TracingHook.cs

using OpenFeature.Model;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Diagnostics;
using OpenTelemetry.Trace;
using System.Threading;

namespace OpenFeature.Contrib.Hooks.Otel

{
    /// <summary>
    /// Stub.
    /// </summary>
    public class TracingHook : Hook
    {

        /// <inheritdoc/>
        public override ValueTask AfterAsync<T>(HookContext<T> context, FlagEvaluationDetails<T> details,
            IReadOnlyDictionary<string, object> hints = null, CancellationToken cancellationToken = default)
        {
            Activity.Current?
                .SetTag("feature_flag.key", details.FlagKey)
                .SetTag("feature_flag.variant", details.Variant)
                .SetTag("feature_flag.provider_name", context.ProviderMetadata.Name)
                .AddEvent(new ActivityEvent("feature_flag", tags: new ActivityTagsCollection
                {
                    ["feature_flag.key"] = details.FlagKey,
                    ["feature_flag.variant"] = details.Variant,
                    ["feature_flag.provider_name"] = context.ProviderMetadata.Name
                }));

            return default;
        }

        /// <inheritdoc/>
        public override ValueTask ErrorAsync<T>(HookContext<T> context, System.Exception error,
            IReadOnlyDictionary<string, object> hints = null, CancellationToken cancellationToken = default)
        {
            Activity.Current?.RecordException(error);

            return default;
        }

    }
}