claude-code-safety-net: Instructions file for Claude Code

Agent Guidelines

A Claude Code / OpenCode plugin that blocks destructive git and filesystem commands before execution. Works as a PreToolUse hook intercepting Bash commands.

Commands

Task	Command
Install	bun install
Build	bun run build
All checks	bun run check
Lint	bun run lint
Type check	bun run typecheck
Test all	AGENT=1 bun test
Single test	bun test tests/rules-git.test.ts
Pattern match	bun test --test-name-pattern "pattern"
Dead code	bun run knip
AST rules	bun run sg:scan

bun run check runs: biome check → typecheck → knip → ast-grep scan → bun test

Pre-commit Hooks

Runs on commit (in order): knip → lint-staged (biome check --write)

Commit Conventions

When committing changes to files in commands/, hooks/, or .opencode/, use only fix or feat commit types. These directories contain user-facing skill definitions and hook configurations that represent features or fixes to the plugin's capabilities.

Code Style (TypeScript)

Formatting

• Formatter: Biome
• Line length: configured in biome.json
• Use tabs for indentation (Biome default)

Type Hints

• Required on all functions
• Use | null or | undefined appropriately
• Use lowercase primitive types (string, number, boolean)
• Use readonly arrays where mutation isn't needed

// Good
function analyze(command: string, options?: { strict?: boolean }): string | null { ... }
function analyzeRm(tokens: readonly string[], cwd: string | null): string | null { ... }

// Bad
function analyze(command, strict) { ... }  // Missing types

Imports

• Order: handled by Biome (sorted automatically)
• Use relative imports within same package
• Prefer named exports over default exports

import { parse } from "shell-quote"
import type { Config, HookInput } from "../types"
import { analyzeGit } from "./rules-git"
import { splitShellCommands } from "./shell"