npm install yarn -g
配置好离线镜像后，Yarn将自动添加新程序包的压缩包 (tarball) 到镜像 但是，它不会自动移除不再在
yarn.lock 中提到的压缩包。 For example, if you
$ yarn remove a dependency, the tarball will remain in the mirror, even if no other dependencies have it as a sub-dependency. This behavior can be desirable in a setting where many projects share the same mirror, but when that is not the case, you may want to have Yarn remove unnecessary tarballs.
To turn on automating pruning, set
true in your
$ yarn config set yarn-offline-mirror-pruning true
Now, tarballs will be removed when appropriate. The end result is that
yarn.lock, and the offline mirror should all remain perfectly in sync whenever you change your project’s dependencies.