yarn2nix and peerDependencies

[dhess]

If a Node.js package has peerDependencies in its package.json, yarn2nix doesn't install these dependencies when building the package. These should be installed during the package build process. For example, imagine you're designing a React library that exports some bespoke React components. It's typical in this case to list "react" and "react-dom" as peerDependencies, meaning that they'll be installed for local development and testing (and for things like Storybook.js), but not in the published package, as peerDependencies are supposed to be installed by the downstream consumer of the package.

Therefore, according to my understanding, yarn2nix should be installing peerDependencies prior to the buildPhase, in case the user overrides the default buildPhase, or adds a postBuild step that runs, e.g., yarn --offline build. As it stands, such phases will break due to the missing dependencies.

[dhess]

I'm surprised nobody else has jumped on this or indicated that it's a problem for them, as well. Perhaps I'm doing something wrong? How are people who're using yarn2nix dealing with this issue? It's particularly relevant to React projects that use separate component packages, as far as I can tell.