Design pattern for writing a list of filters for image uploading using node.js

I'm writing a simple image uploader in node.js and express 4. When the file is posted, the enclosed image will run through a series of filters:

• is this an acceptable MIME type? (jpg, gif, png, tiff)


• does this have a correspondingly acceptable extension?


• is this image less than 2 megabytes?


• has the file been truncated in the upload?

I'm used to doing this sort of thing in synchronous languages, where I would run the object through a series of if's, and return false if something catches. In javascript, however, the same approach will result in sending multiple headers.

I have gotten around this by nesting the filters in else clauses, but this is quickly becoming very unwieldy. This seems like a common design pattern, so what is the best way to handle something like this?

app.js:

var express     = require('express')
 ,  fs          = require('fs')
 ,  bodyParser  = require('body-parser')
 ,  serveStatic = require('serve-static')
 ,  multer      = require('multer')
 ,  port        = 80
 ;

var app = express();
app.set('views', __dirname + '/views');
app.set('view engine', 'jade');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(multer({ dest: "./images/tmp" }))
app.use(serveStatic(__dirname + '/public'));
app.listen(port);

app.get('/', function(req, res, next) {
    console.log(req);
    res.render("uploader");
});

var uploadConfig = {
    acceptedMimeTypes : [ "image/jpeg", "image/png", "image/gif", "image/tiff" ],
    acceptedExtensions : [ "jpg", "jpeg", "png", "gif", "tiff" ],
    maxFileSize : 2000000
};

app.post('/upload', function(req, res, next) {
    var image = req.files.image;
    var removeTempImage = function() {
        fs.unlink('images/tmp/' + image.name)
    };
   // Here is where things become a mess
    if (uploadConfig.acceptedMimeTypes.indexOf(image.mimetype) == -1) {
        removeTempImage();
        res.send({success: false, message: "Incorrect MIME type"});
    } else {
        if (uploadConfig.acceptedExtensions.indexOf(image.extension) == -1) {
            removeTempImage();
            res.send({success: false, message: "Incorrect file extension"});
        } else {
            if (image.size > uploadConfig.maxFileSize) {
                removeTempImage();
                res.send({success: false, message: "File is too large"});
            } else {
                if (image.truncated) {
                    removeTempImage();
                    res.send({success: false, message: "The file was truncated"});      
                } else {
                    // it survived the gauntlet
                    fs.rename('images/tmp/' + image.name, 'public/completeImgs/' + image.name, function (err) {
                        if (err) {
                            removeTempImage;
                            res.send({success: false, message: err});
                        } else {
                            res.send({success: true, message: "Your image has been saved"});
                        }
                    })
                }
            }
        }
    }
});


console.log("uploader is listening on port " + port);

uploader.jade

doctype
html
    head
    body
        h1 Image Uploader
        form(method="post" action="/upload" enctype="multipart/form-data")
            input(type="file" name="image")
            input(type="submit")
        h1 !{test}