Edge case fix - when we merge operationresults

and one class doesn't have a logger - we now log

Author: SharePointRadi

src/OneBitSoftware.Utilities.OperationResult/OperationResult.cs

@@ -93,8 +93,18 @@ public OperationResult AppendErrors(OperationResult otherOperationResult)
         {
             if (otherOperationResult is null) return this;
 
-            // Append the error message without logging (presuming that there is already a log message).
-            foreach (var error in otherOperationResult.Errors) this.AppendErrorInternal(error);
+            foreach (var error in otherOperationResult.Errors)
+            {
+                this.AppendErrorInternal(error);
+
+                // Logs messages if the other operation result does not have a logger
+                // BUG: We don't know the severity of the message and need to assume a level.
+                // The task is to make IOperationError have info about the severity, so it can be used here
+                if (this._logger is not null && otherOperationResult._logger is null)
+                {
+                    this._logger.Log(LogLevel.Error, error.Message);
+                }
+            }
 
             return this;
         }

tests/OneBitSoftware.Utilities.OperationResultTests/OperationResultAppendErrorsTests.cs

@@ -111,4 +111,54 @@ public void AppendErrorsStringInt_ShouldListAllErrors()
         Assert.NotNull(operationResultBase.Errors.Single(r => r.Message.Equals(message2)));
         Assert.NotNull(operationResultBase.Errors.Single(r => r.Details is not null && r.Details.Equals(detail2)));
     }
+
+    [Fact]
+    public void AppendErrors_ShouldLogWhenCreatedWithALogger()
+    {
+        // Arrange
+        var testLogger = new TestLogger();
+        var operationResultNoLogger = new OperationResult();
+        var operationResultWithLogger = new OperationResult(testLogger);
+
+        // Act
+        operationResultNoLogger.AppendError("test");
+        operationResultWithLogger.AppendErrors(operationResultNoLogger);
+
+        // Assert
+        Assert.Equal(1, testLogger.LogMessages.Count);
+    }
+
+    [Fact]
+    public void AppendErrors_ShouldLogOnceWhenCreatedWithALogger()
+    {
+        // Arrange
+        var testLogger = new TestLogger();
+        var operationResultWithLogger = new OperationResult(testLogger);
+        var operationResultWithLogger2 = new OperationResult(testLogger);
+
+        // Act
+        operationResultWithLogger2.AppendError("test");
+        operationResultWithLogger.AppendErrors(operationResultWithLogger2);
+
+        // Assert
+        Assert.Equal(1, testLogger.LogMessages.Count);
+    }
+
+
+
+    [Fact]
+    public void AppendErrors_ShouldLogWhenCreatedWithNoLogger()
+    {
+        // Arrange
+        var testLogger = new TestLogger();
+        var operationResultNoLogger = new OperationResult();
+        var operationResultWithLogger = new OperationResult(testLogger);
+
+        // Act
+        operationResultWithLogger.AppendError("test");
+        operationResultNoLogger.AppendErrors(operationResultNoLogger);
+
+        // Assert
+        Assert.Equal(1, testLogger.LogMessages.Count);
+    }
 }

tests/OneBitSoftware.Utilities.OperationResultTests/TestLogger.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+
+namespace OneBitSoftware.Utilities.OperationResultTests
+{
+    public class TestLogger : ILogger
+    {
+        private readonly List<string> _logMessages = new List<string>();
+
+        public IReadOnlyList<string> LogMessages => _logMessages.AsReadOnly();
+
+        public IDisposable BeginScope<TState>(TState state) => null;
+
+        public bool IsEnabled(LogLevel logLevel) => true;
+
+        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
+        {
+            if (formatter != null)
+            {
+                _logMessages.Add(formatter(state, exception));
+            }
+        }
+    }
+}