官网链接：https://yarnpkg.com/lang/en/
特性
Ultra Fast.
Yarn caches every package it downloads so it never needs to download it again. It also parallelizes operations to maximize resource utilization so install times are faster than ever.
Mega Secure.
Yarn uses checksums to verify the integrity of every installed package before its code is executed.
Super Reliable.
Using a detailed, but concise, lockfile format, and a deterministic algorithm for installs, Yarn is able to guarantee that an install that worked on one system will work exactly the same way on any other system.
WHAT ARE YOU WAITING FOR?
Offline Mode
If you've installed a package before, you can install it again without any internet connection.
Deterministic
The same dependencies will be installed the same exact way across every machine regardless of install order.
Network Performance
Yarn efficiently queues up requests and avoids request waterfalls in order to maximize network utilization.
Same Packages
Install any package from npm and keep your package workflow the same.
Network Resilience
A single request failing won't cause an install to fail. Requests are retried upon failure.
Flat Mode
Resolve mismatching versions of dependencies to a single version to avoid creating duplicates.
Yarn is a package manager for your code.
It allows you to use and share code with other developers from around the world.
Yarn does this quickly, securely, and reliably so you don’t ever have to worry.
Yarn allows you to use other developers’ solutions to different problems, making it easier for you to develop your software.
If you have problems, you can report issues or contribute back, and when the problem is fixed, you can use Yarn to keep it all up to date.
Code is shared through something called a package (sometimes referred to as a module).
A package contains all the code being shared as well as a package.json file which describes the package.