Slide 1
Slide 1 text
Introduction of new
features for VS Code
debugging
Naoto ONO
Slide 2
Slide 2 text
Naoto ONO
• Developer Productivity Group at CyberAgent, Inc
• ruby/debug (debug.gem), ruby/vscode-rdbg contributor
• Chrome Integration
• E2E Test Frameworks
• GitHub: @ono-max
Slide 3
Slide 3 text
Question: have you ever read
code with a debugger?
Slide 4
Slide 4 text
Code reading with a debugger is
great!
Slide 5
Slide 5 text
Code reading with a debugger is
great! However, ...
Slide 6
Slide 6 text
Reading complex code is still
hard, isn’t it?
Slide 7
Slide 7 text
Demo: Read complex code
with debug.gem.
Slide 8
Slide 8 text
No content
Slide 9
Slide 9 text
Read code inside of
Active Record object
Slide 10
Slide 10 text
No content
Slide 11
Slide 11 text
Dif
fi
culty of Reading complex code
• We sometimes forget which method was called when we stopped before
😭
• We sometimes forget to take note of the return value of the methods 😖
Slide 12
Slide 12 text
What should we do?
Slide 13
Slide 13 text
What should we do?
=> Let’s trace the program with
Trace Inspector!!
Slide 14
Slide 14 text
Agenda
• Main topic: Trace Inspector
• Subtopic: VS Code Debug Visualizer
Slide 15
Slide 15 text
Trace Inspector
Slide 16
Slide 16 text
Demo: Trace the program with
Trace Inspector
Slide 17
Slide 17 text
No content
Slide 18
Slide 18 text
Trace “bar” method
Slide 19
Slide 19 text
No content
Slide 20
Slide 20 text
(Repeat) Dif
fi
culties in reading complex codes.
• We sometimes forget which method was called when we stopped before
😭
• We sometimes forget to take note of the return value of the methods 😖
Slide 21
Slide 21 text
(Repeat) Dif
fi
culties in reading complex code.
• We sometimes forget which method was called when we stopped before
😭
• We sometimes forget to take note of the return value of the methods 😖
=> We can solve the above problems in Trace Inspector!!
Slide 22
Slide 22 text
Trace Inspector
• We can check which method was called anytime 😁
• We can copy parameters and return value by clicking the target log 😃
• All organized tracing logs help you to understand the procedure 🤗
Slide 23
Slide 23 text
Summary of Demo
• How to start Trace Inspector
1. Click “Enable Trace”
2. Execute the program
• If you click a log, the target
fi
le is opened, and the line is highlighted.
• Parameters and return values are displayed in the editor.
Slide 24
Slide 24 text
We want to record local variables
and backtraces, don’t we?
Slide 25
Slide 25 text
Record And Replay
• We can record local variables and backtraces by enabling “Record And
Replay” mode.
• “Record And Replay” mode is disabled in the default since it’s slow.
Slide 26
Slide 26 text
Demo: Trace local variables and
backtraces with Trace Inspector
Slide 27
Slide 27 text
No content
Slide 28
Slide 28 text
Trace “bar” method
Slide 29
Slide 29 text
No content
Slide 30
Slide 30 text
Summary of Demo
• How to record local variables and backtraces
1. Click “•••” (more icon), then put a checkmark of “Record And Replay
(Slow)”
2. Click “Enable Trace”
3. Execute the program
•
Slide 31
Slide 31 text
Options for tracing
Location
Method name &
Params
Return Value Backtrace Local variables
Trace Line
(Default)
✅ N/A N/A
Trace Call/Return
(Default)
✅ ✅ ✅
Record And
Replay
✅ ✅ ✅ ✅ ✅
Slide 32
Slide 32 text
Performance Comparison for each option
Execution Time (sec)
Without tracing (Normal mode) 0.007
Trace Line 0.063
Trace Call/Return 0.437
Record And Replay 10.640
x 9.0
x 62.4
x 1520.0
ruby 3.2.1 (2023-02-08 revision 31819e82c8) [arm64-darwin21]
MacBook Pro (16-inch, 2021)
Chip: Apple M1 Max
Memory 32 GB
Slide 33
Slide 33 text
Comparison with existing tracing tools
Overview Frontend
Trace Inspector
A tool that improves the UI
of rdbg (CLI)
VS Code
rdbg (CLI)
A tool that traces
debugging programs
Terminal
ruby/tracer
A tool that traces executing
programs
Terminal
Slide 34
Slide 34 text
Comparison with existing tracing tools
Overview Frontend
Trace Inspector
A tool that improves the UI
of rdbg (CLI)
VS Code
rdbg (CLI)
A tool that traces
debugging programs
Terminal
ruby/tracer
A tool that traces executing
programs
Terminal
Trace Inspector can provide
rich user experiences
by making use of VS Code!!
