autogenerate mobx-state-tree models from ruby mongoid models

doit.rb

def doit
  type_map = {
    BSON::ObjectId => 'string',
    Time => 'date',
    Object => 'reference',
    Hash => 'map',
    Integer => 'integer',
    DateTime => 'Date',
    String => 'string',
    Array => 'array',
    Time => 'Date',
    Mongoid::Boolean => 'boolean',
    Float => 'string',
  }

  Mongoid::Config.models.each_with_object({}) do |model, obj|
    name = model.model_name.name

    cat = "export const #{name} = types\n"
    cat << "  .model({\n"

    model.fields.each do |k, v|
      st_type = type_map[v.type]

      case v
      when Mongoid::Fields::ForeignKey
        cat << "    #{v.metadata.name}: types.reference(#{v.metadata.class_name}),\n"
      when Mongoid::Fields::Standard
        cat << "    #{v.name}: types.#{st_type},\n"
      else
        cat << "    #{v.name}: types.??,\n"
      end
    end

    cat << "  })\n"

    obj[name] = cat
  end
end