jest.config.js

module.exports = {
  // The root of your source code, typically /src
  // `<rootDir>` is a token Jest substitutes
  roots: ['<rootDir>/src'],
  moduleDirectories: ['node_modules', 'utils', __dirname],

  // Jest transformations -- this adds support for TypeScript
  // using ts-jest
  transform: {
    '^.+\\.tsx?$': 'ts-jest',
  },

  // Runs special logic, such as cleaning up components
  // when using React Testing Library and adds special
  // extended assertions to Jest
  setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],

  // Test spec file resolution pattern
  // Matches parent folder `__tests__` and filename
  // should contain `test` or `spec`.
  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',

  // Module file extensions for importing
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
  collectCoverage: true,
  collectCoverageFrom: [
    '**/*.{ts,tsx}',
    '!**/*.{d.ts}',
    '!**/node_modules/**',
    '!../build/**',
    '!**/globals.d.ts',
    '!**/styles/**',
    '!**/dist/**',
    '!**/index.ts',
    '!**/styled.ts',
    '!**/utils/test-utils.tsx',
  ],
}