Keep to DRY in declaring HTTP and HTTPS REST server

Question

I am using node.js Restify v4.0.3. The REST API server supports HTTP and HTTPS. Currently, the code for declaring the servers violates the DRY (don't repeat yourself) principle.

Declaration code for HTTP server.

var server = restify.createServer({
    name: 'myapp',
    version: '1.0.0'
});
server.use(restify.acceptParser(server.acceptable));
server.use(restify.queryParser());
server.use(restify.bodyParser());

server.use(restify.CORS());
server.opts(/.*/, function (req,res,next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", req.header("Access-Control-Request-Method"));
    res.header("Access-Control-Allow-Headers", req.header("Access-Control-Request-Headers"));
    res.send(200);
    return next();
});

server.listen(8400, function () {
    console.log('%s listening at %s', server.name, server.url);
});

Declaration code of HTTPS server

var https_options = {
    name: 'myapp',
    version: '1.0.0',
    key: fs.readFileSync('./HTTPS.key'), //on current folder
    certificate: fs.readFileSync('./HTTPS.cert'),
};

var https_server = restify.createServer(https_options);

https_server.use(restify.acceptParser(server.acceptable));
https_server.use(restify.queryParser());
https_server.use(restify.bodyParser());

https_server.use(restify.CORS());
https_server.opts(/.*/, function (req,res,next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", req.header("Access-Control-Request-Method"));
    res.header("Access-Control-Allow-Headers", req.header("Access-Control-Request-Headers"));
    res.send(200);
    return next();
});

https_server.listen(8500, function () {
    console.log('%s listening at %s', https_server.name, https_server.url);
});

There is quite a bit of repetition. How can the code be improved to conform to DRY principle?

CaptainAdams · Accepted Answer · 2015-11-13T05:38:16.143

You could place all the .use calls in a single setupDependencies call and all the header setting in a single setHeaders call.

var https_options = {
    name: 'myapp',
    version: '1.0.0',
    key: fs.readFileSync('./HTTPS.key'), //on current folder
    certificate: fs.readFileSync('./HTTPS.cert'),
};

var https_server = restify.createServer(https_options);

https_server.use(restify.acceptParser(server.acceptable));
https_server.use(restify.queryParser());
https_server.use(restify.bodyParser());

https_server.use(restify.CORS());
https_server.opts(/.*/, function (req,res,next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", req.header("Access-Control-Request-Method"));
    res.header("Access-Control-Allow-Headers", req.header("Access-Control-Request-Headers"));
    res.send(200);
    return next();
});

Would reduce to:

var https_options = {
    name: 'myapp',
    version: '1.0.0',
    key: fs.readFileSync('./HTTPS.key'), //on current folder
    certificate: fs.readFileSync('./HTTPS.cert'),
};

var https_server = restify.createServer(https_options);

setupDependencies(https_server);

https_server.opts(/.*/, function (req,res,next) {
    setHeaders(req, res);
    res.send(200);
    return next();
});


/* helpers */

function setupDependencies(server) {
    server.use(restify.acceptParser(server.acceptable));
    server.use(restify.queryParser());
    server.use(restify.bodyParser());
    server.use(restify.CORS());
};

function setHeaders(req, res) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", req.header("Access-Control-Request-Method"));
    res.header("Access-Control-Allow-Headers", req.header("Access-Control-Request-Headers"));
};

Keep to DRY in declaring HTTP and HTTPS REST server

1 Answers1