Can anyone help me with my code for timestamp microservice project?

Tell us what’s happening:
Can someone explain why isn’t my code passing the test - “It should return the expected error message for an invalid date” . I think i have tested it for all possible cases. Much appreciated.

Your code so far

  app.get("/api/timestamp/", (req, res) => {
  res.json({ unix:, utc: Date() });

app.get("/api/timestamp/:date_string", (req, res) => {
  let dateString = req.params.date_string;

  //A 4 digit number is a valid ISO-8601 for the beginning of that year
  //5 digits or more must be a unix time, until we reach a year 10,000 problem
  if (/\d{5,}/.test(dateString)) {
    // if(/(-)/.test(dateString)){
    //    res.json({ error: "Invaid Date" }); 
    //    }
    const dateInt = parseInt(dateString);
    //Date regards numbers as unix timestamps, strings are processed differently
    res.json({ unix: dateString, utc: new Date(dateInt).toUTCString() });

  let dateObject = new Date(dateString);
  if (dateObject.toString() === "Invalid Date" ) {
    res.json({ error: "Invaid Date" }); 
  } else {
    res.json({ unix: dateObject.valueOf(), utc: dateObject.toUTCString() });

Challenge: APIs and Microservices Projects - Timestamp Microservice

Link to the challenge: