[release/8.0-preview7] Share SourceWriter between JSON & config binding generators (#89196)

* Share SourceWriter between JSON & config binding generators

* Fix failing test, clean up impl, and address feedback

---------
Co-authored-by: NLayomi Akinrinade <laakinri@microsoft.com>
Co-authored-by: NEric StJohn <ericstj@microsoft.com>

src/libraries/System.Text.Json/gen/Helpers/SourceWriter.cs → src/libraries/Common/src/SourceGenerators/SourceWriter.cs

 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.CodeAnalysis.Text;
+using System;
+using System.Text;
 using System.Diagnostics;
+using Microsoft.CodeAnalysis.Text;
 
-namespace System.Text.Json.SourceGeneration
+namespace SourceGenerators
 {
     internal sealed class SourceWriter
     {
+        private const char IndentationChar = ' ';
+        private const int CharsPerIndentation = 4;
+
         private readonly StringBuilder _sb = new();
         private int _indentation;
 
-        public SourceWriter()
-        {
-            IndentationChar = ' ';
-            CharsPerIndentation = 4;
-        }
-
-        public SourceWriter(char indentationChar, int charsPerIndentation)
-        {
-            if (!char.IsWhiteSpace(indentationChar))
-            {
-                throw new ArgumentOutOfRangeException(nameof(indentationChar));
-            }
-
-            if (charsPerIndentation < 1)
-            {
-                throw new ArgumentOutOfRangeException(nameof(charsPerIndentation));
-            }
-
-            IndentationChar = indentationChar;
-            CharsPerIndentation = charsPerIndentation;
-        }
-
-        public char IndentationChar { get; }
-        public int CharsPerIndentation { get; }
-
-        public int Length => _sb.Length;
         public int Indentation
         {
             get => _indentation;
@@ -88,6 +67,12 @@ public SourceText ToSourceText()
             return SourceText.From(_sb.ToString(), Encoding.UTF8);
         }
 
+        public void Reset()
+        {
+            _sb.Clear();
+            _indentation = 0;
+        }
+
         private void AddIndentation()
             => _sb.Append(IndentationChar, CharsPerIndentation * _indentation);
 

src/libraries/Common/tests/Common.Tests.csproj

@@ -18,6 +18,8 @@
              Link="Common\Interop\Linux\Interop.ProcFsStat.TryReadStatusFile.cs" />
     <Compile Include="$(CommonPath)Interop\Linux\os-release\Interop.OSReleaseFile.cs"
              Link="Common\Interop\Linux\os-release\Interop.OSReleaseFile.cs" />
+    <Compile Include="$(CommonPath)SourceGenerators\SourceWriter.cs"
+             Link="Common\SourceGenerators\SourceWriter.cs" />
     <Compile Include="$(CommonPath)System\CharArrayHelpers.cs"
              Link="Common\System\CharArrayHelpers.cs" />
     <Compile Include="$(CommonPath)System\StringExtensions.cs"
@@ -81,6 +83,7 @@
     <Compile Include="Tests\Interop\cgroupsTests.cs" />
     <Compile Include="Tests\Interop\procfsTests.cs" />
     <Compile Include="Tests\Interop\OSReleaseTests.cs" />
+    <Compile Include="Tests\SourceGenerators\SourceWriterTests.cs" />
     <Compile Include="Tests\System\IO\PathInternal.Tests.cs" />
     <Compile Include="Tests\System\IO\StringParserTests.cs" />
     <Compile Include="Tests\System\Net\HttpDateParserTests.cs" />
@@ -155,6 +158,9 @@
     <Folder Include="System\Net\Sockets\" />
     <Folder Include="System\Net\VirtualNetwork\" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="$(MicrosoftCodeAnalysisVersion_LatestVS)" PrivateAssets="all" />
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(CommonTestPath)StreamConformanceTests\StreamConformanceTests.csproj" />
   </ItemGroup>

