Fix truncation length and strengthen fallback test assertion

framework/src/Volo.Abp.Core/Microsoft/Extensions/Logging/AbpLoggerExtensions.cs

@@ -100,6 +100,7 @@ public static class AbpLoggerExtensions
     }
 
     private const int MaxDataValueLength = 4096;
+    private const string TruncationSuffix = "...(truncated)";
 
     private static string FormatDataValue(object? value)
     {
@@ -119,7 +120,7 @@ public static class AbpLoggerExtensions
             var json = JsonSerializer.Serialize(value);
             if (json.Length > MaxDataValueLength)
             {
-                return json.Substring(0, MaxDataValueLength) + "...(truncated)";
+                return json.Substring(0, MaxDataValueLength - TruncationSuffix.Length) + TruncationSuffix;
             }
 
             return json;

framework/test/Volo.Abp.Core.Tests/Microsoft/Extensions/Logging/AbpLoggerExtensions_Tests.cs

@@ -145,7 +145,8 @@ public class AbpLoggerExtensions_Tests
         logger.LogException(exception);
 
         logger.LastLoggedMessage.ShouldNotBeNull();
-        logger.LastLoggedMessage.ShouldContain("BadObject = ");
+        logger.LastLoggedMessage.ShouldContain("BadObject = SelfRef:Loop");
+        logger.LastLoggedMessage.ShouldNotContain("\"Name\"");
     }
 
     [Fact]
@@ -172,6 +173,7 @@ public class AbpLoggerExtensions_Tests
     private class SelfReferencingObject
     {
         public string Name { get; set; } = default!;
+        public override string ToString() => $"SelfRef:{Name}";
         public SelfReferencingObject? Self { get; set; }
     }