How to use

statusCode

function

in

Response

app.use((err: Error, req: express.Request, res: express.Response, next: express.NextFunction) => {
  res.status(res.statusCode || 500);
  res.render('error', {
   message: err.message,
   error: err
  });
 });

// Runs after each requests
app.use((req, res, next) => {
 const responseTimeInMs = Date.now() - res.locals.startEpoch

 httpRequestDurationMicroseconds
  .labels(req.method, req.route.path, res.statusCode)
  .observe(responseTimeInMs)

 next()
})

check_csr(request, response, function (code) {
                        if (code === '301-2') {
                          response.status(response.statusCode).end(response.body);
                          request = null;
                          response = null;
                        }
                        else {
                          responder.error_result(request, response, resultStatusCode[code][0], resultStatusCode[code][1], resultStatusCode[code][2], function () {
                            request.connection.release();
                            request = null;
                            response = null;
                          });
                        }
                      });

skip(req, res) {
   return res.statusCode < 400;
  }

// Middleware function to count total requests and the request duration for a given method
app.use((req, res, next) => {
  res.locals.startTime = Date.now()

  next()
  
  Metrics.get("http_requests_total")
    .labels(req.method, req.route.path, res.statusCode)
    .inc()
  
  const responseTimeMS = Date.now() - res.locals.startTime
  Metrics.get("http_duration_histogram_seconds")
    .labels(req.method, req.route.path, res.statusCode)
     .observe(responseTimeMS/1000)
})

// logger
app.use((req, res, next) => {
 const now = new Date().toString().slice(4, 24);
 res.on("finish", () => {
  log.Logger(`${now} ${req.method} ${res.statusCode} ${req.url}`);
 });
 next();
});

// Log every request
router.use(function (req,res,next) {
 next();
 console.log("%s %s => %d", req.method, req.originalUrl, res.statusCode);
});

app.use(function profilerMiddleware(req, res, next) {
 const start = performance.now();

 res.once('finish', () => {
  const routename = req.path.replace('/', '');
  const timing = performance.now() - start;
  
  //Send timer metric to statsd
  metrics.global.timing('api.route.' + routename + '.latency.total', timing);

  //Send counter metric for status code count to statsd    
  metrics.global.increment('api.requests.' + res.statusCode);
 });

 next();
});

app.use(
 morgan(process.env.NODE_ENV !== "production" ? "dev" : "combined", {
  skip: function(req, res) {
   return res.statusCode >= 400;
  },
  stream: process.stdout
 })
);

//downstream middleware: after API endpoint
app.use((req, res, next) => {
 console.log("Downstream middleware -> I'm about to log the request success status")
 console.log(res.statusCode);
 next();
});

app.use(morgan('dev', {
  skip: function (req, res) {
    return res.statusCode >= 400
  }, stream: process.stdout
}));

app.use((req, res, next) => {
 const responseTimeInMs = Date.now() - res.locals.startEpoch;

 httpRequestDurationMicroseconds
  .labels(req.method, req.path, res.statusCode)
  .observe(responseTimeInMs);

 next();
});

app.use(morgan('dev', {
  skip: function (req, res) {
    return res.statusCode < 400
  }, stream: process.stderr
}));

// production error handler
// no stacktraces leaked to user
app.use((err: Error, req: express.Request, res: express.Response, next: express.NextFunction) => {
 res.status(res.statusCode || 500);
 res.render('error', {
  message: err.message,
  error: {}
 });
});

// process.on("SIGINT", function() {
//   console.log("SIGINT received");
//   amIHealthy = false;
//   const timeReceiveSignal = new Date();
//   server.close(function () {
//     console.log(`Server is now closed, it took ${new Date() - timeReceiveSignal}`)
//     process.exit(0);
//   });
// });

//downstream middleware: after API endpoint
app.use((req, res, next) => {
 console.log(
  "Downstream middleware -> I'm about to log the request success status"
 );
 console.log(res.statusCode);
 next();
});