text: import checkFile from "check-ecmascript-version-compatibility";
  import ensure from "./ensure.es6.js";
  
  describe('compability check', function () {
    it('es6 compliant', (done) => {
      function callback(data) {
        try {
          expect(data).toBe(undefined);
          done();
        } catch (error) {
          done(error);
        }
      }
  
      checkFile('./src/ensure/ensure.es6.js', 2015, callback)
    });
  });
  
  describe('basic check', () => {
    test('should return default value', () => {
      expect(ensure("true", true, false)).toBe(true);
    });
  
    test('should return given', () => {
      expect(ensure("en", "tr", "en", "de")).toBe("en");
    });
  });