我遇到一个问题，在此应用程序上尝试POST请求时收到以下错误代码（请记住我是初学者node.js / js程序员）：

错误：

[20:22:28] [nodemon] starting `node app.js`
Running server on 3000
Mon, 27 Jun 2016 19:22:31 GMT express deprecated res.send(status, body): Use res.status(status).send(body) instead at routes\edit.js:35:25
c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\mongodb\lib\utils.js:98
    process.nextTick(function() { throw err; });
                                  ^

RangeError: Invalid status code: 0
    at ServerResponse.writeHead (_http_server.js:192:11)
    at ServerResponse._implicitHeader (_http_server.js:157:8)
    at ServerResponse.OutgoingMessage.end (_http_outgoing.js:573:10)
    at ServerResponse.send (c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\express\lib\response.js:204:10)
    at ServerResponse.json (c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\express\lib\response.js:249:15)
    at ServerResponse.send (c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\express\lib\response.js:151:21)
    at c:\Users\Matt\WebstormProjects\ghs_restart\routes\edit.js:35:25
    at c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\mongodb\lib\collection.js:416:18
    at handleCallback (c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\mongodb\lib\utils.js:96:12)
    at c:\Users\Matt\WebstormProjects\ghs_restart\node_modules\mongodb\lib\collection.js:705:5

app.js：

var express = require('express');

var router = express.Router();

var app = express();

var bodyParser = require('body-parser');
app.use( bodyParser.json() );       // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({     // to support URL-encoded bodies
    extended: true
}));

var path = require('path');

var port = process.env.PORT || 3000;

var index = require('./routes/index');
var edit = require('./routes/edit');

app.use('/', index);
app.use('/edit', edit);

app.use(express.static(path.join(__dirname, 'public')));

app.set('view engine', 'jade');

app.set('views', 'views');

app.listen(port, function (err) {
    console.log("Running server on", port);
});

module.exports = index;

以下是我的edit.js路由，我认为是发生问题的地方：

var express = require('express');

var router = express.Router();

var app = express();

var bodyParser = require('body-parser');
app.use( bodyParser.json() );       // to support JSON-encoded bodies
app.use(bodyParser.urlencoded({     // to support URL-encoded bodies
    extended: true
}));

var path = require('path');

var port = process.env.PORT || 3000;

var index = require('./routes/index');
var edit = require('./routes/edit');

app.use('/', index);
app.use('/edit', edit);

app.use(express.static(path.join(__dirname, 'public')));

app.set('view engine', 'jade');

app.set('views', 'views');

app.listen(port, function (err) {
    console.log("Running server on", port);
});

module.exports = index;