Added unit tests for SuppressInstrumentationScope (#1909)

* Added unit tests for SuppressInstrumentationScope

* Trigger CI

test/OpenTelemetry.Tests/SuppressInstrumentationTest.cs

@@ -14,6 +14,7 @@
 // limitations under the License.
 // </copyright>
 
+using System.Threading.Tasks;
 using Xunit;
 
 namespace OpenTelemetry.Tests
@@ -43,5 +44,73 @@ namespace OpenTelemetry.Tests
 
             Assert.False(Sdk.SuppressInstrumentation);
         }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData(false)]
+        [InlineData(true)]
+        public void SuppressInstrumentationBeginTest(bool? shouldBegin)
+        {
+            Assert.False(Sdk.SuppressInstrumentation);
+
+            using var scope = shouldBegin.HasValue ? SuppressInstrumentationScope.Begin(shouldBegin.Value) : SuppressInstrumentationScope.Begin();
+            if (shouldBegin.HasValue)
+            {
+                Assert.Equal(shouldBegin.Value, Sdk.SuppressInstrumentation);
+            }
+            else
+            {
+                Assert.True(Sdk.SuppressInstrumentation); // Default behavior is to pass true and suppress the instrumentation
+            }
+        }
+
+        [Fact]
+        public async void SuppressInstrumentationScopeEnterIsLocalToAsyncFlow()
+        {
+            Assert.False(Sdk.SuppressInstrumentation);
+
+            // SuppressInstrumentationScope.Enter called inside the task is only applicable to this async flow
+            await Task.Factory.StartNew(() =>
+            {
+                Assert.False(Sdk.SuppressInstrumentation);
+                SuppressInstrumentationScope.Enter();
+                Assert.True(Sdk.SuppressInstrumentation);
+            });
+
+            Assert.False(Sdk.SuppressInstrumentation); // Changes made by SuppressInstrumentationScope.Enter in the task above are not reflected here as it's not part of the same async flow
+        }
+
+        [Fact]
+        public void DecrementIfTriggeredOnlyWorksInReferenceCountingMode()
+        {
+            // Instrumentation is not suppressed, DecrementIfTriggered is a no op
+            Assert.False(Sdk.SuppressInstrumentation);
+            SuppressInstrumentationScope.DecrementIfTriggered();
+            Assert.False(Sdk.SuppressInstrumentation);
+
+            // Instrumentation is suppressed in reference counting mode, DecrementIfTriggered should work
+            SuppressInstrumentationScope.Enter();
+            Assert.True(Sdk.SuppressInstrumentation);
+            SuppressInstrumentationScope.DecrementIfTriggered();
+            Assert.False(Sdk.SuppressInstrumentation); // Instrumentation is not suppressed anymore
+        }
+
+        [Fact]
+        public void IncrementIfTriggeredOnlyWorksInReferenceCountingMode()
+        {
+            // Instrumentation is not suppressed, IncrementIfTriggered is a no op
+            Assert.False(Sdk.SuppressInstrumentation);
+            SuppressInstrumentationScope.IncrementIfTriggered();
+            Assert.False(Sdk.SuppressInstrumentation);
+
+            // Instrumentation is suppressed in reference counting mode, IncrementIfTriggered should work
+            SuppressInstrumentationScope.Enter();
+            SuppressInstrumentationScope.IncrementIfTriggered();
+            Assert.True(Sdk.SuppressInstrumentation);
+            SuppressInstrumentationScope.DecrementIfTriggered();
+            Assert.True(Sdk.SuppressInstrumentation); // Instrumentation is still suppressed as IncrementIfTriggered incremented the slot count after Enter, need to decrement the slot count again to enable instrumentation
+            SuppressInstrumentationScope.DecrementIfTriggered();
+            Assert.False(Sdk.SuppressInstrumentation); // Instrumentation is not suppressed anymore
+        }
     }
 }