From 3654da8be4c4186a3ad8b7c74024099d47e1b24b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Silva?=
 <2493377+askpt@users.noreply.github.com>
Date: Thu, 14 Dec 2023 15:25:16 +0000
Subject: [PATCH] Add documentation.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: André Silva <2493377+askpt@users.noreply.github.com>
---
 .../MetricsHook.cs                            | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/OpenFeature.Contrib.Hooks.Otel/MetricsHook.cs b/src/OpenFeature.Contrib.Hooks.Otel/MetricsHook.cs
index 5e5c8c31..aafdfdbc 100644
--- a/src/OpenFeature.Contrib.Hooks.Otel/MetricsHook.cs
+++ b/src/OpenFeature.Contrib.Hooks.Otel/MetricsHook.cs
@@ -8,6 +8,9 @@
 
 namespace OpenFeature.Contrib.Hooks.Otel
 {
+    /// <summary>
+    /// Represents a hook for capturing metrics related to flag evaluations.
+    /// </summary>
     public class MetricsHook : Hook
     {
         private static readonly AssemblyName AssemblyName = typeof(MetricsHook).Assembly.GetName();
@@ -19,6 +22,9 @@ public class MetricsHook : Hook
         private readonly Counter<double> _evaluationSuccessCounter;
         private readonly Counter<double> _evaluationErrorCounter;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MetricsHook"/> class.
+        /// </summary>
         public MetricsHook()
         {
             var meter = new Meter(InstrumentationName, InstrumentationVersion);
@@ -29,6 +35,16 @@ public MetricsHook()
             _evaluationErrorCounter = meter.CreateCounter<double>(MetricsConstants.ERROR_TOTAL_NAME, MetricsConstants.UNIT, MetricsConstants.ERROR_DESCRIPTION);
         }
 
+        /// <summary>
+        /// Executes before the flag evaluation and captures metrics related to the evaluation.
+        /// The metrics are captured in the following order:
+        /// 1. The active count is incremented. (feature_flag.evaluation_active_count)
+        /// 2. The request count is incremented. (feature_flag.evaluation_requests_total)
+        /// </summary>
+        /// <typeparam name="T">The type of the flag value.</typeparam>
+        /// <param name="context">The hook context.</param>
+        /// <param name="hints">The optional hints.</param>
+        /// <returns>The evaluation context.</returns>
         public override Task<EvaluationContext> Before<T>(HookContext<T> context, IReadOnlyDictionary<string, object> hints = null)
         {
             var tagList = new TagList
@@ -43,6 +59,17 @@ public override Task<EvaluationContext> Before<T>(HookContext<T> context, IReadO
             return base.Before(context, hints);
         }
 
+
+        /// <summary>
+        /// Executes after the flag evaluation and captures metrics related to the evaluation.
+        /// The metrics are captured in the following order:
+        /// 1. The success count is incremented. (feature_flag.evaluation_success_total)
+        /// </summary>
+        /// <typeparam name="T">The type of the flag value.</typeparam>
+        /// <param name="context">The hook context.</param>
+        /// <param name="details">The flag evaluation details.</param>
+        /// <param name="hints">The optional hints.</param>
+        /// <returns>The evaluation context.</returns>
         public override Task After<T>(HookContext<T> context, FlagEvaluationDetails<T> details, IReadOnlyDictionary<string, object> hints = null)
         {
             var tagList = new TagList
@@ -58,6 +85,16 @@ public override Task After<T>(HookContext<T> context, FlagEvaluationDetails<T> d
             return base.After(context, details, hints);
         }
 
+        /// <summary>
+        /// Executes when an error occurs during flag evaluation and captures metrics related to the error.
+        /// The metrics are captured in the following order:
+        /// 1. The error count is incremented. (feature_flag.evaluation_error_total)
+        /// </summary>
+        /// <typeparam name="T">The type of the flag value.</typeparam>
+        /// <param name="context">The hook context.</param>
+        /// <param name="error">The exception that occurred.</param>
+        /// <param name="hints">The optional hints.</param>
+        /// <returns>The evaluation context.</returns>
         public override Task Error<T>(HookContext<T> context, Exception error, IReadOnlyDictionary<string, object> hints = null)
         {
             var tagList = new TagList
@@ -72,6 +109,14 @@ public override Task Error<T>(HookContext<T> context, Exception error, IReadOnly
             return base.Error(context, error, hints);
         }
 
+        /// <summary>
+        /// Executes after the flag evaluation is complete and captures metrics related to the evaluation.
+        /// The active count is decremented. (feature_flag.evaluation_active_count)
+        /// </summary>
+        /// <typeparam name="T">The type of the flag value.</typeparam>
+        /// <param name="context">The hook context.</param>
+        /// <param name="hints">The optional hints.</param>
+        /// <returns>The evaluation context.</returns>
         public override Task Finally<T>(HookContext<T> context, IReadOnlyDictionary<string, object> hints = null)
         {
             var tagList = new TagList