enable otel in tests on demand

Author: majocha

tests/FSharp.Test.Utilities/FSharp.Test.Utilities.fsproj

@@ -15,6 +15,8 @@
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
     <!--Extra xUnit customizations, not required for the test suite to work, but can speed up local test runs and help with debugging.-->
     <DefineConstants>XUNIT_EXTRAS</DefineConstants>
+    <!--Uncomment to enable OpenTelemetry instrumentation for the test suite.-->
+    <!--<DefineConstants>OTEL</DefineConstants>-->
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(BUILDING_USING_DOTNET)' == 'true'">

tests/FSharp.Test.Utilities/XunitHelpers.fs

@@ -155,19 +155,24 @@ type FSharpXunitFramework(sink: IMessageSink) =
         AssemblyResolver.addResolver ()
 #endif
 
+// Uncomment definition in project file to enable OpenTelemetry tracing.
+#if OTEL
     let traceProvider =
         Sdk.CreateTracerProviderBuilder()
                 .AddSource(ActivityNames.FscSourceName)
                 .SetResourceBuilder(
                     ResourceBuilder.CreateDefault().AddService(serviceName="F#", serviceVersion = "1.0.0"))
                 .AddOtlpExporter()
                 .Build()
+#endif
 
     interface IDisposable with
         member _.Dispose() =
             cleanUpTemporaryDirectoryOfThisTestRun ()
+#if OTEL
             traceProvider.ForceFlush() |> ignore
             traceProvider.Dispose()
+#endif
             base.Dispose()
 
     // Group test run under single activity, to make traces more readable.