Adding empty span.

Signed-off-by: André Silva <[email protected]>

test/OpenFeature.Tests/Hooks/TracingHookTests.cs

@@ -72,6 +72,26 @@ await tracingHook.AfterAsync(ctx,
         Assert.Contains(new KeyValuePair<string, object?>("feature_flag.provider_name", "my-provider"), ev.Tags);
     }
 
+    [Fact]
+    public async Task TestAfter_NoSpan()
+    {
+        // Arrange
+        var tracingHook = new TracingHook();
+        var evaluationContext = EvaluationContext.Empty;
+        var ctx = new HookContext<string>("my-flag", "foo", Constant.FlagValueType.String,
+            new ClientMetadata("my-client", "1.0"), new Metadata("my-provider"), evaluationContext);
+
+        // Act
+        await tracingHook.AfterAsync(ctx,
+            new FlagEvaluationDetails<string>("my-flag", "foo", Constant.ErrorType.None, "STATIC", "default"),
+            new Dictionary<string, object>());
+
+        this._tracerProvider.ForceFlush();
+
+        // Assert
+        Assert.Empty(this._exportedItems);
+    }
+
     [Fact]
     public async Task TestError()
     {
@@ -100,4 +120,23 @@ public async Task TestError()
 
         Assert.Contains(new KeyValuePair<string, object?>("exception.message", "unexpected error"), ev.Tags);
     }
+
+    [Fact]
+    public async Task TestError_NoSpan()
+    {
+        // Arrange
+        var tracingHook = new TracingHook();
+        var evaluationContext = EvaluationContext.Empty;
+        var ctx = new HookContext<string>("my-flag", "foo", Constant.FlagValueType.String,
+            new ClientMetadata("my-client", "1.0"), new Metadata("my-provider"), evaluationContext);
+
+        // Act
+        await tracingHook.ErrorAsync(ctx, new Exception("unexpected error"),
+            new Dictionary<string, object>());
+
+        this._tracerProvider.ForceFlush();
+
+        // Assert
+        Assert.Empty(this._exportedItems);
+    }
 }