src/libraries/Common/tests/Tests/SourceGenerators/SourceWriterTests.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using SourceGenerators;
+using Xunit;
+
+namespace Common.Tests
+{
+    public sealed class SourceWriterTests
+    {
+        [Fact]
+        public void CanHandleVariousLineEndings()
+        {
+            string testTemplate = "public static void Main(){0}{{{1}\tConsole.WriteLine(\"Hello, world\");{2}}}";
+            SourceWriter writer = new();
+
+            CheckCanWrite(string.Format(testTemplate, "\n", "\n", "\n"));
+            CheckCanWrite(string.Format(testTemplate, "\r\n", "\r\n", "\r\n"));
+            CheckCanWrite(string.Format(testTemplate, "\n", "\r\n", "\n"));
+
+            // Regression test for https://github.com/dotnet/runtime/issues/88918.
+            CheckCanWrite("    global::Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.AddOptions(services);\r\n    global::Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddSingleton<global::Microsoft.Extensions.Options.IOptionsChangeTokenSource<TOptions>>(services, new global::Microsoft.Extensions.Options.ConfigurationChangeTokenSource<TOptions>(name, configuration));\r\n    return global::Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddSingleton<global::Microsoft.Extensions.Options.IConfigureOptions<TOptions>>(services, new global::Microsoft.Extensions.Options.ConfigureNamedOptions<TOptions>(name, obj => global::Microsoft.Extensions.Configuration.Binder.SourceGeneration.CoreBindingHelper.BindCoreUntyped(configuration, obj, typeof(TOptions), configureOptions)));\r\n}");
+
+            void CheckCanWrite(string source)
+            {
+                // No exception expected.
+                writer.WriteLine(source);
+                writer.Reset();
+            }
+        }
+    }
+}

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -5,6 +5,7 @@
 using System.Diagnostics;
 using System.Text.RegularExpressions;
 using Microsoft.CodeAnalysis;
+using SourceGenerators;
 
 namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
 {
@@ -36,17 +37,17 @@ public void Emit()
                     return;
                 }
 
-                _writer.WriteBlock("""
+                _writer.WriteLine("""
                     // <auto-generated/>
                     #nullable enable
                     #pragma warning disable CS0612, CS0618 // Suppress warnings about [Obsolete] member usage in generated code.
                     """);
-                _writer.WriteBlankLine();
+                _writer.WriteLine();
 
                 _useFullyQualifiedNames = true;
-                EmitBinder_ConfigurationBinder();
+                EmitBinder_Extensions_IConfiguration();
                 EmitBinder_Extensions_OptionsBuilder();
-                EmitBinder_Extensions_ServiceCollection();
+                EmitBinder_Extensions_IServiceCollection();
 
                 _useFullyQualifiedNames = false;
                 Emit_CoreBindingHelper();
@@ -131,14 +132,16 @@ void EmitObjectInit(string objExpression, InitializationKind initKind)
 
                 if (!checkForNullSectionValue)
                 {
-                    writeOnSuccess?.Invoke(parsedValueExpr);
+                    InvokeWriteOnSuccess();
                 }
                 else
                 {
-                    _writer.WriteBlockStart($"if ({sectionValueExpr} is string {nonNull_StringValue_Identifier})");
-                    writeOnSuccess?.Invoke(parsedValueExpr);
-                    _writer.WriteBlockEnd();
+                    EmitStartBlock($"if ({sectionValueExpr} is string {nonNull_StringValue_Identifier})");
+                    InvokeWriteOnSuccess();
+                    EmitEndBlock();
                 }
+
+                void InvokeWriteOnSuccess() => writeOnSuccess?.Invoke(parsedValueExpr);
             }
 
             private bool EmitObjectInit(TypeSpec type, string memberAccessExpr, InitializationKind initKind, string configArgExpr)
@@ -222,7 +225,7 @@ private void EmitCastToIConfigurationSection()
                     exceptionTypeDisplayString = nameof(InvalidOperationException);
                 }
 
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     if ({{Identifier.configuration}} is not {{sectionTypeDisplayString}} {{Identifier.section}})
                     {
                         throw new {{exceptionTypeDisplayString}}();
@@ -235,13 +238,13 @@ private void EmitIConfigurationHasValueOrChildrenCheck(bool voidReturn)
                 string returnPostfix = voidReturn ? string.Empty : " null";
                 string methodDisplayString = GetHelperMethodDisplayString(Identifier.HasValueOrChildren);
 
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     if (!{{methodDisplayString}}({{Identifier.configuration}}))
                     {
                         return{{returnPostfix}};
                     }
                     """);
-                _writer.WriteBlankLine();
+                _writer.WriteLine();
             }
         }
     }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Helpers/Emitter/ConfigurationBinder.cs

@@ -14,7 +14,7 @@ private sealed partial class Emitter
         {
             private bool ShouldEmitMethods(MethodsToGen_ConfigurationBinder methods) => (_sourceGenSpec.MethodsToGen_ConfigurationBinder & methods) != 0;
 
