Ruby ecosystem development introduction workshop: Tokyo: 2026-08-05: sngsmz: factory_bot: Work log

[sngsmz]

This is a work log of a "Ruby ecosystem development introduction workshop".
"Ruby ecosystem development introduction workshop" is an activity to increase Ruby ecosystem developers.
Here's been discussed in Japanese. Thanks.

作業ログ作成時の説明

以下のテンプレートを埋めてタイトルに設定します。埋め方例はスクロールすると見えてきます。

Ruby ecosystem development introduction workshop: Tokyo: #{YEAR}-#{MONTH}-#{DAY}: #{ACCOUNT_NAME}: #{PRODUCT_NAME}: Work log

タイトル例↓：

Ruby ecosystem development introduction workshop: Tokyo: 2026-08-05: kou: Rabbit: Work log

Rubyエコシステム開発入門ワークショップ関連情報

• スライド：ワークショップの進行に使っているスライドがあります。
• ruby-jp Slackの#oss_gateチャンネル：Rubyエコシステムの開発に関することならなんでも相談できます。ワークショップが終わった後もオンラインで相談しながら継続的にRubyエコシステムの開発に参加しましょう！
• 過去のビギナーの作業ログ：他の人の作業ログから学べることがいろいろあるはずです。

[sngsmz]

MIT ライセンスだった
以下で OSS であることを確認
https://opensource.org/licenses/

readme を読んでみる
https://github.com/thoughtbot/factory_bot

[sngsmz]

コードをローカルに落とす

git clone https://github.com/thoughtbot/factory_bot.git

[sngsmz]

bundle で入れてみる

$ bundle add factory_bot
Fetching gem metadata from https://rubygems.org/.........
Fetching prism 1.5.2
Fetching aruba 2.3.2
Installing aruba 2.3.2
Installing prism 1.5.2 with native extensions

[sngsmz]

マニュアルで入れられるか確認する

$ gem install factory_bot
Fetching factory_bot-6.6.0.gem
Successfully installed factory_bot-6.6.0
Parsing documentation for factory_bot-6.6.0
Installing ri documentation for factory_bot-6.6.0
Done installing documentation for factory_bot after 0 seconds
1 gem installed

A new release of RubyGems is available: 4.0.10 → 4.0.18!
Run `gem update --system 4.0.18` to update your installation.

[sngsmz]

readme をみてもセットアップの方法がいまいちわからない
ちゃんと確認するなら rails アプリが必要？

bin/setup とbin/consoleが開発者向けに用意されてるのが判明

$ bin/setup 

bundle install
+ bundle install
Bundle complete! 14 Gemfile dependencies, 72 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

$ bin/console
bin/console:12: warning: irb used to be loaded from the standard library, but is not part of the default gems since Ruby 4.0.0.
You can add irb to your Gemfile or gemspec to fix this error.
/Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/4.0.0/bundled_gems.rb:60:in 'Kernel.require': cannot load such file -- irb (LoadError)
Did you mean?  erb
        from /Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/4.0.0/bundled_gems.rb:60:in 'block (2 levels) in Kernel#replace_require'
        from bin/console:12:in '<main>'

factory_bot.gemspecに以下を追加した

s.add_development_dependency("irb")

動いた

$ bin/console
irb(main):001> 

[sngsmz]

build を動かす

irb(main):001* class User
irb(main):002*   attr_accessor :name, :email
irb(main):003*   def initialize(attrs = {})
irb(main):004*     attrs.each { |k, v| public_send("#{k}=", v) }
irb(main):005*   end
irb(main):006> end
irb(main):007* FactoryBot.define do
irb(main):008*   factory :user do
irb(main):009*     name { "Jane" }
irb(main):010*     email { "jane@example.com" }
irb(main):011*   end
irb(main):012> end
irb(main):013> FactoryBot.build(:user)
=> #<User:0x0000000122a404c0 @email="jane@example.com", @name="Jane">

[sngsmz]

