httpao/lib/outgoing.js

Simple, lighweight http server module

const dir = __dirname;
const {Socket} = require('net'),
      InComing = require(`${dir}/incoming.js`),
      Codes = require(`${dir}/codes.js`);

const validheader = (o) => {
   if (typeof o != 'object') throw new TypeError('The headers type must be a object');
};
const validheadername = (k) => {
   if (typeof k != 'string') throw new TypeError(`Header name must be a valid HTTP token ["${String(k)}"]`);
};
const validheadervalue = (k, v) => {
   if (typeof v == 'undefined') throw new TypeError(`Invalid value "${String(v)}" for header "${k}"`);
}
const validstatuscode = (c) => {
   if (typeof c != 'number' || c < 100 || c > 999) throw new Error(`Invalid status code: ${c}`);
};

const ksocket = Symbol('socket');
const kheadersSent = Symbol('headersSent');
const knoBody = Symbol('noBody');
const kheaders = Symbol('headers');
const kEnded = Symbol('Ended');

class OutGoing {
   constructor (socket, req) {
      if (!(socket instanceof Socket)) throw new TypeError('socket not a Socket instance');
      if (!(req instanceof InComing)) throw new TypeError('req not a InComing instance');
      this[ksocket] = socket;
      this[kheadersSent] = false;
      this[knoBody] = false;
      this[kheaders] = {};
      this[kEnded] = false;
   }

   write (d, e) {
      if (!this[kheadersSent]) {
         this._sendHeaders();
      }
      this[ksocket].write(d, e);
   }

   end (d, e) {
      this.write(d, e);
      this[ksocket].end();
      this[kEnded] = true;
   }

   setHeader (k, v) {
      if (this[kheadersSent]) throw new Error('Cannot set headers after they are sent to the client');
      validheadername(k);
      validheadervalue(k, v);
      this[kheaders][k] = String(v);
   }

   setHeaders (o) {
      validheaders(o);
      Object.keys(o).forEach(k => {
         this.setHeader(k, o[k]);
      });
   }

   writeHead (c, m, h) {
      validstatuscode(c);
      this.statusCode = c;
      if (m) {
         if (typeof m == 'string') {
            this.statusMessage = m;
         } else if (typeof m == 'object') {
            this.setHeaders(m);
            return;
         } else {
            throw new TypeError('The status message type must be a string');
         }
      }
      if (h) {
         this.setHeaders(h);
      }
      this._sendHeaders();
   }

   _sendHeaders () {
      this[kheadersSent] = true;
      this.statusCode = this.statusCode || 200;
      this.statusMessage = this.statusMessage ? this.statusMessage : (Codes[this.statusCode] ? Codes[this.statusCode] : this.statusCode);
      this[ksocket].write(`HTTP/1.1 ${this.statusCode} ${this.statusMessage}\r\n`);
      this[kheaders]['Date'] = new Date().toString();
      this[kheaders]['X-Powered-By'] = 'HTTPAO';
      Object.keys(this[kheaders]).forEach(k => {
         this[ksocket].write(`${k}: ${this[kheaders][k]}\r\n`);
      });
      this[ksocket].write(`\r\n`);
   }

   get headersSent () {
      return this[kheadersSent];
   }

   get Ended () {
      return this[kEnded];
   }

}

module.exports = OutGoing;