Use of (dynamic) causes AOT compilation to fail

[SteveBush]

Using dynamic in .NET MAUI can lead to issues with Ahead-of-Time (AOT) compilation, especially on platforms like iOS that do not support dynamic code generation using System.Reflection.Emit. This can result in errors such as PlatformNotSupported_ReflectionEmit.

Dark casts to (dynamic) in building the query pipeline. IOS and other Ahead of Time compiled executables don't support System. Reflection.Emit as they don't support compiling code at runtime for security reasons.

The request is to remove the casting to (dynamic) in the pipeline generation code. It's used to cast between IQueryHandler and Fallback generic types.

[SteveBush]

I'm going to attempt to remove the use of dynamic from Darker and support AOT compilation. Here's my plan:

• Create a new test project Paramore.Darker.Tests.AOT that targets net8.0 and net9.0 and defines true. This will force the test project to compile with AOT. AOT is only supported on net7.0+.
• Write tests that fail when dynamic is used. MOQ is incompatible with AOT as it uses System.Reflection.Emit.
• Rewrite the query pipeline to handle casting to generic types without using dynamic
• Validate all of the tests pass
• Create a pull request with the changes.

I'm still working out the required changes to the query pipeline. I will update this issue with my proposed changes.

[SteveBush]

I spent a couple of hours on this issue this morning. I added a test project, some test helpers, and a MAUI test application to the dev-removedynamic branch. I have been able to reproduce the bug in the MAUI test application. The AOT compiler is only used in Release build configurations. The unfortunate side effects are that release builds take forever, there is no debugging information, and you cannot use a debugger, as all of these features are stripped out in the AOT compilation process.

My next step is remove all usages of (dynamic) casting and verify all tests still pass. Then I will verify the revised code works in the MAUI application.

[iancooper]

I should have fixed the build issues on this. If it builds, I can get a release out

[SteveBush]

@iancooper What's the timing for pushing out release 4.10 to NuGet?

[iancooper]

@SteveBush Sorry, I need to fix some build issues. I made life hard by switching to build the test project, and not the others. Hoping to do it this weekend. Got a little sandbagged at work

[iancooper]

Possible @holytshirt can fix, if not, once I am back from Australia is most likely.
@holytshirt we need to avoid building the sln file because we don't want to build the Maui sample on our GHA server. I fixed that by only building tests, for CI, but CD I need to build all the core packages.

[SteveBush]

@iancooper. I suggest that we completely remove the MAUI sample to make building in CI easier. It served its purpose and you can direct anyone to me about how to build in Brighter or Darker using MAUI.

Another workaround is to just manually publish the built packages on GitHub to Nuget.

[iancooper]

@iancooper. I suggest that we completely remove the MAUI sample to make building in CI easier. It served its purpose and you can direct anyone to me about how to build in Brighter or Darker using MAUI.

Another workaround is to just manually publish the built packages on GitHub to Nuget.

We could move it into a separate samples repo. That way it is there, but doesn't make the build harder

[holytshirt]

All sorted, I've created a filtered solution you can open either the solution or filtered solution.

I'm also building using the filtered solution