Node.js Service Registry

Question

 register(name, version, ip, port) {
 this.cleanup();
 const key = name + version + ip + port;
 if (!this.services[key]) {
 this.services[key] = {};
 this.services[key].timestamp = Math.floor(new Date() / 1000);
 this.services[key].ip = ip;
 this.services[key].port = port;
 this.services[key].name = name;
 this.services[key].version = version;
 this.log.debug(`Added services ${name}, version ${version} at ${ip}:${port}`);
 return key;
 }
 this.services[key].timestamp = Math.floor(new Date() / 1000);
 this.log.debug(`Updated services ${name}, version ${version} at ${ip}:${port}`);
 return key;
 }

I thought the code looked kinda amateurish. I am not sure if I am imagining things. Isn't there a better way to assign values, also what about how the key is made, shouldn't we use a random string generator or at least encode it after appending the values? What's the best practice?

https://github.com/bluebrid/base-knowledge/blob/317bcdacd3a3806a6f98f05a7660dc97c506e8fb/javascript/advance/microservices/demo.1/service-registry/server/lib/ServiceRegistry.js

Answer 1

The code is pretty clear, I wouldn't call amateurish. Some cleanup could be done, though.

Avoid duplication

The timestamp code is duplicated, you could create a function for it:

const getTimestamp = () => {
 return Math.floor(new Date() / 1000)
}

You'll see below I refactored the register method to only set the timestamp once, but this still holds as a general recommendation: don't repeat the same code.

String building

Personally I prefer to use the backtick to build strings from variables:

const alpha = 'alpha';
const bravo = 'bravo';
const key = `${alpha}${bravo}`;

Assignment shorthand

ES6 provides a shorthand for object property assignment. If a key has the same name as a variable passed in as a property, you only need to specify the key name. Your service object is a perfect candidate for this:

register(name, version, ip, port) {
 this.cleanup();
 const key = `${name}${version}${ip}${port}`;
 let operation = 'Updated'
 if (!this.services[key]) {
 operation = 'Added'
 this.services[key] = {
 name, version, ip, port
 };
 }
 this.services[key].timestamp = Math.floor(new Date() / 1000);
 this.log.debug(`${operation} services ${name}, version ${version} at ${ip}:${port}`);
 return key;
}