Expose Babel config for Gatsby

Summary

Exposing Gatsby’s Babel configuration would allow Gatsby apps to integrate with 3rd party tooling like linters and testing frameworks. There are two options for accomplishing this, making Gatsby’s config a babel preset, or printing a .babelrc file in root of project (or somewhere else).

Motivation

Currently getting testing or linting configuration requires essentially copying what Gatsby does into your own .babelrc file, at this point it would be much cleaner and easier on the user to just install and include babel-preset-gatsby.

[Tomekmularczyk]

Yeah, same here. Some tools require babel-config available like babel-plugin-react-intl. The same if I wanted to create my own tool that relies on babel and I don’t necessarily want it in my build system (by extending webpack config).

I see that most of examples and even documentation suggests copying specific presets and plugins. But this is less than optimal and more like a workaround I believe. It will make harder to migrate app to newer versions. Specifying packages in config that are not installed explicitly by user is also fragile I think.

What I would ideally see is something like they do in NextJS. If you want a custom .babelrc you create a file with a nextjs preset which has all that is necessary to work by a framework:

.babelrc

{
  "presets": [
    "next/babel"
  ]
  ...
}

[kkemple]

Yeah, I think it makes sense expose it as a preset so it’s really easy to configure with tooling. I hit issues with Storybook as well.