chore: add claude code support

Author: mdjastrzebski

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is the **React Native Testing Library (RNTL)** - a comprehensive testing solution for React Native applications that provides React Native runtime simulation on top of `react-test-renderer`. The library encourages better testing practices by focusing on testing behavior rather than implementation details.
+
+## Key Development Commands
+
+### Testing
+- `yarn test` - Run all tests
+- `yarn test:ci` - Run tests with CI optimizations (maxWorkers=2)
+- `yarn test:ci:coverage` - Run tests with coverage reporting
+
+### Building
+- `yarn build` - Full build process (clean, build JS, build types, copy flow types)
+- `yarn build:js` - Build JavaScript using Babel
+- `yarn build:ts` - Build TypeScript declarations
+- `yarn clean` - Clean build directory
+
+### Code Quality
+- `yarn typecheck` - Run TypeScript compiler
+- `yarn lint` - Run ESLint with caching
+- `yarn validate` - Run lint + typecheck + test (pre-commit validation)
+
+### Testing Single Files
+To test a specific file: `yarn test path/to/test.test.tsx`
+
+## Architecture Overview
+
+### Core Components
+
+1. **`src/index.ts`** - Main entry point that sets up auto-cleanup and extends Jest matchers
+2. **`src/pure.ts`** - Pure exports without auto-cleanup for advanced use cases
+3. **`src/render.tsx`** - Core rendering functionality using `react-test-renderer`
+4. **`src/screen.ts`** - Global screen object providing access to rendered components
+
+### Key Modules
+
+- **`src/queries/`** - Query functions for finding elements (byText, byRole, byTestId, etc.)
+- **`src/matchers/`** - Jest matchers for assertions (toBeVisible, toHaveTextContent, etc.)
+- **`src/user-event/`** - User interaction simulation (press, type, scroll, etc.)
+- **`src/helpers/`** - Utility functions for component tree traversal and debugging
+- **`src/fire-event.ts`** - Low-level event firing utilities
+
+### Query System
+
+The library provides three query variants for each selector:
+- `get*` - Throws if not found (for assertions)
+- `query*` - Returns null if not found (for conditional logic)
+- `find*` - Returns Promise, waits for element (for async operations)
+
+### User Events vs Fire Events
+
+- **User Events** (`src/user-event/`) - High-level, realistic user interactions
+- **Fire Events** (`src/fire-event.ts`) - Low-level, direct event dispatching
+
+## Configuration
+
+### Jest Setup
+- Main Jest config: `jest.config.js`
+- Setup file: `jest-setup.ts`
+- Uses React Native preset with custom transform ignore patterns
+
+### TypeScript
+- Main config: `tsconfig.json` (development)
+- Release config: `tsconfig.release.json` (for builds)
+- Strict mode enabled with ES2022 target
+
+### ESLint
+- Config: `eslint.config.mjs`
+- Uses Callstack config + TypeScript strict rules
+- Custom rules for import sorting and test files
+
+## Testing Patterns
+
+### Component Testing
+```jsx
+import { render, screen, userEvent } from '@testing-library/react-native';
+
+test('component behavior', async () => {
+  const user = userEvent.setup();
+  render(<MyComponent />);
+  
+  await user.press(screen.getByRole('button'));
+  expect(screen.getByText('Expected text')).toBeOnTheScreen();
+});
+```
+
+### Async Testing
+Use `findBy*` queries or `waitFor` for async operations:
+```jsx
+const element = await screen.findByText('Async content');
+await waitFor(() => expect(mockFn).toHaveBeenCalled());
+```
+
+## Development Workflow
+
+1. **Working with Examples**: Test changes in `examples/` directory
+2. **Commit Messages**: Follow conventional commits (feat:, fix:, docs:, test:, chore:, refactor:, BREAKING:)
+3. **Pre-commit**: Hooks verify linting, type checking, and tests pass
+4. **Pull Requests**: Run `yarn validate` before submitting
+
+## Build Process
+
+The build creates:
+- `build/` - Compiled JavaScript and TypeScript declarations
+- `matchers.js` - Jest matchers for separate import
+- `pure.js` - Pure version without auto-cleanup
+- `dont-cleanup-after-each.js` - Version without auto-cleanup
+
+## Package Structure
+
+- **Main exports**: Full library with auto-cleanup
+- **Pure exports**: Library without auto-cleanup (`/pure`)
+- **Matcher exports**: Jest matchers only (`/matchers`)
+- **No cleanup**: Disable auto-cleanup (`/dont-cleanup-after-each`)
+
+## Testing Environment
+
+- Uses `react-test-renderer` for component rendering
+- Fake timers recommended for user events
+- String validation available for text rendering checks
+- Supports both concurrent and legacy React rendering modes