Fix warnings and cleanup.

[rajkumar-rangaraj]

Fix Issue # .

Changes

(Please provide a brief description of the changes here.)

Checklist

• I ran Unit Tests locally.
• CHANGELOG.md updated with one line description of the fix, and a link to the original issue if available.

For significant contributions please make sure you have completed the following items:

• Design discussion issue #
• Changes in public surface reviewed

The PR will trigger build, unit tests, and functional tests automatically. Please follow these instructions to build and test locally.

Notes for authors:

• FxCop and other analyzers will fail the build. To see these errors yourself, compile localy using the Release configuration.

[Copilot]

Pull request overview

This PR primarily addresses analyzer warnings via updated null-check patterns / API usage, and performs a large cleanup by removing multiple legacy NETCORE test projects and their associated content.

Changes:

• Updated several components to use newer null-check APIs (ArgumentNullException.ThrowIfNull) and newer overloads (e.g., string.Replace(..., StringComparison)), gated by target framework.
• Improved a few implementations for correctness/perf (e.g., MetricIdentifier invalid-char detection; safer config-file reading).
• Removed multiple NETCORE test projects (AspNetCore.Tests, WorkerService.Tests, FunctionalTests.*) and associated test assets.

Reviewed changes

Copilot reviewed 129 out of 129 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
WEB/Src/Web/Web/WebTestActivityProcessor.cs	Simplifies tag null/empty checks.
WEB/Src/Web/Web/UserActivityProcessor.cs	Simplifies tag null/empty checks.
WEB/Src/Web/Web/SyntheticUserAgentActivityProcessor.cs	Avoids repeated separator allocations; simplifies tag check.
WEB/Src/Web/Web/SessionActivityProcessor.cs	Simplifies tag null/empty checks.
WEB/Src/Web/Web/ClientIpHeaderActivityProcessor.cs	Simplifies tag null/empty checks.
WEB/Src/Web/Web/AuthenticatedUserIdActivityProcessor.cs	Simplifies tag null/empty checks.
WEB/Src/Web/Web/AccountIdActivityProcessor.cs	Simplifies tag null/empty checks.
NETCORE/src/Microsoft.ApplicationInsights.AspNetCore/JavaScriptSnippet.cs	Adds TFMs guards for null checks and string operations.
BASE/src/Microsoft.ApplicationInsights/TelemetryClientExtensions.cs	Uses ThrowIfNull under NET6+.
BASE/src/Microsoft.ApplicationInsights/TelemetryClient.cs	Adjusts exception defaults; adds TFMs guards; adds analyzer suppressions for exception reconstruction.
BASE/src/Microsoft.ApplicationInsights/Metrics/MetricIdentifier.cs	Uses SearchValues under NET8+; adjusts Equals(object) signature/name.
BASE/src/Microsoft.ApplicationInsights/Internal/FeatureMetricEmissionHelper.cs	Updates IMDS fetch call signature; changes OS normalization behavior.
BASE/src/Microsoft.ApplicationInsights/Extensibility/TelemetryConfiguration.cs	Uses ThrowIfNull under NET6+.
BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/SelfDiagnosticsConfigParser.cs	Reads config using actual bytes read; uses generic Enum.Parse under NETCOREAPP.
BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/OperationHolder.cs	Condenses null-checks into ?? throw.
BASE/src/Microsoft.ApplicationInsights/DataContracts/ExceptionTelemetry.cs	Adds analyzer suppression for required generic exception reconstruction.
.publicApi/Microsoft.ApplicationInsights.dll/Stable/PublicAPI.Unshipped.txt	Updates public API signature metadata for Equals(object obj).
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/sample-appsettings.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-instrumentation-key.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-instrumentation-key-new.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-endpoint-address.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-developer-mode.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-connection-string.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-connection-string-and-instrumentation-key.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-all-settings-true.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-all-settings-false.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/content/config-all-default.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/appsettings.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/WorkerServiceAadIntegrationTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/Worker.cs	Deleted legacy test harness code.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/Microsoft.ApplicationInsights.WorkerService.Tests.csproj	Deleted legacy test project.
NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/FunctionalTests.cs	Deleted legacy functional tests.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-instrumentation-key.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-instrumentation-key-new.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-endpoint-address.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-developer-mode.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-connection-string.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-connection-string-and-instrumentation-key.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-all-settings-true.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-all-settings-false.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/content/config-all-default.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/appsettings.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TestTelemetryModule.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/WebUserTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/WebSessionTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/SyntheticTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/RoleNameContainerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/OperationNameTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/DomainNameRoleInstanceTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/ComponentVersionTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/ClientIpHeaderTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/AzureAppServiceRoleNameFromHostNameHeaderInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/TelemetryInitializers/AspNetCoreEnvironmentTelemetryInitializerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/SdkVersionTestUtils.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/RequestTrackingTelemetryModuleTest.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Properties/launchSettings.json	Deleted legacy test asset.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Microsoft.ApplicationInsights.AspNetCore.Tests.csproj	Deleted legacy test project.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Logging/ApplicationInsightsLoggerTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/JavaScript/ApplicationInsightsJavaScriptTest.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/HttpHeadersUtilitiesTest.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Helpers/MockApplicationIdProvider.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Helpers/HttpContextAccessorHelper.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Helpers/CommonMocks.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/HeadersUtilitiesTest.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/FakeTelemetryProcessorWithImportingConstructor.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/FakeTelemetryProcessor.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/FakeTelemetryInitializer.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/FakeTelemetryChannel.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/HttpRequestExtensionsTest.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsServiceOptionsTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsExtensionsTests/MockLoggingFactory.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsExtensionsTests/IServiceProviderExtensions.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsExtensionsTests/BaseTestClass.cs	Deleted legacy test harness base.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsExtensionsTests/AddApplicationInsightsSettingsTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensions/ApplicationInsightsAadIntegrationTests.cs	Deleted legacy integration tests.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensibility/Implementation/Tracing/TestEventListener.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensibility/Implementation/Tracing/EventSourceTests.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Extensibility/Implementation/Tracing/AspNetEventSourceTests.cs	Deleted legacy test coverage.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/EnvironmentHelper.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/AspNetCoreMajorVersion.cs	Deleted legacy test helper.
NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/App.config	Deleted legacy test asset.
NETCORE/test/FunctionalTests.WebApi.Tests/xunit.runner.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.WebApi.Tests/appsettings.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.WebApi.Tests/appsettings.Development.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.WebApi.Tests/Startup.cs	Deleted legacy functional test host startup.
NETCORE/test/FunctionalTests.WebApi.Tests/Properties/launchSettings.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTests.WebApi.Tests.csproj	Deleted legacy functional test project.
NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTest/RequestDependencyCorrelationTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTest/RequestCorrelationTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTest/RequestCollectionTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTest/MultipleWebHostsTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.WebApi.Tests/Controllers/ValuesController.cs	Deleted legacy functional test host controller.
NETCORE/test/FunctionalTests.WebApi.Tests/Controllers/ExceptionController.cs	Deleted legacy functional test host controller.
NETCORE/test/FunctionalTests.WebApi.Tests/Controllers/DependencyController.cs	Deleted legacy functional test host controller.
NETCORE/test/FunctionalTests.Utils/TelemetryTestsBase.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/TelemetryItemFactory.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/TelemetryHttpListenerObservable.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/TelemetryExtensions.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/Properties/launchSettings.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.Utils/InProcessServer.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/HttpListenerObservableBase.cs	Deleted legacy functional test utilities.
NETCORE/test/FunctionalTests.Utils/FunctionalTests.Utils.csproj	Deleted legacy functional test utilities project.
NETCORE/test/FunctionalTests.MVC.Tests/xunit.runner.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/bundleconfig.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/bower.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/appsettings.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/appsettings.Development.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/_ViewStart.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/_ViewImports.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Shared/_ValidationScriptsPartial.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Shared/_Layout.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Shared/Error.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Home/Index.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Home/Contact.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Views/Home/About.cshtml	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Startup.cs	Deleted legacy functional test host startup.
NETCORE/test/FunctionalTests.MVC.Tests/Properties/launchSettings.json	Deleted legacy functional test asset.
NETCORE/test/FunctionalTests.MVC.Tests/Models/ErrorViewModel.cs	Deleted legacy functional test host model.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTests.MVC.Tests.csproj	Deleted legacy functional test project.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTest/TelemetryModuleWorkingMvcTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTest/RequestTelemetryMvcTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTest/ExceptionTelemetryMvcTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTest/DependencyTelemetryMvcTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTest/CorrelationMvcTests.cs	Deleted legacy functional test coverage.
NETCORE/test/FunctionalTests.MVC.Tests/Controllers/HomeController.cs	Deleted legacy functional test host controller.
NETCORE/test/FunctionalTests.MVC.Tests/.bowerrc	Deleted legacy functional test asset.