-            private void EmitBinder_ConfigurationBinder()
+            private void EmitBinder_Extensions_IConfiguration()
             {
                 Debug.Assert(_sourceGenSpec.TypesForGen_ConfigurationBinder_BindMethods.Count <= 3 &&
                     !_sourceGenSpec.TypesForGen_ConfigurationBinder_BindMethods.Keys.Any(overload => (overload & MethodsToGen_ConfigurationBinder.Bind) is 0));
@@ -25,13 +25,13 @@ private void EmitBinder_ConfigurationBinder()
                 }
 
                 _emitBlankLineBeforeNextStatement = false;
-                EmitRootBindingClassBlockStart(Identifier.GeneratedConfigurationBinder);
+                EmitRootBindingClassStartBlock(Identifier.GeneratedConfigurationBinder);
 
                 EmitGetMethods();
                 EmitGetValueMethods();
                 EmitBindMethods_ConfigurationBinder();
 
-                _writer.WriteBlockEnd();
+                EmitEndBlock();
                 _emitBlankLineBeforeNextStatement = true;
             }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Helpers/Emitter/Helpers.cs

@@ -129,11 +129,43 @@ private static class Identifier
                 ShouldEmitMethods(MethodsToGen_Extensions_OptionsBuilder.Any) ||
                 ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection.Any);
 
+            /// <summary>
+            /// Starts a block of source code.
+            /// </summary>
+            /// <param name="source">Source to write after the open brace.</param>
+            public void EmitStartBlock(string? source = null)
+            {
+                if (source is not null)
+                {
+                    _writer.WriteLine(source);
+                }
+
+                _writer.WriteLine("{");
+                _writer.Indentation++;
+            }
+
+            /// <summary>
+            /// Ends a block of source code.
+            /// </summary>
+            /// <param name="source">Source to write before the close brace.</param>
+            /// <param name="endBraceTrailingSource">Trailing source after the end brace, e.g. ";" to end an init statement.</param>
+            public void EmitEndBlock(string? source = null, string? endBraceTrailingSource = null)
+            {
+                if (source is not null)
+                {
+                    _writer.WriteLine(source);
+                }
+
+                string endBlockSource = endBraceTrailingSource is null ? "}" : $"}}{endBraceTrailingSource}";
+                _writer.Indentation--;
+                _writer.WriteLine(endBlockSource);
+            }
+
             private void EmitBlankLineIfRequired()
             {
                 if (_emitBlankLineBeforeNextStatement)
                 {
-                    _writer.WriteBlankLine();
+                    _writer.WriteLine();
                 }
 
                 _emitBlankLineBeforeNextStatement = true;
@@ -153,14 +185,14 @@ private void EmitCheckForNullArgument_WithBlankLine(string paramName)
                     ? "global::System.ArgumentNullException"
                     : "ArgumentNullException";
 
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     if ({{paramName}} is null)
                     {
                         throw new {{exceptionTypeDisplayString}}(nameof({{paramName}}));
                     }
                     """);
 
-                _writer.WriteBlankLine();
+                _writer.WriteLine();
             }
 
             private bool EmitInitException(TypeSpec type)
@@ -176,14 +208,13 @@ private bool EmitInitException(TypeSpec type)
                 return false;
             }
 
-            private void EmitRootBindingClassBlockStart(string className)
+            private void EmitRootBindingClassStartBlock(string className)
             {
                 EmitBlankLineIfRequired();
-                _writer.WriteBlock($$"""
+                EmitStartBlock($$"""
                     /// <summary>Generated helper providing an AOT and linking compatible implementation for configuration binding.</summary>
                     {{GetGeneratedCodeAttributeSrc()}}
                     internal static class {{className}}
-                    {
                     """);
 
                 _emitBlankLineBeforeNextStatement = false;

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Helpers/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -16,12 +16,12 @@ private void EmitBinder_Extensions_OptionsBuilder()
                     return;
                 }
 
-                EmitRootBindingClassBlockStart(Identifier.GeneratedOptionsBuilderBinder);
+                EmitRootBindingClassStartBlock(Identifier.GeneratedOptionsBuilderBinder);
 
                 EmitBindMethods_Extensions_OptionsBuilder();
                 EmitBindConfigurationMethod();
 
