例外処理をまとめる

[ofl]

• API、GraphQLで共通するエラーを定義
• エラーログの処理の共通化

Railsアプリケーションにおけるエラー処理（例外設計）の考え方 RailsでAPIをつくるときのエラー処理

【Rails】独自例外の置き場所（配置ディレクトリ）について RailsでAPIを作るときのエラー処理について rubyでエラーコード付きの独自例外クラスを作成 + カスタムloggerで出力

[ofl]

Error -> symbol Rails.application.config.action_dispatch.rescue_responses

symbol -> status_code Rack::Utils::SYMBOL_TO_STATUS_CODE

[ofl]

{"error":{"latitude":["is not a number"],"longitude":["is not a number"]}}

Handling Errors in an API Application the Rails Way

Providing useful error responses in a Rails API

Building APIs with Rails: Handling Errors Nicely

{
  "errors": [
    {
      "source": {
        "pointer": "/data/attributes/name"
      },
      "detail": "can't be blank"
    },
    {
      "source": {
        "pointer": "/data/attributes/description"
      },
      "detail": "can't be blank"
    }
  ]
}

How to Build Rails APIs Following the json:api Spec

{
  errors: [
    status: 422,
    source: {pointer: "/data/attributes/rooms"},
    detail: "Must be present."
  ]
}

Jsonapi errorable

{
  errors: [
    {
      code: 'unprocessable_entity',
      status: '422',
      title: 'Validation Error',
      detail: "Title can't be blank",
      source: { pointer: '/data/attributes/title' },
      meta: {
        attribute: 'title',
        message: "can't be blank"
        code: 'blank'
      }
    }
  ]
}

{
  errors: [
    {
      code: 'unprocessable_entity',
      status: '422',
      title: 'Validation Error',
      detail: "Body can't be blank",
      source: { pointer: '/data/attributes/body' },
      meta: {
        relationship: {
          attribute: 'body',
          message: "can't be blank"
          code: 'blank'
          id: '123',
          type: 'comments'
        }
      }
    }
  ]
}

[ofl]

https://github.com/Netflix/fast_jsonapi/issues/53

class ErrorSerializer
  def initialize(model)
    @model = model
  end

  def serialized_json
    errors = @model.errors.messages.map do |field, errors|
      errors.map do |error_message|
        {
          source: {pointer: "/data/attributes/#{field}"},
          detail: error_message
        }
      end
    end
    @model.class.reflect_on_all_associations.each do |relationship|
      @model.send(relationship.name).each_with_index do |child, index|
        errors << child.errors.messages.map do |field, errors|
          errors.map do |error_message|
            {
              source: {pointer: "/data/attributes/#{child.model_name.plural}[#{index}].#{field}"},
              detail: error_message
            }
          end
        end
      end
    end
    errors.flatten
  end
end