express中创建 websocket 接口及问题解答

const express = require(`express`)
const server = express()
const expressWs = require(`express-ws`)
expressWs(server)

server.ws(`/aaa`, (ws, req) => {
  console.log(`socket`, req.testing)
  ws.send(`aaa`)
  ws.on(`message`, function(msg) {
    console.log(msg)
  })
})
server.get(`/bbb`, (req, res) => {
  res.json(`bbb`)
})
server.listen(3040)

function expressWs(app, httpServer, options = {}) {
  addWsMethod(app)
  const server = http.createServer(app)
  app.listen = function serverListen(...args) {
    return server.listen(...args)
  }
  const wsServer = new ws.Server({server})
  wsServer.on(`upgrade`, async (req, socket, upgradeHead) => {
    const res = new http.ServerResponse(req)
    return server(req, res)
  })
  wsServer.on(`connection`, (socket, request) => {
    if (`upgradeReq` in socket) {
      request = socket.upgradeReq
    }
    request.ws = socket
    request.wsHandled = false
    request.url = websocketUrl(request.url)
    const dummyResponse = new http.ServerResponse(request)
    dummyResponse.writeHead = function writeHead(statusCode) {
      if (statusCode > 200) {
        dummyResponse._header = `` // eslint-disable-line no-underscore-dangle
        socket.close()
      }
    }
    app.handle(request, dummyResponse, () => {
      if (!request.wsHandled) {
        socket.close()
      }
    })
  })
}

function trailingSlash(string) {
  let suffixed = string
  if (suffixed.charAt(suffixed.length - 1) !== `/`) {
    suffixed = `${suffixed}/`
  }
  return suffixed
}


function websocketUrl(url) {
  if (url.indexOf(`?`) !== -1) {
    const [baseUrl, query] = url.split(`?`)
    return `${trailingSlash(baseUrl)}.websocket?${query}`
  }
  return `${trailingSlash(url)}.websocket`
}


function addWsMethod(target) {
  if (!target.ws) {
    target.ws = function (route, ...middlewares) {
      const wrappedMiddlewares = middlewares.map((function (middleware) {
        return (req, res, next) => {
          if (req.ws) {
            req.wsHandled = true
            try {
              middleware(req.ws, req, next)
            } catch (err) {
              next(err)
            }
          } else {
            next()
          }
        }
      }))
      const wsRoute = websocketUrl(route)
      this.get(...[wsRoute].concat(wrappedMiddlewares))
      return this
    }
  }
}

import { createServer } from 'http';
import { parse } from 'url';
import { WebSocketServer } from 'ws';

const server = createServer();
const wss1 = new WebSocketServer({ noServer: true });
const wss2 = new WebSocketServer({ noServer: true });

wss1.on('connection', function connection(ws) {
  // ...
});

wss2.on('connection', function connection(ws) {
  // ...
});

server.on('upgrade', function upgrade(request, socket, head) {
  const { pathname } = parse(request.url);

  if (pathname === '/foo') {
    wss1.handleUpgrade(request, socket, head, function done(ws) {
      wss1.emit('connection', ws, request);
    });
  } else if (pathname === '/bar') {
    wss2.handleUpgrade(request, socket, head, function done(ws) {
      wss2.emit('connection', ws, request);
    });
  } else {
    socket.destroy();
  }
});

server.listen(8080);

function expressWs(app) {
  const server = http.createServer(app)
  server.on(`upgrade`, (req, socket, head) => {
    const obj = app.wsRoute[req.url]
    obj ? obj.wss.handleUpgrade(req, socket, head, ws => obj.mid(ws, req)) : socket.destroy()
  })
  app.listen = (...arg) => server.listen(...arg)
  app.ws = (route, mid) => {
    app.wsRoute = app.wsRoute || {}
    app.wsRoute[route] = {
      wss: new Server({ noServer: true }),
      mid,
    }
  }
}

const express = require(`express`)
const server = express()
expressWs(server)

server.ws(`/aaa`, (ws, req) => {
  console.log(`socket`, req.testing)
  ws.send(`aaa`)
  ws.on(`message`, function(msg) {
    console.log(msg)
  })
})
server.get(`/bbb`, (req, res) => {
  res.json(`bbb`)
})
server.listen(3040)