Slide 35
Slide 35 text
The way of displaying trace logs
rdbg(CLI) Trace Inspector
Slide 36
Slide 36 text
The way of displaying trace logs
rdbg(CLI) Trace Inspector
You can see only what you
want to see by clicking!
A trace log
Slide 37
Slide 37 text
The way of displaying trace logs
rdbg(CLI) Trace Inspector
You can see only what you
want to see by clicking!
Slide 38
Slide 38 text
Trace logs can be viewed on the editor
The line is highlighted!
Slide 39
Slide 39 text
Trace logs can be viewed on the editor
Parameters are displayed on
the editor!
Slide 40
Slide 40 text
The history to develop Trace Inspector
Start developing the tracing
tool that improves the UI of
rdbg (CLI).
History Inspector is
introduced in RubyKaigi
2022.
Trace Inspector which
improves History Inspector,
is introduced now!
Slide 41
Slide 41 text
How does Trace Inspector
work?
Slide 42
Slide 42 text
How does Trace Inspector work?
VS Code debug.gem
VS Code extension
Slide 43
Slide 43 text
How does Trace Inspector work?
VS Code debug.gem
VS Code extension
Slide 44
Slide 44 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
JSON
Slide 45
Slide 45 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Slide 46
Slide 46 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Slide 47
Slide 47 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Click “Enable Trace”
Slide 48
Slide 48 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Click “Enable Trace”
Enable Trace
Slide 49
Slide 49 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Click “Enable Trace”
Enable Trace
Success
Slide 50
Slide 50 text
Debug Adapter Protocol (DAP)
VS Code extension debug.gem
Change “Enable Trace” to
“Disable Trace”
Enable Trace
Success
Slide 51
Slide 51 text
Conclusion of Trace Inspector
• Trace Inspector is available in debug.gem version 1.8.
• Trace Inspector helps you to read complex code.
Slide 52
Slide 52 text
VS Code Debug Visualizer
Slide 53
Slide 53 text
Demo: Visualize objects in VS
Code Debug Visualizer
Slide 54
Slide 54 text
No content
Slide 55
Slide 55 text
Visualize variable “foo"
Slide 56
Slide 56 text
No content
Slide 57
Slide 57 text
VS Code Debug Visualizer
• A VS Code extension that visualizes objects while debugging.
• This extension is created by Henning Dieterichs (@hediet).
Slide 58
Slide 58 text
Supported Languages (Excerpt)
• JavaScript
• Python
• Go
• C++
• Java
•
Slide 59
Slide 59 text
• JavaScript
• Python
• Go
• C++
• Java
• Ruby <- New!!
Supported Languages (Excerpt)
Slide 60
Slide 60 text
How Ruby objects are
visualized?
Slide 61
Slide 61 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
debugvisualizer.gem
Slide 62
Slide 62 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
debugvisualizer.gem
What I developed this time!
Slide 63
Slide 63 text
How Ruby object are visualized?
VS Code Debug
Visualizer
Slide 64
Slide 64 text
How Ruby object are visualized?
VS Code Debug
Visualizer
Enter “foo”
Slide 65
Slide 65 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
Evaluate “foo”
Enter “foo”
Slide 66
Slide 66 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
Evaluate “foo”
debugvisualizer.gem
Result
Slide 67
Slide 67 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
debugvisualizer.gem
Result
VS Code Debug
Visualizer Protocol
Evaluate “foo”
Slide 68
Slide 68 text
How Ruby object are visualized?
VS Code Debug
Visualizer debug.gem
debugvisualizer.gem
Result
Evaluate “foo”
VS Code Debug
Visualizer Protocol
Slide 69
Slide 69 text
Inside story of using VS Code Debug Visualizer
• Although we planned to create the front end by ourselves at
fi
rst, we had
the following problems:
• Maintenance cost
• Risk of using third-party libraries
• We decided to use VS Code Debug Visualizer to solve the above issues.
Slide 70
Slide 70 text
Conclusion
Slide 71
Slide 71 text
New features for VS Code debugging
• Trace Inspector
• Please update your version of debug.gem to the latest version!
• VS Code Debug Visualizer
Slide 72
Slide 72 text
Helpful references to review my talk
• Trace Inspector
• https://github.com/ruby/debug/pull/959
• VS Code Debug Visualizer
• https://github.com/hediet/vscode-debug-visualizer
• https://github.com/ono-max/debugvisualizer
• (Japanese) https://zenn.dev/ono_max/articles/cb5cf14caef2d8
Slide 73
Slide 73 text
Acknowledgement
• Koichi Sasada san (@ko1)
• He helped me to design Trace Inspector.
• If it had not been for his help, I wouldn’t have been here!
• Thank you for giving me much feedback about Trace Inspector!
• Yusuke Endoh san (@mame)
• Mari Imaizumi san (@ima1zumi)
• Yuki Torii san (@yotii23)
Slide 74
Slide 74 text
Thank you for your time!