
+    from .common import find_codemcp_root, normalize_file_path
 
     # Handle the async nature of the function in a sync context
     asyncio.get_event_loop()
@@ -863,12 +863,18 @@ def run(command: str, args: tuple, path: str) -> None:
         click.echo(f"Error: Path {path} is not a directory", err=True)
         return
 
-    # Check for codemcp.toml file
-    config_path = os.path.join(full_path, "codemcp.toml")
-    if not os.path.exists(config_path):
-        click.echo(f"Error: Config file not found: {config_path}", err=True)
+    # Find project root by traversing up to find codemcp.toml
+    project_root = find_codemcp_root(full_path)
+    if project_root is None:
+        click.echo(
+            f"Error: No codemcp.toml file found in {path} or any parent directory",
+            err=True,
+        )
         return
 
+    # Use the project root for config and operations
+    config_path = os.path.join(project_root, "codemcp.toml")
+
     # Load command from config
     try:
         with open(config_path, "rb") as f:
@@ -898,10 +904,10 @@ def run(command: str, args: tuple, path: str) -> None:
         if args:
             cmd_list = list(cmd_list) + list(args)
 
-        # Run the command with inherited stdin/stdout/stderr
+        # Run the command with inherited stdin/stdout/stderr from the project root
         process = subprocess.run(
             cmd_list,
-            cwd=full_path,
+            cwd=project_root,  # Use project root as working directory
             stdin=None,  # inherit
             stdout=None,  # inherit
             stderr=None,  # inherit

e2e/test_run_from_subdir.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+
+import os
+import subprocess
+import sys
+import tempfile
+
+import pytest
+
+from codemcp.main import init_codemcp_project
+
+
+@pytest.fixture
+def project_dir():
+    """Create a temporary project directory with a simple codemcp.toml configuration."""
+    with tempfile.TemporaryDirectory() as temp_dir:
+        # Initialize the project
+        init_codemcp_project(temp_dir)
+
+        # Create a codemcp.toml file with test commands
+        config_path = os.path.join(temp_dir, "codemcp.toml")
+        with open(config_path, "w") as f:
+            f.write("""
+[commands]
+echo = ["echo", "Hello World"]
+pwd = ["pwd"]
+            """)
+
+        # Create a subdirectory
+        subdir = os.path.join(temp_dir, "subdir")
+        os.makedirs(subdir, exist_ok=True)
+
+        yield temp_dir
+
+
+def test_run_command_from_subdir(project_dir):
+    """Test running a command from a subdirectory of the project."""
+    subdir = os.path.join(project_dir, "subdir")
+
+    # Run pwd command from subdirectory to verify cwd
+    result = subprocess.run(
+        [sys.executable, "-m", "codemcp", "run", "pwd", "--path", subdir],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+
+    # The pwd output should show the project root, not the subdirectory
+    # Normalize paths for comparison (strip trailing slashes, etc.)
+    normalized_output = os.path.normpath(result.stdout.strip())
+    normalized_project_dir = os.path.normpath(project_dir)
+    assert normalized_output == normalized_project_dir
+
+
+def test_run_command_from_project_root(project_dir):
+    """Test running a command from the project root."""
+    result = subprocess.run(
+        [sys.executable, "-m", "codemcp", "run", "echo", "--path", project_dir],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+
+    assert "Hello World" in result.stdout