feat!: ErrorType as enum, add ErrorMessage string (#72)

Author: kinyoklion

src/OpenFeatureSDK/Constant/ErrorType.cs

@@ -36,6 +36,16 @@ public enum ErrorType
         /// <summary>
         /// Abnormal execution of the provider
         /// </summary>
-        [Description("GENERAL")] General
+        [Description("GENERAL")] General,
+
+        /// <summary>
+        /// Context does not satisfy provider requirements.
+        /// </summary>
+        [Description("INVALID_CONTEXT")] InvalidContext,
+
+        /// <summary>
+        /// Context does not contain a targeting key and the provider requires one.
+        /// </summary>
+        [Description("TARGETING_KEY_MISSING")] TargetingKeyMissing,
     }
 }

src/OpenFeatureSDK/Error/FeatureProviderException.cs

@@ -1,6 +1,5 @@
 using System;
 using OpenFeatureSDK.Constant;
-using OpenFeatureSDK.Extension;
 
 namespace OpenFeatureSDK.Error
 {
@@ -11,9 +10,9 @@ namespace OpenFeatureSDK.Error
     public class FeatureProviderException : Exception
     {
         /// <summary>
-        /// Description of error that occured when evaluating a flag
+        /// Error that occurred during evaluation
         /// </summary>
-        public string ErrorDescription { get; }
+        public ErrorType ErrorType { get; }
 
         /// <summary>
         /// Initialize a new instance of the <see cref="FeatureProviderException"/> class
@@ -24,19 +23,7 @@ public class FeatureProviderException : Exception
         public FeatureProviderException(ErrorType errorType, string message = null, Exception innerException = null)
             : base(message, innerException)
         {
-            this.ErrorDescription = errorType.GetDescription();
-        }
-
-        /// <summary>
-        /// Initialize a new instance of the <see cref="FeatureProviderException"/> class
-        /// </summary>
-        /// <param name="errorCode">A string representation describing the error that occured</param>
-        /// <param name="message">Exception message</param>
-        /// <param name="innerException">Optional inner exception</param>
-        public FeatureProviderException(string errorCode, string message = null, Exception innerException = null)
-            : base(message, innerException)
-        {
-            this.ErrorDescription = errorCode;
+            this.ErrorType = errorType;
         }
     }
 }

src/OpenFeatureSDK/Extension/ResolutionDetailsExtensions.cs

@@ -6,7 +6,8 @@ internal static class ResolutionDetailsExtensions
     {
         public static FlagEvaluationDetails<T> ToFlagEvaluationDetails<T>(this ResolutionDetails<T> details)
         {
-            return new FlagEvaluationDetails<T>(details.FlagKey, details.Value, details.ErrorType, details.Reason, details.Variant);
+            return new FlagEvaluationDetails<T>(details.FlagKey, details.Value, details.ErrorType, details.Reason,
+                details.Variant, details.ErrorMessage);
         }
     }
 }

src/OpenFeatureSDK/Model/FlagEvalusationDetails.cs src/OpenFeatureSDK/Model/FlagEvaluationDetails.cs

@@ -1,5 +1,4 @@
 using OpenFeatureSDK.Constant;
-using OpenFeatureSDK.Extension;
 
 namespace OpenFeatureSDK.Model
 {
@@ -23,7 +22,16 @@ public class FlagEvaluationDetails<T>
         /// <summary>
         /// Error that occurred during evaluation
         /// </summary>
-        public string ErrorType { get; }
+        public ErrorType ErrorType { get; }
+
+        /// <summary>
+        /// Message containing additional details about an error.
+        /// <para>
+        /// Will be <see langword="null" /> if there is no error or if the provider didn't provide any additional error
+        /// details.
+        /// </para>
+        /// </summary>
+        public string ErrorMessage { get; }
 