-                _writer.WriteBlockEnd();
+                EmitEndBlock();
             }
 
             private void EmitBindMethods_Extensions_OptionsBuilder()
@@ -36,24 +36,24 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
 
                 if (ShouldEmitMethods(MethodsToGen_Extensions_OptionsBuilder.Bind_T))
                 {
-                    EmitMethodBlockStart("Bind", paramList, documentation);
+                    EmitMethodStartBlock("Bind", paramList, documentation);
                     _writer.WriteLine($"return global::{Identifier.GeneratedOptionsBuilderBinder}.Bind({Identifier.optionsBuilder}, {Identifier.configuration}, {Identifier.configureOptions}: null);");
-                    _writer.WriteBlockEnd();
+                    EmitEndBlock();
                 }
 
-                EmitMethodBlockStart(
+                EmitMethodStartBlock(
                     "Bind",
                     paramList + $", {FullyQualifiedDisplayString.ActionOfBinderOptions}? {Identifier.configureOptions}",
                     documentation);
 
                 EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
 
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     global::{{Identifier.GeneratedServiceCollectionBinder}}.{{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.configuration}}, {{Identifier.configureOptions}});
                     return {{Identifier.optionsBuilder}};
                     """);
 
-                _writer.WriteBlockEnd();
+                EmitEndBlock();
             }
 
             private void EmitBindConfigurationMethod()
@@ -66,37 +66,37 @@ private void EmitBindConfigurationMethod()
                 const string documentation = $@"/// <summary>Registers the dependency injection container to bind <typeparamref name=""TOptions""/> against the <see cref=""{FullyQualifiedDisplayString.IConfiguration}""/> obtained from the DI service provider.</summary>";
                 string paramList = $"string {Identifier.configSectionPath}, {FullyQualifiedDisplayString.ActionOfBinderOptions}? {Identifier.configureOptions} = null";
 
-                EmitMethodBlockStart("BindConfiguration", paramList, documentation);
+                EmitMethodStartBlock("BindConfiguration", paramList, documentation);
 
                 EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
                 EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
 
-                _writer.WriteBlockStart($"{Identifier.optionsBuilder}.{Identifier.Configure}<{FullyQualifiedDisplayString.IConfiguration}>(({Identifier.obj}, {Identifier.configuration}) =>");
+                EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{FullyQualifiedDisplayString.IConfiguration}>(({Identifier.obj}, {Identifier.configuration}) =>");
 
-                _writer.WriteBlock($$"""
-                {{FullyQualifiedDisplayString.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, global::System.StringComparison.OrdinalIgnoreCase) ? {{Identifier.configuration}} : {{Identifier.configuration}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
-                {{FullyQualifiedDisplayString.CoreBindingHelper}}.{{nameof(MethodsToGen_CoreBindingHelper.BindCoreUntyped)}}({{Identifier.section}}, {{Identifier.obj}}, typeof({{Identifier.TOptions}}), {{Identifier.configureOptions}});
-            """);
+                _writer.WriteLine($$"""
+                    {{FullyQualifiedDisplayString.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, global::System.StringComparison.OrdinalIgnoreCase) ? {{Identifier.configuration}} : {{Identifier.configuration}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
+                    {{FullyQualifiedDisplayString.CoreBindingHelper}}.{{nameof(MethodsToGen_CoreBindingHelper.BindCoreUntyped)}}({{Identifier.section}}, {{Identifier.obj}}, typeof({{Identifier.TOptions}}), {{Identifier.configureOptions}});
+                    """);
 
-                _writer.WriteBlockEnd(");");
+                EmitEndBlock(endBraceTrailingSource: ");");
 
-                _writer.WriteBlankLine();
+                _writer.WriteLine();
 
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     {{FullyQualifiedDisplayString.AddSingleton}}<{{FullyQualifiedDisplayString.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>, {{FullyQualifiedDisplayString.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>>({{Identifier.optionsBuilder}}.{{Identifier.Services}});
                     return {{Identifier.optionsBuilder}};
                     """);
 
-                _writer.WriteBlockEnd();
+                EmitEndBlock();
             }
 
-            private void EmitMethodBlockStart(string methodName, string paramList, string documentation)
+            private void EmitMethodStartBlock(string methodName, string paramList, string documentation)
             {
                 paramList = $"this {FullyQualifiedDisplayString.OptionsBuilderOfTOptions} {Identifier.optionsBuilder}, {paramList}";
 
