To put it simply: React Native makes assumptions that rely on the existence of the node_modules folder. For this reason, PnP is also referred to as ‘Zero-Installs’. Now that we have a repository where our dependencies are committed, there’s no need to run yarn install when switching branches or checking out a project.

We shouldn’t ever commit our node_modules folder due to its size and complexity ( and all these other reasons), but committing these zip files is simple: one file per dependency. pnp.js contains the ‘magic’ that allows node to read dependencies from this new structure. Instead, each direct and transitive dependency is compressed into a zip file, then stored in. In PnP, we don’t have a node_modules folder. When we run yarn install, the full dependency tree is recreated using files and folders, and stored in a folder named node_modules. This tree structure is stored in yarn.lock to prevent different versions of the package manager from creating a different tree, which could cause all sorts of unexpected behaviour. It’s normal for each dependency to have many of its own dependencies, forming a ‘dependency tree’. However, our depedencies can also have their own dependencies. In Classic Yarn (and npm), we define our dependencies in a manifest file named package.json.

This article will explain what PnP is, why React Native does not support it, and how we can work around this to enjoy most the advantages of Yarn 3. However, React Native is one of the only notable projects that doesn’t support PnP, and that’s unlikely to change soon. One of its most notable features is Plug-n-Play (hereafter ‘PnP’), a radical new approach to dependency management that removes the need to run yarn install and ditches the node_modules folder. Yarn Berry (aka Modern Yarn or Yarn 2+) is a replacement for Classic Yarn that offers performance improvements, better support for workspaces, and a cleaner developer experience.

Zero install yarn