Fixed LoggerMessageGenerator message escaping. (#123787)

John-Leitch · cincuranet · Copilot · web-flow · commit 8acd159546de · 2026-02-01T16:57:06.000-08:00
This PR addresses bug #123786 by escaping all non-printable characters (`< 0x20`) in the emitted message. `\r` and `\n` are emitted using the same escape sequence, while other non-printable characters are emitted as hex escape sequences e.g. `\x00`. Escaping of `\` is also addressed. Finally, an additional test was added to cover these behaviors. --------- Co-authored-by: Jiri Cincura ↹ <jiri@cincura.net> Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> Co-authored-by: Tarek Mahmoud Sayed <10833894+tarekgh@users.noreply.github.com> Co-authored-by: Tarek Mahmoud Sayed <tarekms@microsoft.com>
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/LoggerMessageGenerator.Emitter.cs b/src/libraries/Microsoft.Extensions.Logging.Abstractions/gen/LoggerMessageGenerator.Emitter.cs
@@ -7,6 +7,7 @@
 using System.Text;
 using System.Threading;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
 
 namespace Microsoft.Extensions.Logging.Generators
 {
@@ -181,7 +182,7 @@ private void GenStruct(LoggerMethod lm, string nestedIndentation)
                 string formatMethodEnd = formatMethodBegin.Length > 0 ? ")" : "";
 
                 _builder.Append($@"
-                {nestedIndentation}return {formatMethodBegin}$""{ConvertEndOfLineAndQuotationCharactersToEscapeForm(lm.Message)}""{formatMethodEnd};
+                {nestedIndentation}return {formatMethodBegin}${SymbolDisplay.FormatLiteral(lm.Message, quote: true)}{formatMethodEnd};
             {nestedIndentation}}}
 ");
                 _builder.Append($@"
@@ -280,7 +281,7 @@ private void GenCases(LoggerMethod lm, string nestedIndentation)
                     _builder.AppendLine($"                    {nestedIndentation}{index++} => new global::System.Collections.Generic.KeyValuePair<string, object?>(\"{name}\", this.{NormalizeSpecialSymbol(p.CodeName)}),");
                 }
 
-                _builder.AppendLine($"                    {nestedIndentation}{index++} => new global::System.Collections.Generic.KeyValuePair<string, object?>(\"{{OriginalFormat}}\", \"{ConvertEndOfLineAndQuotationCharactersToEscapeForm(lm.Message)}\"),");
+                _builder.AppendLine($"                    {nestedIndentation}{index++} => new global::System.Collections.Generic.KeyValuePair<string, object?>(\"{{OriginalFormat}}\", {SymbolDisplay.FormatLiteral(lm.Message, quote: true)}),");
             }
 
             private void GenCallbackArguments(LoggerMethod lm)
@@ -406,7 +407,7 @@ private void GenLogMethod(LoggerMethod lm, string nestedIndentation)
 
                     GenDefineTypes(lm, brackets: true);
 
-                    _builder.Append(@$"({level}, new global::Microsoft.Extensions.Logging.EventId({lm.EventId}, {eventName}), ""{ConvertEndOfLineAndQuotationCharactersToEscapeForm(lm.Message)}"", new global::Microsoft.Extensions.Logging.LogDefineOptions() {{ SkipEnabledCheck = true }}); 
+                    _builder.Append(@$"({level}, new global::Microsoft.Extensions.Logging.EventId({lm.EventId}, {eventName}), {SymbolDisplay.FormatLiteral(lm.Message, quote: true)}, new global::Microsoft.Extensions.Logging.LogDefineOptions() {{ SkipEnabledCheck = true }});
 ");
                 }
 
@@ -576,55 +577,6 @@ public static string Enumerate(global::System.Collections.IEnumerable? enumerabl
             }
         }
 
