files not having a JS extension + files with no extension at all

regex.test.js

const r = new RegExp('^(?!.*\.js$).*$');

it('Does not matches .js files', () => {
  expect(r.test('dir/myFile.js')).toBeFalsy();
  expect(r.test('dir.ext/myFile.js')).toBeFalsy();
  expect(r.test('myFile.js')).toBeFalsy();
})

it('Matchs other extensions', () => {
  expect(r.test('dir.something/myFile.other')).toBeTruthy();
  expect(r.test('myFile.other')).toBeTruthy();
  expect(r.test('myFile.jspy')).toBeTruthy();
  expect(r.test('myFile.jsx')).toBeTruthy();
  expect(r.test('myFile.py')).toBeTruthy();

  // It fails for this case
  // expect(r.test('myFile.foojs')).toBeTruthy();
})

it('Matches files with no extension', () => {
  expect(r.test('dir/myFile')).toBeTruthy();
  expect(r.test('myFile')).toBeTruthy();
})