Improve LevelTokenRenderer handling and add tests

vonhoff · vonhoff · commit 1a8c356187b7 · 2025-11-09T15:13:07.000+01:00
Enhanced LevelTokenRenderer to gracefully handle invalid log level indices and expanded test coverage for various level formatting scenarios. Also cleaned up unused usings and removed redundant tests in TokenRendererTests.
diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
@@ -1 +1,2 @@
 github: vonhoff
+ko-fi: vonhoff
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
@@ -1,6 +1,6 @@
 <!-- Summarize your changes in the title -->
 
-**Motivation and Context**
+**Context**
 
 <!-- Why is this change needed? Link any relevant issues. -->
 
diff --git a/Serilog.Sinks.RichTextBox.WinForms.Colored.Test/Integration/JsonFormattingTests.cs b/Serilog.Sinks.RichTextBox.WinForms.Colored.Test/Integration/JsonFormattingTests.cs
@@ -1,7 +1,5 @@
-using System;
 using Serilog.Events;
 using Serilog.Sinks.RichTextBoxForms;
-using Serilog.Sinks.RichTextBoxForms.Themes;
 using Xunit;
 
 namespace Serilog.Tests.Integration
@@ -260,7 +258,7 @@ public void ScalarValue_IFormattableButNotNumericValueType()
             var enumValue = System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance;
             var prop = new LogEventProperty("EnumProp", new ScalarValue(enumValue));
             var logEvent = new LogEvent(DateTimeOffset.Now, LogEventLevel.Information, null, _parser.Parse("{EnumProp:j}"), new[] { prop });
-            
+
             var result = RenderAndGetText(logEvent, "{Message:j}");
             Assert.NotNull(result);
             Assert.NotEmpty(result);
@@ -272,7 +270,7 @@ public void ScalarValue_NonFormattableObject()
             var plainObject = new object();
             var prop = new LogEventProperty("ObjectProp", new ScalarValue(plainObject));
             var logEvent = new LogEvent(DateTimeOffset.Now, LogEventLevel.Information, null, _parser.Parse("{ObjectProp:j}"), new[] { prop });
-            
+
             var result = RenderAndGetText(logEvent, "{Message:j}");
             Assert.NotNull(result);
             Assert.NotEmpty(result);
diff --git a/Serilog.Sinks.RichTextBox.WinForms.Colored.Test/Integration/TokenRendererTests.cs b/Serilog.Sinks.RichTextBox.WinForms.Colored.Test/Integration/TokenRendererTests.cs
@@ -1,10 +1,6 @@
 using Serilog.Events;
 using Serilog.Parsing;
 using Serilog.Sinks.RichTextBoxForms.Rendering;
-using Serilog.Sinks.RichTextBoxForms.Themes;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xunit;
 
 namespace Serilog.Tests.Integration
@@ -37,37 +33,9 @@ public void ExceptionTokenRenderer_RendersExceptionWithStackFrames()
             var result = _richTextBox.Text;
             Assert.Contains("InvalidOperationException", result);
             Assert.Contains("Test exception", result);
-            
-            var lines = result.Split(new[] { '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries);
-            Assert.True(lines.Length > 1, $"Exception should have multiple lines including stack trace. Got: {lines.Length} lines. Text: {result}");
-        }
-
-        [Fact]
-        public void ExceptionTokenRenderer_RendersMultipleLines()
-        {
-            Exception? exception = null;
-            try
-            {
-                throw new InvalidOperationException("Test exception");
-            }
-            catch (Exception ex)
-            {
-                exception = ex;
-            }
-
-            var logEvent = new LogEvent(
-                DateTimeOffset.Now,
-                LogEventLevel.Error,
-                exception,
-                _parser.Parse("Error occurred"),
-                Array.Empty<LogEventProperty>());
-
-            var renderer = new ExceptionTokenRenderer(_defaultTheme);
-            renderer.Render(logEvent, _canvas);
 
-            var result = _richTextBox.Text;
             var lines = result.Split(new[] { '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries);
-            Assert.True(lines.Length > 1, $"Exception should have multiple lines. Got: {lines.Length} lines. Text: {result}");
+            Assert.True(lines.Length > 1, $"Exception should have multiple lines including stack trace. Got: {lines.Length} lines. Text: {result}");
         }
 
         [Fact]
@@ -107,26 +75,6 @@ public void EventPropertyTokenRenderer_RendersNonStringScalarValue()
             Assert.Contains("42", result);
         }
 
