Node.js http.validateHeaderName() Method
Last Updated :
06 Apr, 2023
The http.validateHeaderName() (Added in v14.3.0) property is an inbuilt property of the ‘http’ module which performs the low-level validations on the provided name that are done when res.setHeader(name, value) is called. Passing an illegal value as the name will result in a TypeError being thrown, identified by code: "ERR_INVALID_HTTP_TOKEN".
It is not necessary to use this method before passing headers to an HTTP request or response. The HTTP module will automatically validate such headers.
Note: Use the latest version of Node.js to get the required Output.
In order to get a response and a proper result, we need to import ‘http’ module.
const http = require('http');
Syntax:
http.validateHeaderName(name);
Parameters: This property accepts a single parameter as mentioned above and described below:
- name <String>: It accepts the name of the header and it is case-insensitive.
Return Value: It does not return any value, instead validates whether the header is acceptable or not.
The below example illustrates the use of http.validateHeaderName() property in Node.js.
Example 1: Filename: index.js
JavaScript
// Node.js program to demonstrate the
// http.validateHeaderName() Method
// Importing http module
const http = require('http');
const { validateHeaderName } = require('http');
try {
validateHeaderName('');
} catch (err) {
err instanceof TypeError; // true
// ERR_INVALID_HTTP_TOKEN
console.log("Error Occurred", err.code);
// Header name must be a valid
// HTTP token [""]
console.log(err.message);
}
Run the index.js file using the following command:
node index.js
Output:
In Console
>> Error Occurred: 'ERR_INVALID_HTTP_TOKEN'
>> Header name must be a valid HTTP token [""]
Example 2: Filename: index.js
JavaScript
// Node.js program to demonstrate the
// http.validateHeaderName() Method
// Importing http module
const http = require('http');
// Another way to import
const { validateHeaderName } = require('http');
// Setting up PORT
const PORT = process.env.PORT || 3000;
// Creating http Server
const httpServer = http.createServer(
function (request, response) {
// Setting up Headers
response.setHeader('Content-Type', 'text/html');
response.setHeader('Set-Cookie', ['type=ninja',
'language=javascript']);
// Validating headers
try {
validateHeaderName('Content-Type');
console.log("Header 'Content-Type' Validated True...")
http.validateHeaderName('set-cookie');
console.log("Header 'set-cookie' Validated True...")
http.validateHeaderName('alfa-beta');
console.log("Header 'alfa-beta' Validated True...")
validateHeaderName('@@wdjhgw');// not valid
} catch (err) {
err instanceof TypeError;
console.log("Error Occurred", err.code);
// Prints 'Header name must be
// a valid HTTP token [""]'
console.log(err.message);
}
// Getting the set Headers
const headers = response.getHeaders();
// Printing those headers
console.log(headers);
// Prints Output on the browser in response
response.writeHead(200,
{ 'Content-Type': 'text/plain' });
response.end('ok');
});
// Listening to http Server
httpServer.listen(PORT, () => {
console.log("Server is running at port 3000...");
});
Run the index.js file using the following command:
node index.js
Output:
In Console
>> Server is running at port 3000...
Header 'Content-Type' Validated True...
Header 'set-cookie' Validated True...
Header 'alfa-beta' Validated True...
Error Occurred ERR_INVALID_HTTP_TOKEN
Header name must be a valid HTTP token ["@@wdjhgw"]
[Object: null prototype] {
'content-type': 'text/html',
'set-cookie': [ 'type=ninja', 'language=javascript' ]
}
Now run http://localhost:3000/ in the browser.
Output: In Browser
ok
Reference: https://nodejs.org/api/http.html#http_http_validateheadername_name