Local and Copilot dev can generate public apis

[mattleibow]

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Description of Change

Currently, the only way is to use the IDE and the lightbulb - or manually. This is often not successful and AI still struggles as well.

The new version of the Mono.ApiTools.MSBuildTasks package now has the ability to generate the files and they can be checked in during development to show the actual API changes.

Currently, local dev is not generating automatically because we need to see if this works for everyone. Copilot can help us test, and enabling is just a matter of uncommenting the one line.

The rules would be if this is release of CI, then it is set to Validate only, and then only if it is debug AND not CI (ie: local) will it enable generation.

Issues Fixed

The pain of trying to get IDEs to actually generate files in a multi-targeted world.

[Copilot]

Pull Request Overview

This PR enables automatic generation of public API files locally and via Copilot by integrating the updated Mono.ApiTools.MSBuildTasks package, adding conditional logic in the PublicAPI build targets, and recording new API changes.

• Remove hard-coded version for Mono.ApiTools.MSBuildTasks and centralize versioning
• Introduce PublicApiType conditions and a _GeneratePublicApiFiles target in PublicAPI.targets
• Update PublicAPI.Unshipped.txt across TFMs for new API signatures and hide fields

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/SingleProject/Resizetizer/src/Resizetizer.csproj	Drop explicit Version="0.3.0" to use central version management
src/PublicAPI.targets	Add PublicApiType conditions, conditional analyzer/tasks package refs, and new generate target
src/Controls/src/Core/PublicAPI/*/PublicAPI.Unshipped.txt	Record hiding of Element.transientNamescope and updated FlexLayout.CrossPlatformMeasure
src/Controls/src/Core/Layout/FlexLayout.cs	Remove pragma warnings around the public CrossPlatformMeasure override
src/Controls/src/Core/Element/Element.cs	Remove pragma warnings around the public transientNamescope field
eng/Versions.props	Bump MonoApiToolsMSBuildTasksPackageVersion to 0.4.0
eng/NuGetVersions.targets	Add Mono.ApiTools.MSBuildTasks central package reference

Comments suppressed due to low confidence (4)

src/PublicAPI.targets:40

• Add automated tests (unit or integration) covering the new _GeneratePublicApiFiles target to verify that API files are generated correctly under the Generate condition.

  <Target Name="_GeneratePublicApiFiles" AfterTargets="Build" Condition="'$(TargetFramework)' != '' and '$(PublicApiType)' == 'Generate'">

src/Controls/src/Core/Layout/FlexLayout.cs:467

• The RS0016 suppression pragmas around this public override were removed. This can lead to public API analyzer warnings. Reintroduce #pragma warning disable RS0016 before and #pragma warning restore RS0016 after the method to limit the suppression scope.

		new public Graphics.Size CrossPlatformMeasure(double widthConstraint, double heightConstraint)

src/Controls/src/Core/Element/Element.cs:507

• The pragma disable/restore for RS0016 was removed around this field, causing potential analyzer failures. Add back #pragma warning disable RS0016 above and #pragma warning restore RS0016 below this declaration.

		public INameScope transientNamescope;

src/SingleProject/Resizetizer/src/Resizetizer.csproj:36

• Removing the explicit version relies on central version management. Verify that eng/Versions.props defines the correct version to avoid mismatched package versions in local vs CI builds.

    <PackageReference Include="Mono.ApiTools.MSBuildTasks" PrivateAssets="all" />

[Copilot]

[nitpick] The conditional logic for PublicApiType is fairly complex. Consider adding descriptive comments for each condition or refactoring into smaller, named targets for better readability and future maintenance.

Suggested change

	<!-- The Copilot SWE always generates instead of trying to fix -->
	<PublicApiType Condition="'$(PublicApiType)' == '' and '$(GITHUB_WORKFLOW)' == 'Copilot'">Generate</PublicApiType>
	<!-- The normal CI workflows or Release with NEVER generate, only validate -->
	<PublicApiType Condition="'$(PublicApiType)' == '' and ('$(Configuration)' != 'Debug' or '$(CI)' == 'true' or '$(TF_BUILD)' == 'true')">Validate</PublicApiType>
	<!-- WHEN WE ARE READY: Local Debug workflows will generate -->
	<!-- <PublicApiType Condition="'$(PublicApiType)' == '' and '$(Configuration)' == 'Debug'">Generate</PublicApiType> -->
	<!-- Fall back to validate -->
	<PublicApiType Condition="'$(PublicApiType)' == ''">Validate</PublicApiType>
	</PropertyGroup>
	<!-- Set PublicApiType for Copilot workflows -->
	<PublicApiType Condition="'$(PublicApiType)' == '' and '$(GITHUB_WORKFLOW)' == 'Copilot'">Generate</PublicApiType>
	</PropertyGroup>
	<Target Name="_SetPublicApiTypeForCopilot" Condition="'$(PublicApiType)' == '' and '$(GITHUB_WORKFLOW)' == 'Copilot'">
	<PropertyGroup>
	<PublicApiType>Generate</PublicApiType>
	</PropertyGroup>
	</Target>
	<Target Name="_SetPublicApiTypeForCI" Condition="'$(PublicApiType)' == '' and ('$(Configuration)' != 'Debug' or '$(CI)' == 'true' or '$(TF_BUILD)' == 'true')">
	<PropertyGroup>
	<PublicApiType>Validate</PublicApiType>
	</PropertyGroup>
	</Target>
	<Target Name="_SetDefaultPublicApiType" Condition="'$(PublicApiType)' == ''">
	<PropertyGroup>
	<PublicApiType>Validate</PublicApiType>
	</PropertyGroup>
	</Target>

[jonathanpeppers]

Can you add Inputs/Outputs, so it doesn't run on every incremental build for every project?

Is this right?

Inputs="$(TargetDir)$(AssemblyName).dll"
Outputs="@(PublicAPIFiles)"