-        private static string ConvertEndOfLineAndQuotationCharactersToEscapeForm(string s)
-        {
-            int index = 0;
-            while (index < s.Length)
-            {
-                if (s[index] is '\n' or '\r' or '"')
-                {
-                    break;
-                }
-                index++;
-            }
-
-            if (index >= s.Length)
-            {
-                return s;
-            }
-
-            StringBuilder sb = new StringBuilder(s.Length);
-            sb.Append(s, 0, index);
-
-            while (index < s.Length)
-            {
-                switch (s[index])
-                {
-                    case '\n':
-                        sb.Append('\\');
-                        sb.Append('n');
-                        break;
-
-                    case '\r':
-                        sb.Append('\\');
-                        sb.Append('r');
-                        break;
-
-                    case '"':
-                        sb.Append('\\');
-                        sb.Append('"');
-                        break;
-
-                    default:
-                        sb.Append(s[index]);
-                        break;
-                }
-
-                index++;
-            }
-
-            return sb.ToString();
-        }
         /// <summary>
         /// Checks if variableOrTemplateName contains a special symbol ('@') as starting char
         /// </summary>
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerFromPrimaryConstructor.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerFromPrimaryConstructor.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M0Callback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         public partial void M0()
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerFromPrimaryConstructorWithParameterUsedInMethod.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerFromPrimaryConstructorWithParameterUsedInMethod.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M0Callback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         public partial void M0()
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerInFieldAndFromPrimaryConstructor.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithLoggerInFieldAndFromPrimaryConstructor.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M0Callback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         public partial void M0()
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithMultipleClassesStableOrder.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithMultipleClassesStableOrder.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __LogACallback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(1, nameof(LogA)), "Message from ClassA", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(1, nameof(LogA)), "Message from ClassA", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         static partial void LogA(global::Microsoft.Extensions.Logging.ILogger logger)
@@ -25,7 +25,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __LogBCallback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Information, new global::Microsoft.Extensions.Logging.EventId(2, nameof(LogB)), "Message from ClassB", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Information, new global::Microsoft.Extensions.Logging.EventId(2, nameof(LogB)), "Message from ClassB", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         static partial void LogB(global::Microsoft.Extensions.Logging.ILogger logger)
@@ -43,7 +43,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __LogCCallback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Warning, new global::Microsoft.Extensions.Logging.EventId(3, nameof(LogC)), "Message from ClassC", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Warning, new global::Microsoft.Extensions.Logging.EventId(3, nameof(LogC)), "Message from ClassC", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         static partial void LogC(global::Microsoft.Extensions.Logging.ILogger logger)
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithNestedClass.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithNestedClass.generated.txt
@@ -17,7 +17,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses.NestedNamesp
                         {
                             [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
                             private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M9Callback =
-                                global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(9, nameof(M9)), "M9", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+                                global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(9, nameof(M9)), "M9", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
                             [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
                             public static partial void M9(global::Microsoft.Extensions.Logging.ILogger logger)
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithNestedClassWithGenericTypesWithAttributes.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithNestedClassWithGenericTypesWithAttributes.generated.txt
@@ -9,7 +9,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
         {
             [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
             private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, A, B, C, global::System.Exception?> __M0Callback =
-                global::Microsoft.Extensions.Logging.LoggerMessage.Define<A, B, C>(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(42, nameof(M0)), "a = {a}; b = {b}; c = {c}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+                global::Microsoft.Extensions.Logging.LoggerMessage.Define<A, B, C>(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(42, nameof(M0)), "a = {a}; b = {b}; c = {c}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
             [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
             public static partial void M0(global::Microsoft.Extensions.Logging.ILogger logger, A a, B b, C c)
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithSkipEnabledCheck.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithSkipEnabledCheck.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M0Callback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Information, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "Message: When using SkipEnabledCheck, the generated code skips logger.IsEnabled(logLevel) check before calling log. To be used when consumer has already guarded logger method in an IsEnabled check.", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Information, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "Message: When using SkipEnabledCheck, the generated code skips logger.IsEnabled(logLevel) check before calling log. To be used when consumer has already guarded logger method in an IsEnabled check.", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         public static partial void M0(global::Microsoft.Extensions.Logging.ILogger logger)
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithTwoParams.generated.txt b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/Baselines/TestWithTwoParams.generated.txt
@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses
     {
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Int32, global::System.Collections.Generic.IEnumerable<global::System.Int32>, global::System.Exception?> __M0Callback =
-            global::Microsoft.Extensions.Logging.LoggerMessage.Define<global::System.Int32, global::System.Collections.Generic.IEnumerable<global::System.Int32>>(global::Microsoft.Extensions.Logging.LogLevel.Error, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0 {a1} {a2}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true }); 
+            global::Microsoft.Extensions.Logging.LoggerMessage.Define<global::System.Int32, global::System.Collections.Generic.IEnumerable<global::System.Int32>>(global::Microsoft.Extensions.Logging.LogLevel.Error, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0 {a1} {a2}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });
 
         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]
         public static partial void M0(global::Microsoft.Extensions.Logging.ILogger logger, global::System.Int32 a1, global::System.Collections.Generic.IEnumerable<global::System.Int32> a2)
diff --git a/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/LoggerMessageGeneratorEmitterTests.cs b/src/libraries/Microsoft.Extensions.Logging.Abstractions/tests/Microsoft.Extensions.Logging.Generators.Tests/LoggerMessageGeneratorEmitterTests.cs
@@ -277,6 +277,58 @@ public void GenericTypeParameterAttributesAreRetained()
             Assert.NotNull(type.GenericTypeParameters[1].GetCustomAttribute<TestClasses.BarAttribute>());
         }
 
