refactor: change to delegate

Author: rungwiroon

src/Codehard.Functional/Codehard.Functional.AspNetCore/ControllerExtensions.cs

@@ -48,7 +48,7 @@ private static IActionResult MapErrorToActionResult(Error err)
     public static IActionResult MatchToResult<T>(
         this Fin<T> fin,
         HttpStatusCode successStatusCode = HttpStatusCode.OK,
-        ILogger? logger = default)
+        ILogger? logger = null)
     {
         return fin
             .Match(
@@ -61,7 +61,7 @@ public static IActionResult MatchToResult<T>(
                             logger?.Log(hre);
                             return MapErrorToActionResult(hre);
                         default:
-                            logger?.Log(err, exceptionHandler: WebApiExceptionHandler.Instance);
+                            logger?.Log(err, exceptionHandler: WebApiExceptionHandler.Handle);
                             return MapErrorToActionResult(err);
                     }
                 });
@@ -74,7 +74,7 @@ public static IActionResult MatchToResult<T>(
     public static IActionResult MatchToResult<T>(
         this Fin<Option<T>> fin,
         HttpStatusCode successStatusCode = HttpStatusCode.OK,
-        ILogger? logger = default)
+        ILogger? logger = null)
     {
         return fin
             .Match(
@@ -107,7 +107,7 @@ public static IActionResult MatchToResult<T>(
     public static ValueTask<IActionResult> RunToResultAsync<T>(
         this Aff<T> aff,
         HttpStatusCode successStatusCode = HttpStatusCode.OK,
-        ILogger? logger = default)
+        ILogger? logger = null)
     {
         return aff
             .Run()
@@ -123,7 +123,7 @@ public static ValueTask<IActionResult> RunToResultAsync<T>(
     public static IActionResult RunToResult<T>(
         this Eff<T> eff,
         HttpStatusCode successStatusCode = HttpStatusCode.OK,
-        ILogger? logger = default)
+        ILogger? logger = null)
     {
         return eff
             .Run()

src/Codehard.Functional/Codehard.Functional.AspNetCore/LoggingExtesions.cs

@@ -46,18 +46,18 @@ public static void Log(this ILogger logger, HttpResultError error)
 }
 
 /// <summary>
-/// Provides a centralized mechanism for handling exceptions and logging errors in a web API context.
-/// Implements the <see cref="IExceptionHandler"/> interface to process and log errors with optional context-specific behavior.
+/// Provides methods to handle and log exceptions in a structured format for web APIs.
 /// </summary>
-public class WebApiExceptionHandler : IExceptionHandler
+public static class WebApiExceptionHandler
 {
-    private static WebApiExceptionHandler instance = new();
-    
-    public static WebApiExceptionHandler Instance => instance;
-    
-    private WebApiExceptionHandler() { }
-    
-    public Unit Handle(Error error, ILogger logger, LogLevel logLevel = LogLevel.Information)
+    /// <summary>
+    /// Handles the specified error by logging it using the provided logger
+    /// and applying the given log level.
+    /// </summary>
+    /// <param name="logger">The logger used to record the error information.</param>
+    /// <param name="error">The error instance containing details to handle and log.</param>
+    /// <param name="logLevel">The severity level of the log entry. Defaults to Information.</param>
+    public static void Handle(ILogger logger, Error error, LogLevel logLevel = LogLevel.Information)
     {
         error.Exception.Match(
             Some: ex =>
@@ -83,7 +83,5 @@ public Unit Handle(Error error, ILogger logger, LogLevel logLevel = LogLevel.Inf
                     logger.Log(logLevel, "{Code} : {Message}", error.Code, error.Message);
                 }
             });
-
-        return unit;
     }
 }

src/Codehard.Functional/Codehard.Functional.Logger/DefaultExceptionHandler.cs

@@ -3,20 +3,17 @@
 namespace Codehard.Functional.Logger;
 
 /// <summary>
-/// Provides a default implementation for handling exceptions in a logging context.
-/// This class is intended to standardize how exceptions and errors are logged
-/// based on the provided parameters such as the error details, logger instance,
-/// and log level.
+/// Provides a default exception handling mechanism for logging errors using an <see cref="ILogger"/> instance.
 /// </summary>
-public class DefaultExceptionHandler : IExceptionHandler
+public static class DefaultExceptionHandler
 {
-    private static DefaultExceptionHandler instance = new DefaultExceptionHandler();
-    
-    public static DefaultExceptionHandler Instance => instance;
-    
-    private DefaultExceptionHandler() { }
-    
-    public Unit Handle(Error error, ILogger logger, LogLevel logLevel = LogLevel.Information)
+    /// <summary>
+    /// Handles logging of an error using the specified <see cref="ILogger"/> instance.
+    /// </summary>
+    /// <param name="logger">The logger used to log the error information.</param>
+    /// <param name="error">The error to be logged, containing an optional exception and message.</param>
+    /// <param name="logLevel">The logging level to use, defaults to <see cref="LogLevel.Information"/>.</param>
+    public static void Handle(ILogger logger, Error error, LogLevel logLevel = LogLevel.Information)
     {
         error.Exception.Match(
             Some: ex =>
@@ -35,7 +32,5 @@ public Unit Handle(Error error, ILogger logger, LogLevel logLevel = LogLevel.Inf
                     logger.Log(logLevel, "{Code} : {Message}", error.Code, error.Message);
                 }
             });
-
-        return unit;
     }
 }

src/Codehard.Functional/Codehard.Functional.Logger/IExceptionHandler.cs

@@ -11,16 +11,24 @@ private static Unit Log(
         this ILogger logger,
         Option<Error> errorOpt,
         LogLevel logLevel = LogLevel.Information,
-        IExceptionHandler? exceptionHandler = null)
+        Action<ILogger, Error, LogLevel>? exceptionHandler = null)
     {
         return
             errorOpt.Match(
                 Some: error =>
                 {
                     Log(logger, error.Inner, logLevel);
 
-                    return exceptionHandler?.Handle(error, logger, logLevel) ??
-                           DefaultExceptionHandler.Instance.Handle(error, logger, logLevel);
+                    if (exceptionHandler != null)
+                    {
+                        exceptionHandler?.Invoke(logger, error, logLevel);
+                    }
+                    else
+                    {
+                        DefaultExceptionHandler.Handle(logger, error, logLevel);
+                    }
+
+                    return unit;
                 },
                 None: unit);
     }
@@ -56,7 +64,7 @@ public static Unit Log(
         this ILogger logger,
         Error error,
         LogLevel logLevel = LogLevel.Information,
-        IExceptionHandler? exceptionHandler = null)
+        Action<ILogger, Error, LogLevel>? exceptionHandler = null)
     {
         Log(logger, Some(error), logLevel, exceptionHandler);
 
@@ -76,7 +84,7 @@ public static Error DoLog(
         this ILogger logger,
         Error error,
         LogLevel logLevel = LogLevel.Information,
-        IExceptionHandler? exceptionHandler = null)
+        Action<ILogger, Error, LogLevel>? exceptionHandler = null)
     {
         Log(logger, Some(error), logLevel, exceptionHandler);
 
@@ -96,7 +104,7 @@ public static Fin<T> LogIfFail<T>(
         this ILogger logger,
         Fin<T> fin,
         LogLevel logLevel = LogLevel.Information,
-        IExceptionHandler? exceptionHandler = null)
+        Action<ILogger, Error, LogLevel>? exceptionHandler = null)
     {
         fin.IfFail(err => Log(logger, err, logLevel, exceptionHandler));