cookie

Basic HTTP cookie parser and serializer for HTTP servers.

Installation

$ npm install cookie

API

var cookie = require('cookie');

Parse an HTTP Cookie header string and returning an object of all cookie name-value pairs. The str argument is the string representing a Cookie header value and options is an optional object containing additional parsing options.

var cookies = cookie.parse('foo=bar; equation=E%3Dmc%5E2');
// { foo: 'bar', equation: 'E=mc^2' }

Options

cookie.parse accepts these properties in the options object.

decode

Specifies a function that will be used to decode a cookie's value. Since the value of a cookie has a limited character set (and must be a simple string), this function can be used to decode a previously-encoded cookie value into a JavaScript string or other object.

The default function is the global decodeURIComponent, which will decode any URL-encoded sequences into their byte representations.

note if an error is thrown from this function, the original, non-decoded cookie value will be returned as the cookie's value.

Serialize a cookie name-value pair into a Set-Cookie header string. The name argument is the name for the cookie, the value argument is the value to set the cookie to, and the options argument is an optional object containing additional serialization options.

var setCookie = cookie.serialize('foo', 'bar');
// foo=bar

Options

cookie.serialize accepts these properties in the options object.

domain

encode

Specifies a function that will be used to encode a cookie's value. Since value of a cookie has a limited character set (and must be a simple string), this function can be used to encode a value into a string suited for a cookie's value.

The default function is the global encodeURIComponent, which will encode a JavaScript string into UTF-8 byte sequences and then URL-encode any that fall outside of the cookie range.

expires

httpOnly

note be careful when setting this to true, as compliant clients will not allow client-side JavaScript to see the cookie in document.cookie.

maxAge

path

sameSite

true will set the SameSite attribute to Strict for strict same site enforcement.
false will not set the SameSite attribute.
'lax' will set the SameSite attribute to Lax for lax same site enforcement.
'none' will set the SameSite attribute to None for an explicit cross-site cookie.
'strict' will set the SameSite attribute to Strict for strict same site enforcement.

note This is an attribute that has not yet been fully standardized, and may change in the future. This also means many clients may ignore this attribute until they understand it.

secure

note be careful when setting this to true, as compliant clients will not send the cookie back to the server in the future if the browser does not have an HTTPS connection.

Example

The following example uses this module in conjunction with the Node.js core HTTP server to prompt a user for their name and display it back on future visits.

var cookie = require('cookie');
var escapeHtml = require('escape-html');
var http = require('http');
var url = require('url');

function onRequest(req, res) {
  // Parse the query string
  var query = url.parse(req.url, true, true).query;

  if (query && query.name) {
    // Set a new cookie with the name
    res.setHeader('Set-Cookie', cookie.serialize('name', String(query.name), {
      httpOnly: true,
      maxAge: 60 * 60 * 24 * 7 // 1 week
    }));

    // Redirect back after setting cookie
    res.statusCode = 302;
    res.setHeader('Location', req.headers.referer || '/');
    res.end();
    return;
  }

  // Parse the cookies on the request
  var cookies = cookie.parse(req.headers.cookie || '');

  // Get the visitor name set in the cookie
  var name = cookies.name;

  res.setHeader('Content-Type', 'text/html; charset=UTF-8');

  if (name) {
    res.write('<p>Welcome back, <b>' + escapeHtml(name) + '</b>!</p>');
  } else {
    res.write('<p>Hello, new visitor!</p>');
  }

  res.write('<form method="GET">');
  res.write('<input placeholder="enter your name" name="name"> <input type="submit" value="Set Name">');
  res.end('</form>');
}

http.createServer(onRequest).listen(3000);

Testing

$ npm test

Benchmark

$ npm run bench

> cookie@0.3.1 bench cookie
> node benchmark/index.js

  http_parser@2.8.0
  node@6.14.2
  v8@5.1.281.111
  uv@1.16.1
  zlib@1.2.11
  ares@1.10.1-DEV
  icu@58.2
  modules@48
  napi@3
  openssl@1.0.2o

> node benchmark/parse.js

  cookie.parse

  6 tests completed.

  simple      x 1,200,691 ops/sec ±1.12% (189 runs sampled)
  decode      x 1,012,994 ops/sec ±0.97% (186 runs sampled)
  unquote     x 1,074,174 ops/sec ±2.43% (186 runs sampled)
  duplicates  x   438,424 ops/sec ±2.17% (184 runs sampled)
  10 cookies  x   147,154 ops/sec ±1.01% (186 runs sampled)
  100 cookies x    14,274 ops/sec ±1.07% (187 runs sampled)