window.common = (function({ common = { init: [] }}) {

  var BDDregex = new RegExp(
    '(expect(\\s+)?\\(.*\\;)|' +
    '(assert(\\s+)?\\(.*\\;)|' +
    '(assert\\.\\w.*\\;)|' +
    '(.*\\.should\\..*\\;)/'
  );

  common.addTestsToString = function({ code, tests = [], ...rest }) {
    const userTests = [];

    code = tests.reduce((code, test) => code + test + '\n', code + '\n');

    var counter = 0;
    var match = BDDregex.exec(code);

    while (match) {
      var replacement = '//' + counter + common.salt;
      code = code.substring(0, match.index) +
        replacement +
        code.substring(match.index + match[0].length);

      userTests.push({
        err: null,
        text: match[0],
        line: counter
      });

      counter++;
      match = BDDregex.exec(code);
    }

    return { ...rest, code, userTests };
  };

  return common;
}(window));