mgrading/babel-core/README.md

babel-bridge

This repo holds what we're calling a "bridge" package that is meant to ease the transition for libraries that use "babel-core" as a peer dependency for Babel 6.

The issue with Babel 7's transition to scopes is that if a package depends on Babel 6, they may want to add support for Babel 7 alongside. Because Babel 7 will be released as @babel/core instead of babel-core, maintainers have no way to do that transition without making a breaking change. e.g.

peerDependencies: {
  "babel-core": "6.x"
}

cannot change to

peerDependencies: {
  "@babel/core": "6.x"
}

without it being a breaking change.

Solution

To address this, we're releasing this bridge package, to allow users to do

peerDependencies: {
  "babel-core": "6.x | ^7.0.0-bridge"
}

then where users of this package would originally have done

npm i some-package babel-core

to install Babel 6, they could now do

npm i some-package babel-core@^7.0.0-bridge @babel/core

to install the bridge package, and install Babel 7's core.