function textNormalizer(text) {
  //
  return text.toLowerCase().trim();
}

// tests

function testTextNormalizer() {
  var text = "   let's GO SURFING NOW everyone is learning how   ";
  var expected = "let's go surfing now everyone is learning how";
  if (textNormalizer(text) === expected) {
    console.log('SUCCESS: `textNormalizer` is working');
  }
  else {
    console.log('FAILURE: `textNormalizer` is not working');
  }
}

testTextNormalizer();