On .NET Live: Lessons Learned Building Source Generators

C# code generators are tools that automatically create source code based on predefined templates or rules. In this week's episode, community MVP Jason Bock returns to show us lessons he's learned about what works, what doesn't, and what developers should avoid!
⌚ Chapters:
00:00 Countdown begins
03:12 Welcome to On .NET Live
03:57 Jason Bock intro
06:48 Source Generators - overview
11:12 Demo - lessons learned
57:00 In summary
59:21 Wrap
Resources:
Blog:
devblogs.microsoft.com/dotnet...
Source Generators Docs:
learn.microsoft.com/en-us/dot...
Jason's Repo: github.com/JasonBock/Rocks
Benchmark Mock Net Repo:
github.com/ecoAPM/BenchmarkMo...
Incremental Generators Repo:
github.com/dotnet/roslyn/blob...
Null Safety Docs:
learn.microsoft.com/en-us/tra...
Featuring: Jason Bock, Frank Boucher, David Pine (@davidpine7), Cam Soper
#code-generators

[@NotInventedHereShow]

Excellent walkthrough. A few suggestions:
You don't need to restart VS to observe changes to a source generator in another project. A `dotnet build-server shutdown` at the command line resets the build-server cache and forces the generators to re-run from scratch.
Wrt. to nullable, I typically wrap generated code in `#nullable annotation`/`#nullable restore`. Then I do not have to use the damn-it operator in the generated code.

[@daniloa.1455]

20:28 Target .NET Standard 2.0
22:37 Use IIncrementalGenerator
23:44 ForAttributeWithMetadataName()
27:37 Use Immutable, Read-Only Models
???? Code Generation
32:14 Naming Collisions
37:25 Avoid Package References
39:18 Be Nullable, but Be Forgiving
42:16 Reloading Sucks
46:47 Roslyn APIs can be "Surprising"

[@VOXindie]

Start at 5:30

[@IgnatAndrei]

You can modify source code with Roslyn Code Generator that writes interceptors.

[@JasonBock]

....sort of. You can intercept method invocations, but you can't change method bodies. Also, AFAIK, interceptors are still an experimental feature, so I didn't want to get into that in the talk - I had to enough to cover as-is :)

[@StephenJWalter]

Starts at about 3:56

[@ilayarajag6064]

hi