#!/usr/bin/env python3
"""
Claude Code hook for running linter commands after files are modified.
Configure the LINTER_CONFIG dictionary below to map glob patterns to linting commands.
"""
# ruff: noqa: T201
import fnmatch
import json
import subprocess
import sys
from pathlib import Path
# Configuration: Map operating paths to glob patterns and linting commands
# Operating paths define the working directory context for commands
# File paths are matched against {operating_path}/{pattern}
# Use '$@' as a placeholder for the filename (relative to operating path)
LINTER_CONFIG = {
"/": {
# Source TypeScript files - full linting and type checking
"src/**/*.ts": [
["pnpm", "run", "format", "--", "$@"],
["npx", "tsc", "--noEmit", "$@"],
["pnpm", "run", "lint:fix", "--", "$@"],
],
# Test TypeScript files - format and lint only (skip type checking due to different root)
"test/**/*.ts": [
["npx", "prettier", "--write", "$@"],
["npx", "eslint", "--fix", "$@"],
],
# Markdown, JSON files
("*.md", "*.json"): [
["npx", "prettier", "--write", "--log-level=warn", "$@"],
],
},
}
def get_file_path():
"""Get file path from command line argument or Claude hook input."""
# Check for command line argument first
if len(sys.argv) > 1:
return sys.argv[1]
# Fall back to parsing Claude hook input from stdin
try:
hook_data = json.load(sys.stdin)
# Extract file path from tool input (current format)
tool_input = hook_data.get("tool_input", {})
if "file_path" in tool_input:
return tool_input["file_path"]
if "notebook_path" in tool_input:
return tool_input["notebook_path"]
except (json.JSONDecodeError, KeyError):
print("Failed to get file path from command line argument or Claude hook input")
return None
def match_one(file_path, pattern, operating_path):
if isinstance(pattern, tuple):
return any(match_one(file_path, p, operating_path) for p in pattern)
# Build full pattern with operating path
if operating_path == "/":
full_pattern = pattern
else:
full_pattern = f"{operating_path}/{pattern}"
return fnmatch.fnmatch(file_path, full_pattern)
def match_patterns(file_path):
"""Find all glob patterns that match the given file path."""
matching_commands = []
for operating_path, patterns in LINTER_CONFIG.items():
for pattern, commands in patterns.items():
if match_one(file_path, pattern, operating_path):
# Return commands with operating path info
matching_commands.extend((operating_path, command) for command in commands)
return matching_commands
def run_command(operating_path, command, file_path):
"""Execute a linting command with file path substitution."""
# Strip operating path prefix from file path
if operating_path != "/" and file_path.startswith(f"{operating_path}/"):
relative_file_path = file_path[len(operating_path) + 1 :]
else:
relative_file_path = file_path
# Replace '$@' with the relative file path
processed_command = []
for arg in command:
if arg == "$@":
processed_command.append(relative_file_path)
else:
processed_command.append(arg)
# Set working directory
if operating_path == "/":
cwd = Path.cwd()
else:
cwd = Path.cwd() / operating_path
try:
result = subprocess.run(processed_command, capture_output=True, text=True, cwd=cwd)
except FileNotFoundError:
return 1, "", f"Command not found: {processed_command[0]}"
else:
return result.returncode, result.stdout, result.stderr
def main():
"""Main hook execution logic."""
file_path = get_file_path()
if not file_path:
# No file to lint, exit successfully
sys.exit(0)
# Convert to relative path for pattern matching
try:
relative_path = str(Path(file_path).relative_to(Path.cwd()))
except ValueError:
# File is outside working directory, use absolute path
relative_path = file_path
matching_commands = match_patterns(relative_path)
if not matching_commands:
# No linting rules for this file
sys.exit(0)
has_errors = False
for operating_path, command in matching_commands:
returncode, stdout, stderr = run_command(operating_path, command, file_path)
if returncode != 0:
has_errors = True
print(f"Linting failed for {relative_path}:", file=sys.stderr)
print(f"Command: {' '.join(command)} (in {operating_path})", file=sys.stderr)
if stdout:
print(f"STDOUT:\n{stdout}", file=sys.stderr)
if stderr:
print(f"STDERR:\n{stderr}", file=sys.stderr)
print("-" * 50, file=sys.stderr)
# Exit with code 2 to block the action if any linter failed
if has_errors:
sys.exit(2)
else:
sys.exit(0)
if __name__ == "__main__":
main()