Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
HOW TO READ HUGE OPEN SOURCE CODE EASILY
Search
Sponsored
·
Ship Features Fearlessly
Turn features on and off without deploys. Used by thousands of Ruby developers.
→
yhirano55
May 01, 2019
Technology
870
3
Share
HOW TO READ HUGE OPEN SOURCE CODE EASILY
for RailsConf 2019 LT
yhirano55
May 01, 2019
More Decks by yhirano55
See All by yhirano55
カンファレンス型 技術イベントの作り方 〜Rails Developers Meetup の辿った道〜 / How to Organize a Tech Conference
yhirano55
27
6.7k
Other Decks in Technology
See All in Technology
Dynamic Workersについて
yusukebe
2
530
類似画像検索モデルの開発ノウハウ
lycorptech_jp
PRO
4
1.1k
Javaで学ぶSOLID原則
negima
1
240
Databricks 月刊サービスアップデート 2026年05月号
tyosi1212
0
120
管理アカウント単一運用からAWS Organizationsに移行するの大変で滅
hiramax
0
360
自称宇宙最速で不合格となったAIP-C01にリベンジを果たすべくAIで問題集アプリを作ってみた。
yama3133
0
250
Oracle AI Database@Azure:サービス概要のご紹介
oracle4engineer
PRO
6
1.8k
Kaggle未経験社員をメダリストに育てる「AIドラゴン桜」
lycorptech_jp
PRO
0
690
20260528_生成AIを専属DSに_Howの次にすべきことを考える
doradora09
PRO
0
270
string地獄を脱出する
sansantech
PRO
1
110
Strands Agents超入門
kintotechdev
1
150
電子辞書Brainをネットに繋げてみた(自力編)
raspython3
0
390
Featured
See All Featured
Testing 201, or: Great Expectations
jmmastey
46
8.2k
Producing Creativity
orderedlist
PRO
348
40k
SEO in 2025: How to Prepare for the Future of Search
ipullrank
3
3.5k
WCS-LA-2024
lcolladotor
0
610
How People are Using Generative and Agentic AI to Supercharge Their Products, Projects, Services and Value Streams Today
helenjbeal
1
200
A Guide to Academic Writing Using Generative AI - A Workshop
ks91
PRO
1
310
We Have a Design System, Now What?
morganepeng
55
8.2k
Lightning talk: Run Django tests with GitHub Actions
sabderemane
0
190
[SF Ruby Conf 2025] Rails X
palkan
2
1.1k
Building Experiences: Design Systems, User Experience, and Full Site Editing
marktimemedia
0
520
Typedesign – Prime Four
hannesfritz
42
3.1k
Optimizing for Happiness
mojombo
378
71k
Transcript
HOW TO READ HUGE OPEN SOURCE CODE EASILY @yhirano55 at
RailsConf 2019
self.inspect ➤Yoshiyuki Hirano from JAPAN ➤GitHub: @yhirano55 ➤Twitter: @yoshi_hirano ➤Rails
Contributors #62 ➤I’m chief organizer of “Railsdm” ➤I love Rails community
Have you ever read Ruby on Rails source code?
MORE QUESTIONS ➤Do you know the request/response Lifecycle of Rails
application? ➤Do you know the steps of Active Record's create, update, validate, and destroy? ➤Do you know the processing of initialization of Rails application?
I do not think many of them actually do
To tell the truth,
I have not, too
I guess we don't have much time and patience
Yesterday, I was impressed by Skylight’s sponsor talk. The design
of the rack application is really elegant
AND.. ➤I want to read the code of its lifecycle
of Rails application ➤But I don't want to spend much time to trace the code ➤I want to read source code easily. What would you do?
Finally, I've shipped a new RubyGem this morning
yhirano55/trace_location
DEMO
At first, boot rails console, and set request env
And execute `Rails.application.call(env)` inside `TraceLocation.trace` block
Then it generates a log file
It’s traced locations about `Rails.application.call(env)`
It’s traced locations about `Rails.application.call(env)` CALL on rails/engine.rb:522 #call
It’s traced locations about `Rails.application.call(env)` CALL on rails/application.rb:607 #build_request
It helps you can get tracing the processing of the
Lifecycle of Rails application easily!!
HOW IT WORK? ➤Use TracePoint that is a Ruby standard
API ➤TracePoint API is one of the BLACK MAGIC in Ruby
IMPLEMENTATION This is TracePoint
IMPLEMENTATION Collect logs
IMPLEMENTATION Trace events while block call And disable when it
finished
In making this gem, I used TracePoint for the first
time. It makes me really feel so good!!
It helps you get deeply understanding Ruby on Rails
It's my pleasure to help you enjoy Ruby on Rails
self.inspect ➤Yoshiyuki Hirano from JAPAN ➤GitHub: @yhirano55 ➤Twitter: @yoshi_hirano ➤Rails
Contributors #62 ➤I’m chief organizer of “Railsdm” ➤I love Rails community
We’re going to have a new Ruby on Rails conference
The name is…
RailsKaigi 2020
We hope you join RailsKaigi 2020 in Japan
yhirano55/trace_location Thank you so much