         /// <summary>
         /// Describes the reason for the outcome of the evaluation process
@@ -45,30 +53,16 @@ public class FlagEvaluationDetails<T>
         /// <param name="errorType">Error</param>
         /// <param name="reason">Reason</param>
         /// <param name="variant">Variant</param>
-        public FlagEvaluationDetails(string flagKey, T value, ErrorType errorType, string reason, string variant)
-        {
-            this.Value = value;
-            this.FlagKey = flagKey;
-            this.ErrorType = errorType.GetDescription();
-            this.Reason = reason;
-            this.Variant = variant;
-        }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="FlagEvaluationDetails{T}"/> class.
-        /// </summary>
-        /// <param name="flagKey">Feature flag key</param>
-        /// <param name="value">Evaluated value</param>
-        /// <param name="errorType">Error</param>
-        /// <param name="reason">Reason</param>
-        /// <param name="variant">Variant</param>
-        public FlagEvaluationDetails(string flagKey, T value, string errorType, string reason, string variant)
+        /// <param name="errorMessage">Error message</param>
+        public FlagEvaluationDetails(string flagKey, T value, ErrorType errorType, string reason, string variant,
+            string errorMessage = null)
         {
             this.Value = value;
             this.FlagKey = flagKey;
             this.ErrorType = errorType;
             this.Reason = reason;
             this.Variant = variant;
+            this.ErrorMessage = errorMessage;
         }
     }
 }

src/OpenFeatureSDK/Model/ResolutionDetails.cs

@@ -26,6 +26,11 @@ public class ResolutionDetails<T>
         /// </summary>
         public ErrorType ErrorType { get; }
 
+        /// <summary>
+        /// Message containing additional details about an error.
+        /// </summary>
+        public string ErrorMessage { get; }
+
         /// <summary>
         /// Describes the reason for the outcome of the evaluation process
         /// <see cref="Reason"/>
@@ -47,14 +52,16 @@ public class ResolutionDetails<T>
         /// <param name="errorType">Error</param>
         /// <param name="reason">Reason</param>
         /// <param name="variant">Variant</param>
+        /// <param name="errorMessage">Error message</param>
         public ResolutionDetails(string flagKey, T value, ErrorType errorType = ErrorType.None, string reason = null,
-            string variant = null)
+            string variant = null, string errorMessage = null)
         {
             this.Value = value;
             this.FlagKey = flagKey;
             this.ErrorType = errorType;
             this.Reason = reason;
             this.Variant = variant;
+            this.ErrorMessage = errorMessage;
         }
     }
 }

src/OpenFeatureSDK/OpenFeatureClient.cs

@@ -257,9 +257,9 @@ private async Task<FlagEvaluationDetails<T>> EvaluateFlag<T>(
             catch (FeatureProviderException ex)
             {
                 this._logger.LogError(ex, "Error while evaluating flag {FlagKey}. Error {ErrorType}", flagKey,
-                    ex.ErrorDescription);
-                evaluation = new FlagEvaluationDetails<T>(flagKey, defaultValue, ex.ErrorDescription, Reason.Error,
-                    string.Empty);
+                    ex.ErrorType.GetDescription());
+                evaluation = new FlagEvaluationDetails<T>(flagKey, defaultValue, ex.ErrorType, Reason.Error,
+                    string.Empty, ex.Message);
                 await this.TriggerErrorHooks(allHooksReversed, hookContext, ex, options);
             }
             catch (Exception ex)

test/OpenFeatureSDK.Tests/FeatureProviderExceptionTests.cs

@@ -2,6 +2,7 @@
 using FluentAssertions;
 using OpenFeatureSDK.Constant;
 using OpenFeatureSDK.Error;
+using OpenFeatureSDK.Extension;
 using Xunit;
 
 namespace OpenFeatureSDK.Tests
@@ -17,16 +18,16 @@ public class FeatureProviderExceptionTests
         public void FeatureProviderException_Should_Resolve_Description(ErrorType errorType, string errorDescription)
         {
             var ex = new FeatureProviderException(errorType);
-            ex.ErrorDescription.Should().Be(errorDescription);
+            ex.ErrorType.GetDescription().Should().Be(errorDescription);
         }
 
         [Theory]
-        [InlineData("OUT_OF_CREDIT", "Subscription has expired, please renew your subscription.")]
-        [InlineData("Exceed quota", "User has exceeded the quota for this feature.")]
-        public void FeatureProviderException_Should_Allow_Custom_ErrorCode_Messages(string errorCode, string message)
+        [InlineData(ErrorType.General, "Subscription has expired, please renew your subscription.")]
+        [InlineData(ErrorType.ProviderNotReady, "User has exceeded the quota for this feature.")]
+        public void FeatureProviderException_Should_Allow_Custom_ErrorCode_Messages(ErrorType errorCode, string message)
         {
             var ex = new FeatureProviderException(errorCode, message, new ArgumentOutOfRangeException("flag"));
-            ex.ErrorDescription.Should().Be(errorCode);
+            ex.ErrorType.Should().Be(errorCode);
             ex.Message.Should().Be(message);
             ex.InnerException.Should().BeOfType<ArgumentOutOfRangeException>();
         }