+        [Theory]
+        [InlineData(@"Foo \\ bar: {foo}", null)]
+        [InlineData(@"Foo \\\\ bar: {foo}", null)]
+        [InlineData(@"Foo \"" bar: {foo}", null)]
+        [InlineData(@"Foo \x22 bar: {foo}", @"Foo \"" bar: {foo}")]
+        [InlineData(@"Foo \u0022 bar: {foo}", @"Foo \"" bar: {foo}")]
+        [InlineData(@"Foo \r bar: {foo}", null)]
+        [InlineData(@"Foo \x0d bar: {foo}", @"Foo \r bar: {foo}")]
+        [InlineData(@"Foo \u000d bar: {foo}", @"Foo \r bar: {foo}")]
+        [InlineData(@"Foo \n bar: {foo}", null)]
+        [InlineData(@"Foo \x0a bar: {foo}", @"Foo \n bar: {foo}")]
+        [InlineData(@"Foo \u000a bar: {foo}", @"Foo \n bar: {foo}")]
+        [InlineData(@"Foo \0 bar: {foo}", null)]
+        [InlineData(@"Foo \x00 bar: {foo}", @"Foo \0 bar: {foo}")]
+        [InlineData(@"Foo \u0000 bar: {foo}", @"Foo \0 bar: {foo}")]
+        [InlineData(@"Foo \x1f bar: {foo}", @"Foo \u001f bar: {foo}")]
+        [InlineData(@"Foo \u001f bar: {foo}", null)]
+        public async Task EmittedMessageIsWellFormed(string message, string? expectedMessage)
+        {
+            var code =
+                $$"""
+                namespace Test
+                {
+                    using Microsoft.Extensions.Logging;
+
+                    partial class C
+                    {
+                        [LoggerMessage(EventId = 5230, Level = LogLevel.Information, Message = "{{message}}")]
+                        static partial void Test(ILogger logger, string foo);
+                    }
+                }
+                """;
+
+            var (diagnostics, generatedSources) = await RoslynTestUtils
+                .RunGenerator(
+                    new LoggerMessageGenerator(),
+                    new[] { typeof(ILogger).Assembly, typeof(LoggerMessageAttribute).Assembly },
+                    new[] { code },
+                    includeBaseReferences: true)
+                .ConfigureAwait(false);
+
+            Assert.Empty(diagnostics);
+            Assert.Single(generatedSources);
+
+            var generatedSource = generatedSources[0];
+            var src = generatedSource.SourceText.ToString();
+            Assert.Contains($"\"{expectedMessage ?? message}\"", src);
+
+            var generatedSourceDiagnostics = generatedSource.SyntaxTree.GetDiagnostics();
+            Assert.Empty(generatedSourceDiagnostics);
+        }
+
         private async Task VerifyAgainstBaselineUsingFile(string filename, string testSourceCode)
         {
             string baseline = LineEndingsHelper.Normalize(File.ReadAllText(Path.Combine("Baselines", filename)));

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses`
`7`	`7`	`{`
`8`	`8`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`9`	`9`	`private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M0Callback =`
`10`		`- global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
	`10`	`+ global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(0, nameof(M0)), "M0", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
`11`	`11`
`12`	`12`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`13`	`13`	`public partial void M0()`
Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses.NestedNamesp`
`17`	`17`	`{`
`18`	`18`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`19`	`19`	`private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, global::System.Exception?> __M9Callback =`
`20`		`- global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(9, nameof(M9)), "M9", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
	`20`	`+ global::Microsoft.Extensions.Logging.LoggerMessage.Define(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(9, nameof(M9)), "M9", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
`21`	`21`
`22`	`22`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`23`	`23`	`public static partial void M9(global::Microsoft.Extensions.Logging.ILogger logger)`
Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@ namespace Microsoft.Extensions.Logging.Generators.Tests.TestClasses`
`9`	`9`	`{`
`10`	`10`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`11`	`11`	`private static readonly global::System.Action<global::Microsoft.Extensions.Logging.ILogger, A, B, C, global::System.Exception?> __M0Callback =`
`12`		`- global::Microsoft.Extensions.Logging.LoggerMessage.Define<A, B, C>(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(42, nameof(M0)), "a = {a}; b = {b}; c = {c}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
	`12`	`+ global::Microsoft.Extensions.Logging.LoggerMessage.Define<A, B, C>(global::Microsoft.Extensions.Logging.LogLevel.Debug, new global::Microsoft.Extensions.Logging.EventId(42, nameof(M0)), "a = {a}; b = {b}; c = {c}", new global::Microsoft.Extensions.Logging.LogDefineOptions() { SkipEnabledCheck = true });`
`13`	`13`
`14`	`14`	`[global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Extensions.Logging.Generators", "%VERSION%")]`
`15`	`15`	`public static partial void M0(global::Microsoft.Extensions.Logging.ILogger logger, A a, B b, C c)`