slawekradzyminski reactapp .cursorrules file for TypeScript (stars: 1)

Typescript/JS Conventions:
- Use npm for package management
- Use arrow function syntax (const name = () => {}) instead of function declarations
- Use ES6+ import syntax instead of require()
- Project uses React Router v6
- Omit comments in code

Testing Conventions:
- Use given/when/then pattern in test blocks
- Example test structure:
  it('test description', () => {
    // given
    // setup and mock declarations

    // when
    // action being tested

    // then
    // assertions
  });