Add tests for TracerProviderBuilderBase.

test/OpenTelemetry.Tests/Trace/TracerProviderBuilderBaseTests.cs

@@ -0,0 +1,83 @@
+// <copyright file="TracerProviderBuilderBaseTests.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+#nullable enable
+
+using Xunit;
+
+namespace OpenTelemetry.Trace.Tests;
+
+public class TracerProviderBuilderBaseTests
+{
+    [Fact]
+    public void AddInstrumentationInvokesFactoryTest()
+    {
+        bool factoryInvoked = false;
+
+        var instrumentation = new TestTracerProviderBuilder();
+        instrumentation.AddInstrumentationViaProtectedMethod(() =>
+        {
+            factoryInvoked = true;
+
+            return null;
+        });
+
+        using var provider = instrumentation.Build();
+
+        Assert.True(factoryInvoked);
+    }
+
+    [Fact]
+    public void AddInstrumentationValidatesInputTest()
+    {
+        Assert.Throws<ArgumentException>(() =>
+        {
+            new TestTracerProviderBuilder().AddInstrumentationViaProtectedMethod(
+                name: null,
+                version: "1.0.0",
+                factory: () => null);
+        });
+
+        Assert.Throws<ArgumentException>(() =>
+        {
+            new TestTracerProviderBuilder().AddInstrumentationViaProtectedMethod(
+                name: "name",
+                version: null,
+                factory: () => null);
+        });
+
+        Assert.Throws<ArgumentNullException>(() =>
+        {
+            new TestTracerProviderBuilder().AddInstrumentationViaProtectedMethod(
+                name: "name",
+                version: "1.0.0",
+                factory: null);
+        });
+    }
+
+    private sealed class TestTracerProviderBuilder : TracerProviderBuilderBase
+    {
+        public void AddInstrumentationViaProtectedMethod(Func<object?> factory)
+        {
+            this.AddInstrumentation("MyName", "MyVersion", factory);
+        }
+
+        public void AddInstrumentationViaProtectedMethod(string? name, string? version, Func<object?>? factory)
+        {
+            this.AddInstrumentation(name!, version!, factory!);
+        }
+    }
+}