Comments suppressed due to low confidence (5)

NETCORE/test/FunctionalTests.WebApi.Tests/FunctionalTests.WebApi.Tests.csproj:1

• This test project is being removed, but NETCORE/ApplicationInsights.AspNetCore.sln still references test\\FunctionalTests.WebApi.Tests\\FunctionalTests.WebApi.Tests.csproj (solution line ~52). Update the solution/build inputs accordingly or keep the project to avoid missing-project failures.
  NETCORE/test/FunctionalTests.MVC.Tests/FunctionalTests.MVC.Tests.csproj:1
• This test project is being removed, but NETCORE/ApplicationInsights.AspNetCore.sln still references test\\FunctionalTests.MVC.Tests\\FunctionalTests.MVC.Tests.csproj (solution line ~50). Update the solution/build inputs accordingly or keep the project to avoid missing-project failures.
  NETCORE/test/FunctionalTests.Utils/FunctionalTests.Utils.csproj:1
• This project is being removed, but NETCORE/ApplicationInsights.AspNetCore.sln still references test\\FunctionalTests.Utils\\FunctionalTests.Utils.csproj (solution line ~48). Update the solution/build inputs accordingly or keep the project to avoid missing-project failures.
  NETCORE/test/Microsoft.ApplicationInsights.AspNetCore.Tests/Microsoft.ApplicationInsights.AspNetCore.Tests.csproj:1
• This test project is being removed, but NETCORE/ApplicationInsights.AspNetCore.sln still references test\\Microsoft.ApplicationInsights.AspNetCore.Tests\\Microsoft.ApplicationInsights.AspNetCore.Tests.csproj (solution line ~22). Update the solution/build inputs to remove the reference (or keep the project) to avoid solution-based builds failing due to a missing project file.
  NETCORE/test/Microsoft.ApplicationInsights.WorkerService.Tests/Microsoft.ApplicationInsights.WorkerService.Tests.csproj:1
• This test project is being removed, but NETCORE/ApplicationInsights.AspNetCore.sln still references test\\Microsoft.ApplicationInsights.WorkerService.Tests\\Microsoft.ApplicationInsights.WorkerService.Tests.csproj (solution line ~30). Update the solution/build inputs to remove the reference (or keep the project) to prevent solution-based builds from breaking.

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