From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-3.6 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id BBD7A1F453 for ; Wed, 1 May 2019 17:09:42 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 6024B120ADF; Thu, 2 May 2019 02:09:37 +0900 (JST) Received: from o1678948x4.outbound-mail.sendgrid.net (o1678948x4.outbound-mail.sendgrid.net [167.89.48.4]) by neon.ruby-lang.org (Postfix) with ESMTPS id D307B120ABA for ; Thu, 2 May 2019 02:09:34 +0900 (JST) Received: by filter0052p3las1.sendgrid.net with SMTP id filter0052p3las1-16097-5CC9D2CF-4 2019-05-01 17:09:35.154799213 +0000 UTC m=+507230.302028899 Received: from herokuapp.com (unknown [54.159.201.37]) by ismtpd0015p1iad1.sendgrid.net (SG) with ESMTP id q9jxZtkoRwi9vHWbp_0_wQ for ; Wed, 01 May 2019 17:09:34.997 +0000 (UTC) Date: Wed, 01 May 2019 17:09:35 +0000 (UTC) From: ruby-core@marc-andre.ca Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 68001 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15815 X-Redmine-Issue-Author: mtsmfm X-Redmine-Sender: marcandre X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-SG-EID: =?us-ascii?Q?jp+swDN4yjawvlS938eDTV7AcuBgTjW2xvQn0nZL4RC8dMjve+G9H02DWPDpP0?= =?us-ascii?Q?9lJKw4Duun84i29hd11UqETueqhs47zpB9a8Nlb?= =?us-ascii?Q?pEv5qxiwygBlGa7ldakNL5paoY9Z51SpBiIJwOO?= =?us-ascii?Q?0m1ObtnEJBA7XJ=2FNEsNiAUL+dkHXEDqnQR+yNF=2F?= =?us-ascii?Q?zCSu4apxCA5nk8CrKIl8FlFjIMv8aEqr+9w=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 92518 Subject: [ruby-core:92518] [Ruby trunk Feature#15815] Add option to raise NoMethodError for OpenStruct X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #15815 has been updated by marcandre (Marc-Andre Lafortune). It's hard to decide on features of `OpenStruct` as it's somewhat an antipattern. Note that you might be able to write `users.map{@[:id]}` in the next version and avoid using an `OpenStruct` altogether. That being said, I am wondering if a frozen `OpenStruct` could possibly raise an error upon reading an undefined key. ---------------------------------------- Feature #15815: Add option to raise NoMethodError for OpenStruct https://bugs.ruby-lang.org/issues/15815#change-77882 * Author: mtsmfm (Fumiaki Matsushima) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- GitHub PR: https://github.com/ruby/ruby/pull/2164 Currently, `OpenStruct#method_missing` returns `nil` even if the key isn't registered. ```ruby require 'ostruct' os = OpenStruct.new({a: 1}) os.a #=> 1 os.b #=> nil ``` I'd like to add `exception` option to raise `NoMethodError` in such case. ```ruby require 'ostruct' os = OpenStruct.new({a: 1}, exception: true) os.a #=> 1 os.b #=> NoMethodError ``` ## Use case I sometimes use OpenStruct as a JSON API response wrapper. It's useful to use method call instead of key access (`obj[:key]`) because we can use `Symbol#to_proc` if it's a method (for example `users.map(&:id)`) But I want to prevent typo for a key name. Currently `users.map(&:idd)` just returns `[nil,...]` Even if we have this `exception` option, we can't enable this option for JSON parser easily though: ```ruby JSON.parse(response, object_class: Class.new(OpenStruct) { def initialize(hash); super(hash, exception: true); end }) ``` What do you think? ---- I've searched with "openstruct nomethoderror" on bugs.ruby-lang.org though, please let me know if it's duplicated. https://bugs.ruby-lang.org/search?utf8=%E2%9C%93&scope=&q=nomethoderror+openstruct -- https://bugs.ruby-lang.org/