From e14afd10638f32d0e859e9df52872ad59cdc7931 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Tue, 21 Dec 2021 21:58:13 +0100
Subject: [PATCH] feat: add logging extension for results

---
 .../Extensions/ResultExtensions.cs            | 67 +++++++++++++++++++
 Core/NosSmooth.Core/NosSmooth.Core.csproj     |  1 +
 2 files changed, 68 insertions(+)
 create mode 100644 Core/NosSmooth.Core/Extensions/ResultExtensions.cs

diff --git a/Core/NosSmooth.Core/Extensions/ResultExtensions.cs b/Core/NosSmooth.Core/Extensions/ResultExtensions.cs
new file mode 100644
index 0000000..41c2dae
--- /dev/null
+++ b/Core/NosSmooth.Core/Extensions/ResultExtensions.cs
@@ -0,0 +1,67 @@
+//
+//  ResultExtensions.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Text;
+using Microsoft.Extensions.Logging;
+using Remora.Results;
+
+namespace NosSmooth.Core.Extensions;
+
+/// <summary>
+/// Contains extension methods for <see cref="ResultExtensions"/>.
+/// </summary>
+public static class ResultExtensions
+{
+    /// <summary>
+    /// Logs the given result if it is errorful.
+    /// </summary>
+    /// <param name="logger">The logger.</param>
+    /// <param name="result">The result to log.</param>
+    /// <exception cref="InvalidOperationException">Thrown if the result was unsuccessful.</exception>
+    public static void LogResultError(this ILogger logger, IResult result)
+    {
+        if (result.IsSuccess)
+        {
+            throw new InvalidOperationException("The result was successful, it has to be unsuccessful to log it.");
+        }
+
+        switch (result.Error)
+        {
+            case AggregateError aggregateError:
+                logger.LogAggreggateError(aggregateError);
+                break;
+            default:
+                logger.LogNestedError(result);
+                break;
+        }
+    }
+
+    private static void LogAggreggateError(this ILogger logger, AggregateError error)
+    {
+        foreach (var result in error.Errors)
+        {
+            logger.LogResultError(result);
+        }
+    }
+
+    private static void LogNestedError(this ILogger logger, IResult? result)
+    {
+        if ((result?.IsSuccess ?? true) || result.Error is null)
+        {
+            throw new InvalidOperationException("The result was successful, it has to be unsuccessful to log it.");
+        }
+
+        var stringBuilder = new StringBuilder(result.Error.Message);
+        int index = 0;
+        while ((result = result?.Inner) is not null && result.Error is not null)
+        {
+            stringBuilder.Append($"\n  {index++}: {result.Error.Message}");
+        }
+
+        logger.LogError(stringBuilder.ToString());
+    }
+}
\ No newline at end of file
diff --git a/Core/NosSmooth.Core/NosSmooth.Core.csproj b/Core/NosSmooth.Core/NosSmooth.Core.csproj
index eb756c8..f79deb2 100644
--- a/Core/NosSmooth.Core/NosSmooth.Core.csproj
+++ b/Core/NosSmooth.Core/NosSmooth.Core.csproj
@@ -7,6 +7,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+      <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="6.0.0" />
       <PackageReference Include="Remora.Results" Version="7.1.0" />
     </ItemGroup>
 
-- 
2.48.1