Test_BuildAcceleration_ConfigChange

Context

Visual Studio 2022 v17.5 (Feb 2023) added a new feature called "Build Acceleration" that improves incremental build performance: https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes

Build Acceleration directs Visual Studio to only build projects that had modifications while skipping projects that were unchanged. https://github.com/dotnet/project-system/blob/main/docs/build-acceleration.md

However, it does not always pick up changes to settings files that have Build Action set to None or Content when running in debug F5 mode. Previously VS would run MSBuild, which would update changed files and run a build. Now VS handles the file changes itself, and only calls MSBuild when needed. The result is that edits on a settings file don't get picked up, unless you also edit a code file, or explicitly build (Ctrl+B or Ctrl+Shift+B) before running debug.

Testing

1. Open the project in VS 2022, v17.5.X
2. Go to Tools > Options > Projects and Solutions > SDK-Style Projects: tick Don't call MSBuild if a project appears to be up to date.
3. Run the project. The config values in appsettings.json should be output to the console window
4. Change the Build Action property of the appsettings.json file to something like None, Content, Resource or Embedded Resource
5. Build and run the application
6. Edit a config setting and run in debug F5 (don't force a rebuild). Check if the config change is picked up and displayed to the console.

Findings

• Build Action: None - changes not picked up
• Build Action: Content - changes not picked up
• Build Action: Resource - throws a runtime error
• Build Action: Embedded Resource - changes are picked up