[AspNetCore] Avoid adding tags for traces

[martincostello]

See martincostello#2 (review).

Relates to #3808.

Changes

Avoid adding tags for ASP.NET Core activities where ASP.NET Core has native support to add them itself.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.99%. Comparing base (dc7e36a) to head (42d6789).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3993      +/-   ##
==========================================
+ Coverage   75.92%   75.99%   +0.06%     
==========================================
  Files         466      466              
  Lines       18631    18635       +4     
==========================================
+ Hits        14146    14161      +15     
+ Misses       4485     4474      -11     

Flag	Coverage Δ
unittests-Instrumentation.AspNet	76.99% <ø> (ø)
unittests-Instrumentation.AspNetCore	70.79% <100.00%> (+0.34%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...umentation.AspNetCore/AspNetCoreInstrumentation.cs	100.00% <100.00%> (ø)
...eInstrumentationTracerProviderBuilderExtensions.cs	95.55% <100.00%> (-0.19%)	⬇️
...tation.AspNetCore/Implementation/HttpInListener.cs	74.50% <100.00%> (+1.22%)	⬆️

... and 4 files with indirect coverage changes

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

Updates ASP.NET Core tracing instrumentation to avoid setting certain HTTP semantic-convention tags when ASP.NET Core can provide them natively (targeting improved performance on newer runtimes).

Changes:

• Add runtime/app-context gating to skip setting selected HTTP tags when ASP.NET Core native OpenTelemetry data is enabled.
• Refactor event handling and small code-style cleanups in instrumentation wiring.
• Document the behavior and the relevant AppContext switch in the AspNetCore instrumentation changelog.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs	Adds .NET 10 gating + AppContext switch check to conditionally avoid manual tag population.
src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md	Documents the new behavior and the AppContext switch guidance.
src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentationTracerProviderBuilderExtensions.cs	Minor formatting/comment wording updates.
src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs	Minor lambda/dispose style cleanup.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 7 days.