Hi @shilman, I'd like to pick this issue up if possible.

Currently the cli doesn't add peerDependencies for any of the supported frameworks/templates so theoretically this issue could arise for any supported framework, although this is pretty unlikely that this would ever cause an issue if storybook is being added to an existing project but i suppose it could be an issue if storybook were being added at the same time a project is created (maybe I'm clutching at straws a bit there).

It would probably be worth adding handling for peerDependencies for all frameworks/templates, there is one caveat to this though as not all versions of npm will install missing peerDependencies and yarn doesn't install them at all.

npm versions 1, 2, and 7 will automatically install peerDependencies if they are not explicitly depended upon higher in the dependency tree. For npm versions 3 through 6, you will receive a warning that the peerDependency is not installed instead.
Ref: https://nodejs.org/en/blog/npm/peer-dependencies/

So the best solution would probably be to have some handling that maps the peerDependencies required for a given framework/template into devDependencies when we generate the package.json, assuming this wouldn't cause any undesirable side effects.

Do you have any thoughts on this approach @shilman?

@ben-m-j-taylor Thanks for taking this on! 🙏

I don't think it needs to take any of the frameworks on as peer dependencies since it doesn't actually USE any of them. It installs packages into the user's project, but that's not the same thing as relying on any of the functionality/code from the package. cc @gaetanmaisse

Hey @shilman, sorry for the slow reply!

Yes, you're right, I think my mental model of how this was all working had gotten a bit spun around.

So really what we want to do is take what storybook is listing as a peer dependency for a given template/framework and if it isn't already installed in the project we should add it as a dependency and install it.

So for @storybook/web-components which has the following peer dependencies in its package.json:

{
  "name": "@storybook/web-components",
  "version": "6.4.0-alpha.32",
  ...
  "peerDependencies": {
    "lit-html": "^1.4.1 || ^2.0.0-rc.3"
  },
  ...
}

We would need to ensure that lit-html is a dependency of the initialised project if they were to run npx sb init --type web_components.