cookie

Basic HTTP cookie parser and serializer for HTTP servers.

# Installation

$ npm install cookie

# API

var cookie = require('cookie');

## cookie.parse(str, options)

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.

## cookie.serialize(name, value, options)

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

Specifies the value for the `Domain` `Set-Cookie` attribute. By default, no domain is set, and most clients will consider the cookie to apply to only the current 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 `ecodeURIComponent`, which will encode a JavaScript string into UTF-8 byte sequences and then URL-encode any that fall outside of the cookie range.

#### expires

Specifies the `Date` object to be the value for the `Expires` `Set-Cookie` attribute. By default, no expiration is set, and most clients will consider this a "non-persistent cookie" and will delete it on a condition like exiting a web browser application.

note the cookie storage model specification states that if both `expires` and `magAge` are set, then `maxAge` takes precedence, but it is possiblke not all clients by obey this, so if both are set, they should point to the same date and time.

#### httpOnly

Specifies the `boolean` value for the [`HttpOnly` `Set-Cookie` attribute][rfc-6266-5.2.6]. When truthy, the `HttpOnly` attribute is set, otherwise it is not. By default, the `HttpOnly` attribute is not set.

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

Specifies the `number` (in seconds) to be the value for the `Max-Age` `Set-Cookie` attribute. The given number will be converted to an integer by rounding down. By default, no maximum age is set.

note the cookie storage model specification states that if both `expires` and `magAge` are set, then `maxAge` takes precedence, but it is possiblke not all clients by obey this, so if both are set, they should point to the same date and time.

#### path

Specifies the value for the `Path` `Set-Cookie` attribute. By default, the path is considered the "default path". By default, no maximum age is set, and most clients will consider this a "non-persistent cookie" and will delete it on a condition like exiting a web browser application.

#### sameSite

Specifies the `boolean` or `string` to be the value for the `SameSite` `Set-Cookie` attribute.

- `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. -`'strict'`will set the`SameSite`attribute to`Strict` for strict same site enforcement.

More information about the different enforcement levels can be found in the specification https://tools.ietf.org/html/draft-west-first-party-cookies-07#section-4.1.1

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

Specifies the `boolean` value for the [`Secure` `Set-Cookie` attribute][rfc-6266-5.2.5]. When truthy, the `Secure` attribute is set, otherwise it is not. By default, the `Secure` attribute is not set.

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

# References

- RFC 6266: HTTP State Management Mechanism
- Same-site Cookies

# License

[MIT](LICENSE)