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.

10.
UI
System/
Subcutaneous
Unit
Automation
Harder
Easier
Exploration
Mike Cohn’s Test
Automation Pyramid
Writing test at the right level of granularity

11.
UI
System/
Subcutaneous
Unit
Exploration
Writing test at the right level of granularity
Microsoft/VisualStudio-TestHost/TestUtilities , PTVS
JaredPar/VsVim/Test
OzCode/VSIntegrationTestSamples

12.
• 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?

13.
Create living, executable
Specification.
New feature?
Can I see the
requirements doc
please?
What’s BDD all about?

14.
• 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

15.
Michael WhelanMehdi Khalili Jake Ginnivan Jason Roberts
PM> Install-Package TestStack.BDDfy

16.
• Works with any testing framework
• Does not require its own test runner
• Creates Humanized, story-like error messages
A few quick BDDfy facts:

17.
Demo time!

18.
My very first Visual Studio
Subcutaneous Test

19.
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

20.
Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

21.
The ActivityLog.xml
MessageBox
…of pain and suffering

22.
The ActivityLog.xml
MessageBox
…of pain and suffering github.com/oz-code/OzCode.VisualStudioExtensionAnalyzers
PM> Install-Package OzCode.VisualStudioExtensionAnalyzers

23.
Use an Exception Monitoring Tool
Use an Exception Monitoring Tool

24.
Use an Exception Monitoring Tool

25.
Dealing with crashes
Starting with VS2017.3, users get a notification if an exception might be involved in a crash.

26.
https://gist.github.com/oz-code/76446034c493685bfaabdd5aecc43180
Dealing with crashes

27.
Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

28.
Visual Studio 2017 will warn users about extensions that are slowing things down.
Performance as a Feature

29.
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

30.
OzCode F10 Monkey
http://www.github.com/oz-code/VSExplorationTests

31.
Writing High Quality Visual Studio extensions
Omer Raviv | omerr@codevalue.net | @omerraviv
www.oz-code.com | @oz_code
Testable, stable, performant, memory efficient

32.
Memory Leaks vs. GC Pressure
GC Pressure:
Memory Leak:

33.
Memory Leaks vs. GC Pressure
Pro-Tip: Don’t Close your Diagnostics Tools Window!

34.
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

35.
github.com/jaredpar/vsvim
Memory Leak Testing
Subcutaneous Tests Pro-Tip

36.
Memory Leak Testing
Subcutaneous Tests Pro-Tip

37.
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

38.
Thank You!
@oz_code
http://oz-code.com