-        [Fact]
-        public void EventPropertyTokenRenderer_RendersBooleanValue()
-        {
-            var template = _parser.Parse("IsValid: {IsValid}");
-            var propertyToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "IsValid");
-            var renderer = new EventPropertyTokenRenderer(_defaultTheme, propertyToken, null);
-
-            var logEvent = new LogEvent(
-                DateTimeOffset.Now,
-                LogEventLevel.Information,
-                null,
-                template,
-                new[] { new LogEventProperty("IsValid", new ScalarValue(true)) });
-
-            renderer.Render(logEvent, _canvas);
-
-            var result = _richTextBox.Text;
-            Assert.Contains("True", result);
-        }
-
         [Fact]
         public void EventPropertyTokenRenderer_RendersStructureValue()
         {
@@ -254,6 +202,228 @@ public void EventPropertyTokenRenderer_RendersStringValue()
             var result = _richTextBox.Text;
             Assert.Contains("Hello World", result);
         }
+
+        [Fact]
+        public void LevelTokenRenderer_WithLowercaseFormat_RendersCorrectly()
+        {
+            var template = _parser.Parse("Level: {Level:w3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("inf", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithTitleCaseFormat_RendersCorrectly()
+        {
+            var template = _parser.Parse("Level: {Level:t3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Warning,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("Wrn", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithUppercaseFormat_RendersCorrectly()
+        {
+            var template = _parser.Parse("Level: {Level:u3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Error,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("ERR", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithThreeDigitWidth_RendersCorrectly()
+        {
+            var template = _parser.Parse("Level: {Level:u10}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("INFORMATIO", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithWidthLessThanOne_ReturnsEmpty()
+        {
+            var template = _parser.Parse("Level: {Level:u0}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Empty(result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithWidthGreaterThanFour_TruncatesAndFormats()
+        {
+            var template = _parser.Parse("Level: {Level:u5}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("INFOR", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithInvalidFormatSpecifier_UsesTextFormatter()
+        {
+            var template = _parser.Parse("Level: {Level:x3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("Information", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithNonStandardFormatLength_UsesTextFormatter()
+        {
+            var template = _parser.Parse("Level: {Level:u}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Information,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("INFORMATION", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithInvalidLevelIndex_HandlesGracefully()
+        {
+            var template = _parser.Parse("Level: {Level:u3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var invalidLevel = (LogEventLevel)999;
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                invalidLevel,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("999", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithNegativeLevelIndex_HandlesGracefully()
+        {
+            var template = _parser.Parse("Level: {Level:u3}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var invalidLevel = (LogEventLevel)(-1);
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                invalidLevel,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("-1", result);
+        }
+
+        [Fact]
+        public void LevelTokenRenderer_WithWidthGreaterThanStringLength_DoesNotTruncate()
+        {
+            var template = _parser.Parse("Level: {Level:u20}");
+            var levelToken = template.Tokens.OfType<PropertyToken>().Single(t => t.PropertyName == "Level");
+            var renderer = new LevelTokenRenderer(_defaultTheme, levelToken);
+
+            var logEvent = new LogEvent(
+                DateTimeOffset.Now,
+                LogEventLevel.Verbose,
+                null,
+                _parser.Parse("Test"),
+                Array.Empty<LogEventProperty>());
+
+            renderer.Render(logEvent, _canvas);
+
+            var result = _richTextBox.Text;
+            Assert.Contains("VERBOSE", result);
+        }
     }
 }
 
diff --git a/Serilog.Sinks.RichTextBox.WinForms.Colored/Sinks/RichTextBoxForms/Rendering/LevelTokenRenderer.cs b/Serilog.Sinks.RichTextBox.WinForms.Colored/Sinks/RichTextBoxForms/Rendering/LevelTokenRenderer.cs
@@ -82,6 +82,14 @@ public LevelTokenRenderer(Theme theme, PropertyToken levelToken)
         public void Render(LogEvent logEvent, IRtfCanvas canvas)
         {
             var levelIndex = (int)logEvent.Level;
+            if (levelIndex < 0 || levelIndex >= _monikers.Length)
+            {
+                var format = string.Empty;
+                var fallbackMoniker = TextFormatter.Format(logEvent.Level.ToString(), format);
+                _theme.Render(canvas, StyleToken.Text, fallbackMoniker);
+                return;
+            }
+
             var moniker = _monikers[levelIndex];
             var levelStyle = LevelStyles[levelIndex];
             _theme.Render(canvas, levelStyle, moniker);
@@ -119,11 +127,6 @@ private static string GetLevelMoniker(LogEventLevel value, string format = "")
             }
 
             var index = (int)value;
-            if (index is < 0 or > (int)LogEventLevel.Fatal)
-            {
-                return TextFormatter.Format(value.ToString(), format);
-            }
-
             return format[0] switch
             {
                 'w' => LowercaseLevelMap[index][width - 1],
