react.rb

require "webpacker/configuration"

babelrc = Rails.root.join(".babelrc")
babel_react_preset = ["@babel/preset-react", { "useBuiltIns": true }]

if File.exist?(babelrc)
  react_babelrc = JSON.parse(File.read(babelrc))
  react_babelrc["presets"] ||= []

  unless react_babelrc["presets"].flatten.include?("@babel/preset-react")
    react_babelrc["presets"].push(babel_react_preset)
    say "Copying react preset to your .babelrc file"

    File.open(babelrc, "w") do |f|
      f.puts JSON.pretty_generate(react_babelrc)
    end
  end
else
  say "Copying .babelrc to app root directory"
  copy_file "#{__dir__}/examples/react/.babelrc", ".babelrc"
end

say "Copying react example entry file to #{Webpacker.config.source_entry_path}"
copy_file "#{__dir__}/examples/react/hello_react.jsx", "#{Webpacker.config.source_entry_path}/hello_react.jsx"

say "Updating webpack paths to include .jsx file extension"
insert_into_file Webpacker.config.config_path, "- .jsx\n".indent(4), after: /extensions:\n/

say "Installing all react dependencies"
run "yarn add react react-dom @babel/preset-react prop-types"

say "Webpacker now supports react.js 🎉", :green