Yarn – A new package manager for JavaScript

I have no idea if you're familiar with the java ecosystem, but I am, so I'll use that as an example:

Node libraries are typically several orders of magnitude smaller and more single purpose than java libraries. Java libraries like Guava and Spring are typically quite large. A practical example is from unit testing: In Java, you might use JUnit+Mockito for your test dependencies. In Node, to get similar functionality, I have the following deps: Mocha, Sinon, Sinon-As-Promised, Chai, Chai-Moment, Chai, Chai-Things, Chai-Shallow-Deep-Equal, Chai-Datetime, Sinon-Express-Mock, Supertest.

Many Javascript applications both client and server functionality, and there is different tooling for both. Webpack is currently popular for building stuff that will run in the browser, whereas server side stuff is different.

It's a much newer technology than java and there is quite a lot of churn around tooling in general as the nature of the way applications are built change.

It is quite a congenial response and no disrespect to npm inc, but yarn will be technically far superior (if it's not already), and I can't help but interpret this as the beginning of the end for npm....It was only a matter of time though since there are a number of systemic problems with npm and (in my opinion) it is at the center of the dysfunctional world of modern JavaScript tooling. It did move the ecosystem forward significantly for a number of years, but now something better is required. Sorry to be blunt, just my opinion.

browser incompatibility is the biggest issue (if not the only issue). this is almost a non-issue if you're just writing node related programs. but if you need to support in the browser, now you have edge, chrome, firefox, and safari at minimum. then some have to continue supporting ie10/ie11, or even worse, ie7+.

don't forget about mobile devices, with ios having such a difficult-to-write-anything-new version of mobile safari.

i'm writing a new app for myself, so i don't have to worry about any backwards compatibility issues, except it needs to work on my iphone, which uses mobile safari webviews, which means i have to either use shims or restrict myself back to es5, non-html5 features (or work around their html5 limitations).

example: you cannot cache audio files to play using tags in mobile safari. safari just refetches it from your server (also has to recreate the audio object, which causes a lag in the audio being played). technically you _can_ cache if you convert all your audio files to base64 and use the webaudio api. i'm probably going to have to go this route because i'd like the app to be offline usable.

so rather than spend time on my app, i now have to write out a build step for converting audio to base64. then test that it works fine in ios and desktop browsers (at least chrome, firefox). it all just keeps adding up.

I'm really liking yarn. It solves some of my main issues with npm, it's fast and it provides some great output in the CLI. It's also architected absolutely ingeniously. Seriously they have positioned themselves to seamlessly take over npm's entire business just like that. What do I mean?

So today by default yarn goes through its servers which then proxy to npm's. As time goes Facebook can add more features to its own repo (custom submissions instead of to npm or maybe it does a federated publish to both at first, nice looking pages with community engagement tools built in, better metrics (npm provides me with almost worthless metrics), etc). Then when enough people are using Yarn Facebook could simply...flip the switch. Then boom, zero npm usage.

I would be terrified if I were NPM right now. They've sat on their hands for years not improving npm. I mean npm3 had a silly CLI animation that made all downloads take orders of magnitude longer simply because of the animation!

P.S. if you're trying to use yarn with a custom npm repository just drop a .yarnrc file into your project's directory then add the following in that file:

registry "http:// register>"

I'm very excited about this. Private package support is a must-have for it to get any traction in my company. We are more than ready to leave shrinkwrap behind.