As seen on the 2-part Channel9 videos on the Visual Studio Toolbox show with Robert Green.

1. Writing High Quality Visual Studio Extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

2. 2
@omerraviv on Twitter (twitter picture)
@omerraviv on Gitter.im/extendvs (Gitter logo)
Omer Raviv
• Creator and CTO of OzCode
• Senior Consultant @ CodeValue
• .NET open-source enthusiast
• Passionate about dev productivity
@omerraviv on Twitter
@omerraviv on Gitter (gitter.im/extendvs)

3. My Journey as a developer

4. Every minute
spent in the debugger
is a minute squandered

5. The two most common ways to use a debugger:
1. Wasting time
2. Quality time

6. Wasting time:
Not knowing what your hypothesis is at any given time
Getting into a rot mindlessly hitting F10
Quality time:
Apply the Scientific Method, religiously
Simplify the scenario, then write a test!
The Debugging Process Overview
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

7. Why can’t
Johnny do Test
Driven
Development?

8. A typical unit test
Test Driven Woes

9. 2 Unit Tests. 0 Integration Tests.

11. UI
System/
Subcutaneous
Unit
Automation
Harder
Easier
Exploration
Mike Cohn’s Test
Automation Pyramid
Writing test at the right level of granularity

12. UI
System/
Subcutaneous
Unit
Exploration
Writing test at the right level of granularity
Microsoft/VisualStudio-TestHost/TestUtilities , PTVS
JaredPar/VsVim/Test
OzCode/VSIntegrationTestSamples

13. • Synthesis and refinement of practices stemming from TDD & ATDD
• User story:
"As a [role] I want [feature] so that [benefit]”
• Acceptance Criteria
Given [initial context]
When [event occurs]
Then [ensure some outcome]
What’s this BDD thing?

14. Create living, executable
Specification.
New feature?
Can I see the
requirements doc
please?
What’s BDD all about?

15. • Use natural language to express intentions (Given…When…Then)
• Use a general purpose programming language
to express test mechanics
• Use a tool that will let you operate in either domain seamlessly
BDD offers a solution

16. Michael WhelanMehdi Khalili Jake Ginnivan Jason Roberts
PM> Install-Package TestStack.BDDfy

17. • Works with any testing framework
• Does not require its own test runner
• Creates Humanized, story-like error messages
A few quick BDDfy facts:

18. Demo time!

20. My very first Visual Studio
Subcutaneous Test

21. Having flakey tests is a lot worse than having no tests at all.
A flakey test is like a virus –
quarantine it, then triage.
Visual Studio Integration Tests Pro-Tip

22. Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

23. The ActivityLog.xml
MessageBox
…of pain and suffering

24. The ActivityLog.xml
MessageBox
…of pain and suffering github.com/oz-code/OzCode.VisualStudioExtensionAnalyzers
PM> Install-Package OzCode.VisualStudioExtensionAnalyzers

25. Use an Exception Monitoring Tool
Use an Exception Monitoring Tool

26. Use an Exception Monitoring Tool

27. Dealing with crashes
Starting with VS2017.3, users get a notification if an exception might be involved in a crash.

28. https://gist.github.com/oz-code/76446034c493685bfaabdd5aecc43180
Dealing with crashes

29. Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

30. Visual Studio 2017 will warn users about extensions that are slowing things down.
Performance as a Feature

31. 1. Delay loading your extension as much as possible (using UIContextRule)
2. When you do load, load in the background. (using AsyncPackage)
Performance as a Feature

32. OzCode F10 Monkey
http://www.github.com/oz-code/VSExplorationTests

33. Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

34. Memory Leaks vs. GC Pressure
GC Pressure:
Memory Leak:

35. Memory Leaks vs. GC Pressure
Pro-Tip: Don’t Close your Diagnostics Tools Window!

36. Dealing with GC Pressure
Memory Leaks vs. GC Pressure
• Always be measuring (allocations, % time spent in GC)
• Watch out for duplicate strings
• Use object pooling / a string intern pool
• Use Roslyn Heap Allocation Analyzer

37. github.com/jaredpar/vsvim
Memory Leak Testing
Subcutaneous Tests Pro-Tip

38. Memory Leak Testing
Subcutaneous Tests Pro-Tip

39. Which means…
…a business sponsor could request that the current
development version of the software can be deployed
into production at a moment's notice - and nobody
would bat an eyelid, let alone panic.
Got good Subcutaneous Tests?
Start practicing True Continuous Delivery!
Martin Fowler

40. Thank You!
@oz_code
http://oz-code.com