[sdk] Build extension behavior tweaks (#4885)

src/OpenTelemetry.Api/Logs/LoggerProvider.cs

@@ -38,6 +38,13 @@ class LoggerProvider : BaseProvider
 {
     private static readonly NoopLogger NoopLogger = new();
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="LoggerProvider"/> class.
+    /// </summary>
+    protected LoggerProvider()
+    {
+    }
+
     /// <summary>
     /// Gets a logger.
     /// </summary>

src/OpenTelemetry/.publicApi/Stable/net462/PublicAPI.Shipped.txt

@@ -368,7 +368,7 @@ static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddReader<T>(this Op
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, OpenTelemetry.Metrics.MetricStreamConfiguration! metricStreamConfiguration) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, string! name) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Func<System.Diagnostics.Metrics.Instrument!, OpenTelemetry.Metrics.MetricStreamConfiguration?>! viewConfig) -> OpenTelemetry.Metrics.MeterProviderBuilder!
-static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider?
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricPointsPerMetricStream(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricPointsPerMetricStream) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricStreams(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricStreams) -> OpenTelemetry.Metrics.MeterProviderBuilder!
@@ -398,7 +398,7 @@ static OpenTelemetry.Trace.SamplingResult.operator ==(OpenTelemetry.Trace.Sampli
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>! processor) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Func<System.IServiceProvider!, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>!>! implementationFactory) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor<T>(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!
-static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider?
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetErrorStatusOnException(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, bool enabled = true) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetResourceBuilder(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.Resources.ResourceBuilder! resourceBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry/.publicApi/Stable/net6.0/PublicAPI.Shipped.txt

@@ -368,7 +368,7 @@ static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddReader<T>(this Op
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, OpenTelemetry.Metrics.MetricStreamConfiguration! metricStreamConfiguration) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, string! name) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Func<System.Diagnostics.Metrics.Instrument!, OpenTelemetry.Metrics.MetricStreamConfiguration?>! viewConfig) -> OpenTelemetry.Metrics.MeterProviderBuilder!
-static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider?
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricPointsPerMetricStream(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricPointsPerMetricStream) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricStreams(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricStreams) -> OpenTelemetry.Metrics.MeterProviderBuilder!
@@ -398,7 +398,7 @@ static OpenTelemetry.Trace.SamplingResult.operator ==(OpenTelemetry.Trace.Sampli
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>! processor) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Func<System.IServiceProvider!, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>!>! implementationFactory) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor<T>(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!
-static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider?
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetErrorStatusOnException(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, bool enabled = true) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetResourceBuilder(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.Resources.ResourceBuilder! resourceBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry/.publicApi/Stable/netstandard2.0/PublicAPI.Shipped.txt

@@ -368,7 +368,7 @@ static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddReader<T>(this Op
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, OpenTelemetry.Metrics.MetricStreamConfiguration! metricStreamConfiguration) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, string! name) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Func<System.Diagnostics.Metrics.Instrument!, OpenTelemetry.Metrics.MetricStreamConfiguration?>! viewConfig) -> OpenTelemetry.Metrics.MeterProviderBuilder!
-static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider?
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricPointsPerMetricStream(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricPointsPerMetricStream) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricStreams(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricStreams) -> OpenTelemetry.Metrics.MeterProviderBuilder!
@@ -398,7 +398,7 @@ static OpenTelemetry.Trace.SamplingResult.operator ==(OpenTelemetry.Trace.Sampli
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>! processor) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Func<System.IServiceProvider!, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>!>! implementationFactory) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor<T>(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!
-static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider?
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetErrorStatusOnException(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, bool enabled = true) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetResourceBuilder(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.Resources.ResourceBuilder! resourceBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry/.publicApi/Stable/netstandard2.1/PublicAPI.Shipped.txt

@@ -368,7 +368,7 @@ static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddReader<T>(this Op
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, OpenTelemetry.Metrics.MetricStreamConfiguration! metricStreamConfiguration) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, string! instrumentName, string! name) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddView(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Func<System.Diagnostics.Metrics.Instrument!, OpenTelemetry.Metrics.MetricStreamConfiguration?>! viewConfig) -> OpenTelemetry.Metrics.MeterProviderBuilder!
-static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider?
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.Build(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder) -> OpenTelemetry.Metrics.MeterProvider!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricPointsPerMetricStream(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricPointsPerMetricStream) -> OpenTelemetry.Metrics.MeterProviderBuilder!
 static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.SetMaxMetricStreams(this OpenTelemetry.Metrics.MeterProviderBuilder! meterProviderBuilder, int maxMetricStreams) -> OpenTelemetry.Metrics.MeterProviderBuilder!
@@ -398,7 +398,7 @@ static OpenTelemetry.Trace.SamplingResult.operator ==(OpenTelemetry.Trace.Sampli
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>! processor) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Func<System.IServiceProvider!, OpenTelemetry.BaseProcessor<System.Diagnostics.Activity!>!>! implementationFactory) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddProcessor<T>(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!
-static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider?
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.Build(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder) -> OpenTelemetry.Trace.TracerProvider!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.ConfigureResource(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, System.Action<OpenTelemetry.Resources.ResourceBuilder!>! configure) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetErrorStatusOnException(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, bool enabled = true) -> OpenTelemetry.Trace.TracerProviderBuilder!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.SetResourceBuilder(this OpenTelemetry.Trace.TracerProviderBuilder! tracerProviderBuilder, OpenTelemetry.Resources.ResourceBuilder! resourceBuilder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry/CHANGELOG.md

