pnpm vs npm

npm 的平鋪資料夾結構#

npm maintains a flattened dependency tree. This leads to less disk space bloat, with a messy node_modules directory as a side effect.

On the other hand, pnpm manages node_modules by using hard linking and symbolic linking to a global on-disk content-addressable store. This lets you get the benefits of far less disk space usage, while also keeping your node_modules clean. There is documentation on the store layout if you wish to learn more.

The good thing about pnpm's proper node_modules structure is that it "helps to avoid silly bugs" by making it impossible to use modules that are not specified in the project's package.json.

安裝#

pnpm does not allow installation of packages without saving them to package.json. If no parameters are passed to pnpm add, packages are saved as regular dependencies. Like with npm, --save-dev and --save-optional can be used to install packages as dev or optional dependencies.

由於此限制，專案在使用 pnpm 時不會有任何無關的套件，除非它們刪除依賴項並將其保留為孤立的。 That's why pnpm's implementation of the prune command does not allow you to specify packages to prune - it ALWAYS removes all extraneous and orphaned packages.

資料夾依賴#

A directory dependency points to a directory in the filesystem. pnpm handles it according to its protocol:

• link: (also recorded by pnpm add ./dir) symlinks the directory into node_modules. pnpm does not install the directory's own dependencies.
• file: copies the directory into the virtual store as a package and installs its dependencies like any other package.

For example, if a package called foo (<root>/foo) has bar@link:../bar as a dependency, pnpm does not install the dependencies of <root>/bar when you run pnpm install on foo.

If you need to run installations in several packages at the same time, for instance in the case of a monorepo, you should look at the documentation for pnpm -r.