Align Microsoft.NET.Sdk implicit usings with ASP.NET Core by adding System.Net.Http.Json for net11+

[Copilot]

Console apps using Microsoft.NET.Sdk require an explicit using System.Net.Http.Json; where ASP.NET Core apps do not. This change aligns implicit-using behavior by including System.Net.Http.Json in default C# implicit usings for .NETCoreApp targeting 11.0+.

• SDK implicit usings update

  • Updated src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.CSharp.props to include:
    • System.Net.Http.Json when:
      • $(TargetFrameworkIdentifier) == '.NETCoreApp'
      • $(TargetFrameworkVersion) >= 11.0

• Global usings test expectations

  • Updated test/Microsoft.NET.Build.Tests/GivenThatWeWantToGenerateGlobalUsings_DotNet.cs expected generated .GlobalUsings.g.cs content for current target framework behavior.
  • Updated test/Microsoft.NET.Build.Tests/GivenThatWeWantToGenerateGlobalUsings_Worker.cs (It_generates_worker_implicit_usings_and_builds_successfully) to include global using System.Net.Http.Json;.
  • Added coverage in GivenThatWeWantToGenerateGlobalUsings_DotNet.cs to verify System.Net.Http.Json is not generated for net10.0, validating the net11 gate.

<ItemGroup Condition="'$(ImplicitUsings)' == 'true' Or '$(ImplicitUsings)' == 'enable'">
  <Using Include="System.Net.Http" Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework'"/>
  <Using Include="System.Net.Http.Json"
         Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' And $([MSBuild]::VersionGreaterThanOrEquals('$(TargetFrameworkVersion)', '11.0'))" />
</ItemGroup>

[marcpopMSFT]

@copilot make the condition be net11 or higher as this is a breaking change for anyone who's made IDE0005 a higher severity than a message. Also, you need to fix the It_generates_worker_implicit_usings_and_builds_successfully test as it now includes the new using

[Copilot]

@copilot make the condition be net11 or higher as this is a breaking change for anyone who's made IDE0005 a higher severity than a message. Also, you need to fix the `It_generates_worker_implicit_usin...

Updated as requested: System.Net.Http.Json implicit-using is now gated to net11+ and It_generates_worker_implicit_usings_and_builds_successfully now expects it. I also added a net10.0 regression test to verify the gate. Addressed in df98a54 (plus supporting commits bd88889 and 684ef5b).

[baronfel]

@copilot this change broke the run-file tests. Analyze and attempt to fix those as well.

cc @jjonescz

[Copilot]

@copilot this change broke the run-file tests. Analyze and attempt to fix those as well.

cc @jjonescz

Fixed and validated. The run-file regression was in csc-only global usings generation (CSharpCompilerCommand.Generated.cs) missing System.Net.Http.Json, which made RunFileTests_CscOnlyAndApi.CscVsMSBuild fail after the net11+ implicit-using change. Updated it to match MSBuild output and verified targeted run-file + implicit-usings tests pass. Addressed in 76e44fb.

[baronfel]

@marcpopMSFT it looks like Copilot did a good job with the http Using - should we have it go ahead and do the Extensions ones we spoke about during triage as well?

[Copilot]

Pull request overview

This PR aligns Microsoft.NET.Sdk (console/standard SDK) C# implicit-usings behavior with ASP.NET Core for .NET 11+ by implicitly adding System.Net.Http.Json for .NETCoreApp projects targeting 11.0+, and updates tests/templates that assert generated global-usings content.

Changes:

• Add System.Net.Http.Json to default C# implicit usings for .NETCoreApp when TargetFrameworkVersion >= 11.0.
• Update Microsoft.NET.Sdk and Microsoft.NET.Sdk.Worker global-usings generation tests to include the new implicit using for the current TFM (net11).
• Add a regression test ensuring System.Net.Http.Json is not generated when targeting net10.0, and update the dotnet run file.cs CSC-only template to match MSBuild output for net11.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
test/Microsoft.NET.Build.Tests/GivenThatWeWantToGenerateGlobalUsings_Worker.cs	Updates worker implicit-usings expectation to include System.Net.Http.Json for current TFM.
test/Microsoft.NET.Build.Tests/GivenThatWeWantToGenerateGlobalUsings_DotNet.cs	Updates baseline expectations for net11 and adds a net10 gate test to validate the new condition.
src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.CSharp.props	Adds the new conditional implicit using for .NETCoreApp targeting net11+.
src/Cli/dotnet/Commands/Run/CSharpCompilerCommand.Generated.cs	Updates CSC-only auxiliary GlobalUsings template to stay aligned with MSBuild for net11+.

[baronfel]

/ba-g NetAnalyzer crash that's unreleated

[marcpopMSFT]

@marcpopMSFT it looks like Copilot did a good job with the http Using - should we have it go ahead and do the Extensions ones we spoke about during triage as well?

@baronfel talked to @ericstj offline and he says no as they are only pushing the abstractions, not the full E2E.