AGENTS.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Development Commands

The project uses pnpm workspaces. Key commands:

pnpm build - Build all packages (runs recursive build command)
pnpm vitest run - Run all tests with Vitest
pnpm vitest run <path> - Run specific test file (e.g., packages/zod/src/v4/classic/tests/string.test.ts)
pnpm vitest run <path> -t "<pattern>" - Run specific test(s) within a file (e.g., -t "MAC")
pnpm vitest run --update - Update all test snapshots
pnpm vitest run <path> --update - Update snapshots for specific test file
pnpm test:watch - Run tests in watch mode
pnpm vitest run --coverage - Run tests with coverage report
pnpm dev - Execute code with tsx under source conditions
pnpm dev <file> - Execute <file> with tsx & proper resolution conditions. Usually use for play.ts.
pnpm dev:play - Quick alias to run play.ts for experimentation
pnpm lint - Run biome linter with auto-fix
pnpm format - Format code with biome
pnpm fix - Run both format and lint

Node.js v24+ required (use nvm if needed); pnpm v10.12.1
ES modules are used throughout ("type": "module")
All tests must be written in TypeScript - never use JavaScript
Use play.ts for quick experimentation; use proper tests for all permanent test cases
Features without tests are incomplete - every new feature or bug fix needs test coverage
Don't skip tests due to type issues - fix the types instead
Test both success and failure cases with edge cases
No log statements (console.log, debugger) in tests or production code
Ask before generating new files
Use util.defineLazy() for computed properties to avoid circular dependencies
Performance is critical - parameter reassignment is allowed for optimization
ALWAYS use the gh CLI to fetch GitHub information (issues, PRs, etc.) instead of relying on web search or assumptions