babel-upgrade

babel-upgrade

npx babel-upgrade

Goals

Update dependencies, config file, files that require babel directly

• auto run npm or yarn
• Update package.json: dependencies and devDependencies to the "latest supported" version.
  • This includes doing all package renames
  • This includes upgrading the same package to the latest version
  • add @babel/core peerDep
  • modify scripts for mocha + @babel/register
  • throw/warn if engines is < node 4 or current node is < 4?
  • log when replacing out preset-es2015,16,17,latest as FYI
  • if babel-node is used, import @babel/node?
• Update the babel config file(s).
  • .babelrc
  • .babelrc.js
  • package.json babel key
  • handle env
  • handle shorthand names: babel-preset-env and env
  • convert comma separated presets/plugins into an array
  • handle react + flow preset being split. Read if .flowconfig and add it?
  • convert only/ignore?
  • how do we want to handle spec/loose modes, especially when changing previous loose mode to spec (just warn?)
  • remove typeof-symbol if using @babel/preset-env
• Update test files that use babel directly (babel-types, babel-core)
  • Update all requires/imports
  • Update the use of the Babel API (plugins, integrations)
• Misc files as we go (karma.conf.js, mocha.opts)
• Add to the upgrade guide which parts are autofixable and the command (if we care enough to make this individually runnable too infrastructure wise)
• May need to add a warning on any 3rd party plugins since they might not be compatible
• later: work on node 4
• Should certain parts be generic (replace the string babel-register with @babel/register)? Could be in a Makefile or somewhere else, but it's just find replace.

Philosophy

• Move this into the monorepo when somewhat ready
  • Maybe move into @babel/cli?
  • Or just another package that is intended to be used via npx/globally
• Whenever there is a breaking change in a PR we should also update this tool when possible or at least provide a warning
  • What about with a regression?
• Can be used for non-major bumps too - just for updating to the latest version.
• Include mini-changelog?
• Maybe the version should just reflect the version that it targets?