Turn Visual and Binding diags on EnableDiagnostics

[StephaneDelcroix]

Description of Change

Turn Visual and Binding diags on EnableDiagnostics

more diagnostics to be plugged on this later

Issues Fixed

• fixes Turn on diagnostics on EnableDiagnostics #29809

[Copilot]

Pull Request Overview

This PR enables Visual and Binding diagnostics by switching the diagnostic flag from DebuggerHelper to a new runtime feature flag. Additionally, it removes the DebuggerHelper dependency and updates tests and build targets accordingly.

• Updated VisualDiagnostics.IsEnabled to use RuntimeFeature.EnableDiagnostics.
• Removed DebuggerHelper and exposed previously internal RuntimeFeature properties as public.
• Updated tests and build targets to use the new diagnostics flag.

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/Core/src/VisualDiagnostics/VisualDiagnostics.cs	Updated IsEnabled condition to rely on RuntimeFeature.EnableDiagnostics rather than debugger status.
src/Core/src/DebuggerHelper.cs	Removed obsolete DebuggerHelper functionality.
src/Core/src/RuntimeFeature.cs	Exposed several runtime feature properties as public and introduced the EnableDiagnostics property.
src/Controls/tests/...	Updated tests to correctly capture and restore the EnableDiagnostics flag state.
src/Controls/src/Core/Xaml/Diagnostics/BindingDiagnostics.cs	Added guard conditions based on RuntimeFeature.EnableDiagnostics.
src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.targets	Added a configuration option for EnableDiagnostics.

Comments suppressed due to low confidence (1)

src/Core/src/RuntimeFeature.cs:31

• Changing these properties from internal to public could represent a breaking change for consumers; please confirm that this change is intentional and properly communicated.

public static bool IsIVisualAssemblyScanningEnabled =>

[StephaneDelcroix]

/cc @jonathanpeppers @simonrozsival

[jonathanpeppers]

There is a doc here, we've been listing each new feature switch:

• https://github.com/dotnet/maui/blob/main/docs/design/FeatureSwitches.md

[spadapet]

I locally copied the NuGet packages from your PR build:

• https://dev.azure.com/xamarin/public/_build/results?buildId=143456&view=artifacts&pathAsName=false&type=publishedArtifacts

And the XAML Binding Failures window doesn't show binding failure anymore.

The repro is:

1. Open the project
2. F5 to build/debug on Windows
3. Edit the {Binding Foo...} just to change Foo to something else that's invalid
4. Look in the XAML Binding Failures window, it should have a new entry for the binding failure

[jonathanpeppers]

$(EnableDiagnostics) is not set by default for Debug mode, so that would be why @spadapet's example didn't work. If you set that in the .csproj, I assume it works?

If we made a new $(EnableMauiDiagnostics) property, maybe its default could be influenced by $(DebuggerSupport), $(Optimize), and $(EnableDiagnostics)?

[spadapet]

$(EnableDiagnostics) is not set by default for Debug mode, so that would be why @spadapet's example didn't work. If you set that in the .csproj, I assume it works?

Yes, once I set <EnableDiagnostics>true</EnableDiagnostics> in the csproj file then binding failures work.

[StephaneDelcroix]

If we made a new $(EnableMauiDiagnostics) property, maybe it's default could be influenced by $(DebuggerSupport), $(Optimize), and $(EnableDiagnostics)?

let's go for added granularity

[PureWeen]

Failing Unit Tests

[StephaneDelcroix]

Failing Unit Tests

should be fixed

[StephaneDelcroix]

failures looks unrelated

[rmarinho]

Just to me consistent some small changes

LGTM

[vitek-karas]

Just curious why we're introducing a new feature switch just for the MAUI part?

Additionally - diagnostics in WASM relates to tracing, profiling and debugger. It's a runtime thing. Here it guards functionality which does logging through DI ILogger and fires events which can be subscribed to by anything in the app.

I understand that semantically these are similar, just want to make sure that we're aware of these differences and it's intentional.

[jonathanpeppers]

Maybe we don't need a second feature switch, but just a second MSBuild property?

$(EnableDiagnostics) adds the Mono diagnostic component in both iOS/Android workloads. But you might want to set $(EnableMauiDiagnostics) in a build without the Mono component but with the extra MAUI diagnostic information.

[StephaneDelcroix]

we went back and forth with one, or 2, flags. I like having a second one for added granularity that defaults to the first one...