jest.config.js

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

  // 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: "(/test/.*|(\\.|/)(test|spec))\\.tsx?$",
  // testRegex: "./test/store/reducers/control.test.ts",
  // testRegex: "test/**/*.[jt]s?(x)?$",

  // Module file extensions for importing
  moduleFileExtensions: ["ts", "tsx", "js", "jsx", "json", "node"]
};