実際に DB を使って試せるスクリプトを動かす

$ ruby .github/REPRODUCTION_SCRIPT.rb
Fetching gem metadata from https://rubygems.org/........
Resolving dependencies...
Fetching concurrent-ruby 1.3.8
Fetching connection_pool 3.0.2
Fetching json 2.21.2
Fetching uri 1.1.1
Fetching timeout 0.6.1
Fetching sqlite3 2.9.5 (arm64-darwin)
Installing connection_pool 3.0.2
Installing concurrent-ruby 1.3.8
Installing json 2.21.2 with native extensions
Installing uri 1.1.1
Fetching i18n 1.15.2
Installing timeout 0.6.1
Installing i18n 1.15.2
Installing sqlite3 2.9.5 (arm64-darwin)
Fetching activesupport 8.1.3.1
Installing activesupport 8.1.3.1
Fetching activemodel 8.1.3.1
Installing activemodel 8.1.3.1
Fetching activerecord 8.1.3.1
Installing activerecord 8.1.3.1
-- create_table(:posts, {force: true})
D, [2026-08-05T12:21:30.641952 #51010] DEBUG -- :    (1.0ms)  DROP TABLE IF EXISTS "posts"
D, [2026-08-05T12:21:30.642136 #51010] DEBUG -- :    (0.1ms)  CREATE TABLE "posts" ("id" integer PRIMARY KEY AUTOINCREMENT NOT NULL, "body" varchar)
   -> 0.0021s
D, [2026-08-05T12:21:30.642462 #51010] DEBUG -- :    (0.0ms)  CREATE TABLE "schema_migrations" ("version" varchar NOT NULL PRIMARY KEY)
D, [2026-08-05T12:21:30.642895 #51010] DEBUG -- :    (0.0ms)  CREATE TABLE "ar_internal_metadata" ("key" varchar NOT NULL PRIMARY KEY, "value" varchar, "created_at" datetime(6) NOT NULL, "updated_at" datetime(6) NOT NULL)
D, [2026-08-05T12:21:30.648421 #51010] DEBUG -- :   ActiveRecord::InternalMetadata Load (0.1ms)  SELECT * FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = ? ORDER BY "ar_internal_metadata"."key" ASC LIMIT 1  [[nil, "environment"]]
D, [2026-08-05T12:21:30.649106 #51010] DEBUG -- :   ActiveRecord::InternalMetadata Create (0.1ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ('environment', 'default_env', '2026-08-05 03:21:30.648449', '2026-08-05 03:21:30.648451') RETURNING "key"
Run options: --seed 46188

# Running:

.

Finished in 0.001619s, 617.6652 runs/s, 617.6652 assertions/s.

1 runs, 1 assertions, 0 failures, 0 errors, 0 skips

[sngsmz]

bin/console のupdate

https://github.com/thoughtbot/factory_bot/blob/967d128e3710b9918f97c75b47b11251e85c2377/NEWS.md?plain=1#L39

[sngsmz]

これを確認
https://github.com/thoughtbot/factory_bot/blob/main/CONTRIBUTING.md

factory_bot.gemspec の修正PRを作るために fork

https://github.com/sngsmz/factory_bot

ブランチを切った

$ git checkout -b add-irb-dev-dependency

[sngsmz]

テスト実行で warning はでてるので、ここもコントリビュートできるかも

$ bundle exec rake
/Users/shingo.shimizu/.rbenv/versions/4.0.5/bin/ruby -I/Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-core-3.13.5/lib:/Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-support-3.13.6/lib /Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-core-3.13.5/exe/rspec --pattern spec/\{\*_spec.rb,factory_bot/\*\*/\*_spec.rb\}

Randomized with seed 40578
.............................................................................................................................................................................................................................................................................................................................................

Deprecation Warnings:

The implicit block expectation syntax is deprecated, you should pass a block rather than an argument to `expect` to use the provided block expectation matcher or the matcher must implement `supports_value_expectations?`. e.g  `expect { value }.to raise FactoryBot::AssociationDefinitionError with "Unexpected block passed to 'author' association in 'user' factory"`not `expect(value).to raise FactoryBot::AssociationDefinitionError with "Unexpected block passed to 'author' association in 'user' factory"`


If you need more of the backtrace for any of these deprecations to
identify where to make the necessary changes, you can configure
`config.raise_errors_for_deprecations!`, and it will turn the
deprecation warnings into errors, giving you the full backtrace.

1 deprecation warning total

Finished in 0.32567 seconds (files took 0.2104 seconds to load)
333 examples, 0 failures

Randomized with seed 40578

Coverage report generated for RSpec to /Users/shingo.shimizu/oss-workspace/factory_bot/coverage.
Line Coverage: 84.24% (1133 / 1345)
/Users/shingo.shimizu/.rbenv/versions/4.0.5/bin/ruby -I/Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-core-3.13.5/lib:/Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-support-3.13.6/lib /Users/shingo.shimizu/.rbenv/versions/4.0.5/lib/ruby/gems/4.0.0/gems/rspec-core-3.13.5/exe/rspec --pattern spec/acceptance/\*\*/\*_spec.rb

Randomized with seed 47958
...............................................................................................................................................................................................................................................................................................................................................................................................................................................

Finished in 4.84 seconds (files took 0.16943 seconds to load)
431 examples, 0 failures

Randomized with seed 47958

Coverage report generated for RSpec to /Users/shingo.shimizu/oss-workspace/factory_bot/coverage.
Line Coverage: 96.58% (1299 / 1345)
/Users/shingo.shimizu/.rbenv/versions/4.0.5/bin/ruby -S bundle exec cucumber --format progress
Using the default profile...
..................

4 scenarios (4 passed)
18 steps (18 passed)
0m0.013s
Coverage report generated for Cucumber Features, RSpec to /Users/shingo.shimizu/oss-workspace/factory_bot/coverage.
Line Coverage: 96.73% (1331 / 1376)
Inspecting 155 files
...........................................................................................................................................................

155 files inspected, no offenses detected

[sngsmz]

最近の PR を見てお作法を確認しておく
thoughtbot/factory_bot#1795

[sngsmz]

PR 作成してみた

• Add irb as a development dependency thoughtbot/factory_bot#1832

[sngsmz]

test の warning の PR も作成した

• Fix RSpec deprecation for raise_error expectation thoughtbot/factory_bot#1833