                 EmitBlankLineIfRequired();
                 _writer.WriteLine(documentation);
-                _writer.WriteBlockStart($"public static {FullyQualifiedDisplayString.OptionsBuilderOfTOptions} {methodName}<{Identifier.TOptions}>({paramList}) where {Identifier.TOptions} : class");
+                EmitStartBlock($"public static {FullyQualifiedDisplayString.OptionsBuilderOfTOptions} {methodName}<{Identifier.TOptions}>({paramList}) where {Identifier.TOptions} : class");
             }
         }
     }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Helpers/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -9,14 +9,14 @@ private sealed partial class Emitter
         {
             private bool ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection methods) => (_sourceGenSpec.MethodsToGen_ServiceCollectionExt & methods) != 0;
 
-            private void EmitBinder_Extensions_ServiceCollection()
+            private void EmitBinder_Extensions_IServiceCollection()
             {
                 if (!ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection.Any))
                 {
                     return;
                 }
 
-                EmitRootBindingClassBlockStart(Identifier.GeneratedServiceCollectionBinder);
+                EmitRootBindingClassStartBlock(Identifier.GeneratedServiceCollectionBinder);
 
                 const string defaultNameExpr = "string.Empty";
                 const string configureMethodString = $"global::{Identifier.GeneratedServiceCollectionBinder}.{Identifier.Configure}";
@@ -24,56 +24,56 @@ private void EmitBinder_Extensions_ServiceCollection()
 
                 if (ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection.Configure_T))
                 {
-                    EmitBlockStart(configParam);
+                    EmitStartMethod(configParam);
                     _writer.WriteLine($"return {configureMethodString}<{Identifier.TOptions}>({Identifier.services}, {defaultNameExpr}, {Identifier.configuration}, {Identifier.configureOptions}: null);");
-                    _writer.WriteBlockEnd();
+                    EmitEndBlock();
                 }
 
                 if (ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection.Configure_T_name))
                 {
-                    EmitBlockStart(
+                    EmitStartMethod(
                         paramList: $"string? {Identifier.name}, " + configParam);
                     _writer.WriteLine($"return {configureMethodString}<{Identifier.TOptions}>({Identifier.services}, {Identifier.name}, {Identifier.configuration}, {Identifier.configureOptions}: null);");
-                    _writer.WriteBlockEnd();
+                    EmitEndBlock();
                 }
 
                 if (ShouldEmitMethods(MethodsToGen_Extensions_ServiceCollection.Configure_T_BinderOptions))
                 {
-                    EmitBlockStart(
+                    EmitStartMethod(
                         paramList: configParam + $", {FullyQualifiedDisplayString.ActionOfBinderOptions}? {Identifier.configureOptions}");
                     _writer.WriteLine($"return {configureMethodString}<{Identifier.TOptions}>({Identifier.services}, {defaultNameExpr}, {Identifier.configuration}, {Identifier.configureOptions});");
-                    _writer.WriteBlockEnd();
+                    EmitEndBlock();
                 }
 
+                // Core Configure method that the other overloads call.
+                // Like the others, it is public API that could be called directly by users.
+                // So, it is always generated whenever a Configure overload is called.
                 string optionsNamespaceName = "global::Microsoft.Extensions.Options";
                 string bindCoreUntypedDisplayString = GetHelperMethodDisplayString(nameof(MethodsToGen_CoreBindingHelper.BindCoreUntyped));
 
-                EmitBlockStart(paramList: $"string? {Identifier.name}, " + configParam + $", {FullyQualifiedDisplayString.ActionOfBinderOptions}? {Identifier.configureOptions}");
-
+                EmitStartMethod(paramList: $"string? {Identifier.name}, " + configParam + $", {FullyQualifiedDisplayString.ActionOfBinderOptions}? {Identifier.configureOptions}");
                 EmitCheckForNullArgument_WithBlankLine(Identifier.services);
                 EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
-
-                _writer.WriteBlock($$"""
+                _writer.WriteLine($$"""
                     global::Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
                     {{FullyQualifiedDisplayString.AddSingleton}}<{{FullyQualifiedDisplayString.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>({{Identifier.services}}, new {{FullyQualifiedDisplayString.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.configuration}}));
                     return {{FullyQualifiedDisplayString.AddSingleton}}<{{optionsNamespaceName}}.IConfigureOptions<{{Identifier.TOptions}}>>({{Identifier.services}}, new {{optionsNamespaceName}}.ConfigureNamedOptions<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.obj}} => {{bindCoreUntypedDisplayString}}({{Identifier.configuration}}, {{Identifier.obj}}, typeof({{Identifier.TOptions}}), {{Identifier.configureOptions}})));
-                }
-                """);
+                    """);
+                EmitEndBlock();
 
