Koa: Set up Chinese characters for cookies

[realjade]

this.cookies.set('test', '我是koajs')

sent error argument value is invalid to the cloud

TypeError: argument value is invalid
    at new Cookie (/Users/zyy/github/fete/node_modules/cookies/lib/cookies.js:110:11)
    at Cookies.set (/Users/zyy/github/fete/node_modules/cookies/lib/cookies.js:73:16)
    at Object.<anonymous> (/Users/zyy/github/fete/app.js:53:18)
    at next (native)
    at onFulfilled (/Users/zyy/github/fete/node_modules/co/index.js:65:19)
    at /Users/zyy/github/fete/node_modules/co/index.js:54:5
    at Object.co (/Users/zyy/github/fete/node_modules/co/index.js:50:10)
    at converted (/Users/zyy/github/fete/node_modules/koa-convert/index.js:17:15)
    at dispatch (/Users/zyy/github/fete/node_modules/koa-compose/index.js:43:32)
    at next (/Users/zyy/github/fete/node_modules/koa-compose/index.js:44:18)
    at createGenerator (/Users/zyy/github/fete/node_modules/koa-convert/index.js:24:16)
    at next (native)
    at onFulfilled (/Users/zyy/github/fete/node_modules/co/index.js:65:19)
    at /Users/zyy/github/fete/node_modules/co/index.js:54:5
    at Object.co (/Users/zyy/github/fete/node_modules/co/index.js:50:10)
    at Object.toPromise (/Users/zyy/github/fete/node_modules/co/index.js:118:63)

[PlasmaPower]

Valid HTTP header values (including cookies) are defined in RFC 7230 Section 3.2 to only include a limited selection of ASCII characters (not including Chinese characters). This is implemented in the NPM package cookies (used by Koa) here.

[dougwilson]

In order to include Chinese characters in cookie names of values, you just have to come up with an encoding scheme for the value. The cookies module just leaves this choice up to you, since there are various different methods of doing this (the two most popular being to use URL encoding of encoded octets or the base64 of come octets). A simple example of using URL encoding (where the characters are encoded as UTF-8):

this.cookies.set('test', encodeURIComponent('我是koajs'))

You can then read it back using the reverse:

decodeURIComponent(this.cookies.get('test'))