Status 304 Not Modified not being fully used

[GetThatCookie]

When using morgan for example even when client gets

server still shows

[dimdenGD]

I don't get it (also it might show 200 because it uses fetch that handles 3xx status codes automatically)

[GetThatCookie]

I'm using morgan('dev') in our project and on express the statusCode 304 between client and morgan are always correct. But on uExpress I always get 200 in morgan but the client correctly prints 304. In my Screenshot if I additionally set statusCode 304 if req.fresh is true

the result is correct. I couldn't make a reproduction snippet so far.

[dimdenGD]

Can you send request headers of when ure supposed to get 304 returned

[GetThatCookie]

express -> 304

{
  "host": "localhost:3000",
  "connection": "keep-alive",
  "origin": "http://localhost:3000",
  "sec-ch-ua-platform": "\"Linux\"",
  "if-none-match": "W/\"7c96d7-196c3aa722a\"",
  "user-agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36",
  "sec-ch-ua": "\"Not.A/Brand\";v=\"99\", \"Chromium\";v=\"136\"",
  "if-modified-since": "Mon, 12 May 2025 08:44:09 GMT",
  "sec-ch-ua-mobile": "?0",
  "accept": "*/*",
  "sec-fetch-site": "same-origin",
  "sec-fetch-mode": "cors",
  "sec-fetch-dest": "script",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7",
  "cookie": "thingamabob"
}

ultimate-express -> 200

{
  "host": "localhost:3000",
  "connection": "keep-alive",
  "origin": "http://localhost:3000",
  "sec-ch-ua-platform": "\"Linux\"",
  "user-agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36",
  "sec-ch-ua": "\"Not.A/Brand\";v=\"99\", \"Chromium\";v=\"136\"",
  "sec-ch-ua-mobile": "?0",
  "accept": "*/*",
  "sec-fetch-site": "same-origin",
  "sec-fetch-mode": "cors",
  "sec-fetch-dest": "script",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7",
  "cookie": "thingamabob",
  "if-none-match": "W/\"7c8878-196c32b75d2\"",
  "if-modified-since": "Mon, 12 May 2025 06:25:27 GMT"
}

[dimdenGD]

likely something about if-none-match or if-modified-since

[GetThatCookie]

These are only different because I had to rebuild the project with express

[GetThatCookie]

The only difference I see is the time difference because local time was for both 8am

[dimdenGD]

304 is caused by these headers, just so u know what to debug. still need reproduction code

[GetThatCookie]

Maybe this can be used as an extension for the morgan test (two birds with one stone 😄)

// must support morgan middleware

const express = require("express");
const morgan = require("morgan");

const app = express();

app.use(morgan(':method :url :status'));

app.get("/", function (req, res) {
  res.header("Cache-Control", "max-age=3153600");
  res.header("Last-Modified", "Mon, 12 May 2025 08:44:09 GMT");
  res.send("hello, world!");
});

app.listen(13333, async () => {
  console.log("Server is running on port 13333");

  const response1 = await fetch("http://localhost:13333/").then((res) =>
    res.text()
  );
  console.log(response1);

  const response2 = await fetch("http://localhost:13333/", {
    headers: {
      "Cache-Control": "max-age=3153600",
      "If-None-Match": "W/\"d-HwnTDHB9U/PRbFMN1z1wps51lqk\""
    }
  }).then((res) =>
      res.text()
  );
  console.log(response2);

  process.exit(0);
});

[dimdenGD]

if none match should only be sent from client, while last modified should only be sent from server

[GetThatCookie]

Well... copy paste... consider it a test, you passed 😄 -> edited

[dimdenGD]

Isn't morgan just logging middleware? I don't know how is it related to 200/304

[GetThatCookie]

It was just an idea to test it with this, since, as you mentioned, Morgan is a logging middleware, and I noticed that the status isn't set like in Express. Of course, a completely separate test would be appropriate. Nevertheless, I just wanted to show that Express does the following, which isn't the case with uExpress: