Generate a `.zed/settings.json` file from `.editorconfig`

editorconfig2zedsetting.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true, quiet: 1) do
  source "https://rubygems.org"
  gem "editorconfig"
end

require "json"

config, _root = EditorConfig.parse(File.read(".editorconfig"))

LANGS = {
  "*.sh" => "Shell Script", "*.bash" => "Shell Script", "*.zsh" => "Shell Script",
  "*.rb" => "Ruby",
  "*.json" => "JSON",
  "*.js" => "JavaScript",
  "*.c" => "C", "*.h" => "C", "*.[ch]" => "C", "*.[hc]" => "C",
  "*.cc" => "C++", "*.cpp" => "C++",
  "*.py" => "Python",
}

CONFIG_NAME_MAP = {
  "indent_style" => {
    key: "hard_tabs",
    value: proc { _1 != "true" }
  },
  "indent_size" => {
    key: "tab_size",
    value: proc { _1 }
  },
  "insert_final_newline" => {
    key: "ensure_final_newline_on_save",
    value: proc { _1 == "true" }
  },
  "trim_trailing_whitespace" => {
    key: "remove_trailing_whitespace_on_save",
    value: proc { _1 == "true" }
  },
}

settings = {}

def append_settings(settings, conf)
  conf.each do |key, value|
    if CONFIG_NAME_MAP.key?(key)
      newkey = CONFIG_NAME_MAP[key][:key]
      newvalue = CONFIG_NAME_MAP[key][:value].call(value)
      settings[newkey] = newvalue
    else
      raise "Unhandled config: #{key}"
    end
  end
end

config.each do |section, conf|
  if section == "*"
    append_settings(settings, conf)
  elsif LANGS.key?(section)
    lang = LANGS[section]
    settings["language_overrides"] ||= {}
    settings["language_overrides"][lang] ||= {}
    append_settings(settings["language_overrides"][lang], conf)
  else
    raise "Unhandled pattern: #{section}"
  end
end

Dir.mkdir(".zed")
File.write(".zed/settings.json", JSON.pretty_generate(settings))