EC
ERR_HTTP_INVALID_STATUS_CODE
Node.jsERRORNotableHTTPHIGH confidence

An invalid HTTP status code was used.

Production Risk

Medium. This is a clear programming error that will cause a request to fail, but it is usually specific to one code path and does not crash the server.

What this means

This error occurs when you attempt to set an invalid HTTP status code on a server response. HTTP status codes must be a 3-digit integer between 100 and 599 (inclusive). Providing a number outside this range, or a non-integer value, will cause Node.js to throw this error to prevent sending a non-compliant HTTP response.

Why it happens
  1. 1Setting `res.statusCode` to a number less than 100 or greater than 599.
  2. 2Accidentally passing a string or other non-numeric value to `res.statusCode`.
  3. 3A bug in code that dynamically calculates a status code, resulting in an invalid value.
How to reproduce

This error is thrown by the HTTP server response object when the `statusCode` property is set to a value that fails the valid range check.

trigger — this will error
trigger — this will error
const http = require('http');
const server = http.createServer((req, res) => {
  try {
    res.statusCode = 999; // Invalid status code
    res.end('This will not be sent');
  } catch (err) {
    // Node.js might handle this internally and close the socket
    console.error(err.code);
  }
});
server.listen(3000);

expected output

ERR_HTTP_INVALID_STATUS_CODE

Fix

Use a Valid HTTP Status Code

WHEN Setting the status code of an HTTP response.

Use a Valid HTTP Status Code
const server = http.createServer((req, res) => {
  // Use a valid, standard status code.
  res.statusCode = 404;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Not Found');
});

Why this works

Ensure that any value set for `res.statusCode` is a number within the valid 100-599 range. Refer to the IANA registry for a list of valid HTTP status codes.

Code examples
Triggerjs
const http = require('http');
const server = http.createServer((req, res) => {
  try {
    res.statusCode = 999; // Invalid status code
    res.end('This will not be sent');
  } catch (err) {  // this triggers ERR_HTTP_INVALID_STATUS_CODE
Handle in try/catchjs
try {
  // operation that may throw ERR_HTTP_INVALID_STATUS_CODE
  riskyOperation()
} catch (err) {
  if (err.code === 'ERR_HTTP_INVALID_STATUS_CODE') {
    console.error('ERR_HTTP_INVALID_STATUS_CODE:', err.message)
  } else {
    throw err
  }
}
Defensive pattern to avoid itjs
// Validate inputs before calling the operation
function safe_err_http_invalid_status_code(...args) {
  // validate args here
  return performOperation(...args)
}
What not to do

✕

✕

Sources
Official documentation ↗

https://github.com/nodejs/node/blob/main/lib/_http_common.js

More information ↗

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