RFC: ReactFiberReconciler release artifact

[iamdustan]

This issue is intended to be a discussion for how to distribute the ReactFiberReconciler.js file and dependencies for custom renderers.

Currently first-class renderers within the React codebase/Facebook ecosystem do not have any concerns for this because of Haste / access to the React.js build + publish tooling within this codebase.

3rd party renderers are currently adding react-dom to their dependency list and requiring react-dom/lib/ReactFiberReconciler.js to build and expose their custom renderer.

Ideally, ReactFiberReconciler.js would be distributed with the react package or as a standalone react-fiber-reconciler package. Whether this is at react/reconciler.js or react/lib/reconciler.js idk. I think at the root is better to continue the discouragement of looking in react/lib/* for anything.

I understand flat bundles are coming, too. I don’t know if that should block this or if this could be a flat bundle, or any other alternative.

Is this something the team is ready to commit to and support if we came to a decision on approach and I put together a PR?

Related issues:

• Create Separate Copies of Each Renderer #6795 Create Separate Copies of Each Renderer
• Include flow type definitions #5472 Include flow type definitions (flow type distribution proposal at Include flow type definitions #5472 (comment))

• @sebmarkbage @spicyj

[sebmarkbage]

Here's how I see the goal repo layout to be:

1. Lerna style repo layout.
2. One package is the reconciler core which react-dom etc. depend on. It will be a separate package like react-something-reconciler. (Not react since that doesn't let renderers release new versions separately without being in lock-step with the main package.)
3. For packages like react-dom we'll only depend on react-something-reconciler as a devDependency.
4. In prepublish for react-dom we'll actually compile a bundled (flat bundle) copy e.g. with Rollup. That includes the entirety of react-something-reconciler but allows us to DCE and inline renderer specific pieces.

Now other renderers can have strong dependencies on react-something-reconciler but I'm not sure we'll fully support that dependency being shared outside of devDependencies since it might have global state that is not safe to share with two renderers at the same time. Compiling it into a single package avoids that problem.

[gaearon]

We could also expose our build tooling (Rollup + DCE toolchain) as a build-time dependency (just like react-scripts from Create React App). This way we could share the same setup between our and third-party renderers.

[gaearon]

Basically, this:

mkdir my-renderer
cd my-renderer

npm init -y
npm install --save-dev react-renderer-scripts

edit hostConfig.js # write your renderer

./node_modules/react-renderer-scripts build ./hostConfig.js

# produces UMDs:
#   build/my-react-renderer.js
#   build/my-react-renderer.min.js

[iamdustan]

Awesome. Thanks Sebastian and Dan.

Is react-renderer-scripts a future step or intended to be in the initial publishing?

Are there any blocking issues that need to land before this can be tackled?

[gaearon]

That's just a wild suggestion, I don't know if we're going to do it this way or not.
We're going to start working on flat bundle infra next week with @trueadm so we'll keep you posted.

[kenwheeler]

How would it work if you wanted to still use some of ReactDOM's internals, but switch things up a little? Just fork it?

[gaearon]

Yea.

[drom]

Any progress on the issue?
It is well desired feature, one way or another.

[gaearon]

No, if there was progress it would be on this issue :-)
If you have ideas on how to make it work or want to give it a try please feel free to!

[xaviervia]

Is it reasonable to build renderers using the ReactFiberReconciler from alpha.3? It’s fine if it’s unstable, just wondering if there is a final decision on whether the reconciler will be supported as a public API at some point.

[gaearon]

It will be supported as public API, we just haven't decided how to expose it. It's okay to use an old exposed version in the meantime.