@@ -11,7 +11,13 @@
   `AddInstrumentation` method.
   ([#4873](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4873))
 
-* Allowed metric instrument names to contain `/` characters. ([#4882](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4882))
+* Allowed metric instrument names to contain `/` characters.
+  ([#4882](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4882))
+
+* **Breaking Change** `[Tracer|Meter|Logger]ProviderBuilder.Build` extension
+  will now throw a `NotSupportedException` if invoked on a non-SDK builder type.
+  Previously it would return `null`.
+  ([#4885](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4885))
 
 ## 1.6.0
 

src/OpenTelemetry/Logs/Builder/LoggerProviderBuilderExtensions.cs

@@ -237,6 +237,6 @@ public static LoggerProvider Build(this LoggerProviderBuilder loggerProviderBuil
             return loggerProviderBuilderBase.Build();
         }
 
-        return new LoggerProvider();
+        throw new NotSupportedException($"Build is not supported on '{loggerProviderBuilder?.GetType().FullName ?? "null"}' instances.");
     }
 }

src/OpenTelemetry/Metrics/Builder/MeterProviderBuilderExtensions.cs

@@ -313,14 +313,14 @@ public static MeterProviderBuilder ConfigureResource(this MeterProviderBuilder m
     /// </summary>
     /// <param name="meterProviderBuilder"><see cref="MeterProviderBuilder"/>.</param>
     /// <returns><see cref="MeterProvider"/>.</returns>
-    public static MeterProvider? Build(this MeterProviderBuilder meterProviderBuilder)
+    public static MeterProvider Build(this MeterProviderBuilder meterProviderBuilder)
     {
         if (meterProviderBuilder is MeterProviderBuilderBase meterProviderBuilderBase)
         {
             return meterProviderBuilderBase.InvokeBuild();
         }
 
-        return null;
+        throw new NotSupportedException($"Build is not supported on '{meterProviderBuilder?.GetType().FullName ?? "null"}' instances.");
     }
 
 #if EXPOSE_EXPERIMENTAL_FEATURES

src/OpenTelemetry/Trace/Builder/TracerProviderBuilderExtensions.cs

@@ -249,13 +249,13 @@ public static TracerProviderBuilder AddProcessor(
     /// </summary>
     /// <param name="tracerProviderBuilder"><see cref="TracerProviderBuilder"/>.</param>
     /// <returns><see cref="TracerProvider"/>.</returns>
-    public static TracerProvider? Build(this TracerProviderBuilder tracerProviderBuilder)
+    public static TracerProvider Build(this TracerProviderBuilder tracerProviderBuilder)
     {
         if (tracerProviderBuilder is TracerProviderBuilderBase tracerProviderBuilderBase)
         {
             return tracerProviderBuilderBase.InvokeBuild();
         }
 
-        return null;
+        throw new NotSupportedException($"Build is not supported on '{tracerProviderBuilder?.GetType().FullName ?? "null"}' instances.");
     }
 }

test/OpenTelemetry.Api.Tests/Logs/LoggerProviderTests.cs

@@ -28,7 +28,7 @@ public sealed class LoggerProviderTests
     [Fact]
     public void NoopLoggerReturnedTest()
     {
-        using var provider = new LoggerProvider();
+        using var provider = new NoopLoggerProvider();
 
         var logger = provider.GetLogger(name: "TestLogger", version: "Version");
 
@@ -69,6 +69,10 @@ public void LoggerReturnedWithInstrumentationScopeTest()
         Assert.Null(logger.Version);
     }
 
+    private sealed class NoopLoggerProvider : LoggerProvider
+    {
+    }
+
     private sealed class TestLoggerProvider : LoggerProvider
     {
         protected override bool TryCreateLogger(

test/OpenTelemetry.Tests/Logs/LoggerProviderBuilderExtensionsTests.cs

@@ -179,6 +179,14 @@ public void LoggerProviderBuilderAddProcessorTest()
         }
     }
 
+    [Fact]
+    public void LoggerProviderBuilderCustomImplementationBuildTest()
+    {
+        var builder = new CustomLoggerProviderBuilder();
+
+        Assert.Throws<NotSupportedException>(() => builder.Build());
+    }
+
     private sealed class CustomInstrumentation : IDisposable
     {
         public bool Disposed;
@@ -209,4 +217,12 @@ public override ExportResult Export(in Batch<LogRecord> batch)
             return ExportResult.Success;
         }
     }
+
+    private sealed class CustomLoggerProviderBuilder : LoggerProviderBuilder
+    {
+        public override LoggerProviderBuilder AddInstrumentation<TInstrumentation>(Func<TInstrumentation> instrumentationFactory)
+        {
+            throw new NotImplementedException();
+        }
+    }
 }