-                _writer.WriteBlockEnd();
+                EmitEndBlock();
                 _emitBlankLineBeforeNextStatement = true;
             }
 
-            private void EmitBlockStart(string paramList)
+            private void EmitStartMethod(string paramList)
             {
                 paramList = $"this {FullyQualifiedDisplayString.IServiceCollection} {Identifier.services}, {paramList}";
 
                 EmitBlankLineIfRequired();
-                _writer.WriteBlock($$"""
-                /// <summary>Registers a configuration instance which TOptions will bind against.</summary>
-                public static {{FullyQualifiedDisplayString.IServiceCollection}} {{Identifier.Configure}}<{{Identifier.TOptions}}>({{paramList}}) where {{Identifier.TOptions}} : class
-                {
-                """);
+                EmitStartBlock($$"""
+                    /// <summary>Registers a configuration instance which TOptions will bind against.</summary>
+                    public static {{FullyQualifiedDisplayString.IServiceCollection}} {{Identifier.Configure}}<{{Identifier.TOptions}}>({{paramList}}) where {{Identifier.TOptions}} : class
+                    """);
             }
         }
     }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Helpers/SourceWriter.cs

-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-using System;
-using System.Diagnostics;
-using System.Text;
-using Microsoft.CodeAnalysis.Text;
-
-namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
-{
-    internal sealed class SourceWriter
-    {
-        private readonly StringBuilder _sb = new();
-        private static readonly char[] s_newLine = Environment.NewLine.ToCharArray();
-        private int _indentation;
-
-        public void WriteBlockStart(string? declaration = null)
-        {
-            if (declaration is not null)
-            {
-                WriteLine(declaration);
-            }
-            WriteLine("{");
-            _indentation++;
-        }
-
-        public void WriteBlockEnd(string? extra = null)
-        {
-            _indentation--;
-            Debug.Assert(_indentation > -1);
-            WriteLine($"}}{extra}");
-        }
-
-        public void WriteLine(string source)
-        {
-            _sb.Append(' ', 4 * _indentation);
-            _sb.AppendLine(source);
-        }
-
-        public void WriteBlock(string source)
-        {
-            bool isFinalLine;
-            ReadOnlySpan<char> remainingText = source.AsSpan();
-
-            do
-            {
-                ReadOnlySpan<char> line = GetNextLine(ref remainingText, out isFinalLine);
-                switch (line)
-                {
-                    case "{":
-                        {
-                            WriteBlockStart();
-                        }
-                        break;
-                    case "}":
-                        {
-                            WriteBlockEnd();
-                        }
-                        break;
-                    default:
-                        {
-                            WriteLine(line);
-                        }
-                        break;
-                }
-            } while (!isFinalLine);
-        }
-
-        public void WriteBlankLine() => _sb.AppendLine();
-
-        public SourceText ToSourceText()
-        {
-            Debug.Assert(_indentation == 0 && _sb.Length > 0);
-            return SourceText.From(_sb.ToString(), Encoding.UTF8);
-        }
-
-        private static ReadOnlySpan<char> GetNextLine(ref ReadOnlySpan<char> remainingText, out bool isFinalLine)
-        {
-            if (remainingText.IsEmpty)
-            {
-                isFinalLine = true;
-                return default;
-            }
-
-            ReadOnlySpan<char> next;
-            ReadOnlySpan<char> rest;
-
-            remainingText = remainingText.Trim();
-
-            int lineLength = remainingText.IndexOf(s_newLine);
-            if (lineLength == -1)
-            {
-                lineLength = remainingText.Length;
-                isFinalLine = true;
-                rest = default;
-            }
-            else
-            {
-                rest = remainingText.Slice(lineLength + 1);
-                isFinalLine = false;
-            }
-
-            next = remainingText.Slice(0, lineLength);
-            remainingText = rest;
-            return next;
-        }
-
-        private unsafe void WriteLine(ReadOnlySpan<char> source)
-        {
-            _sb.Append(' ', 4 * _indentation);
-            fixed (char* ptr = source)
-            {
-                _sb.Append(ptr, source.Length);
-                WriteBlankLine();
-            }
-        }
-    }
-}

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Microsoft.Extensions.Configuration.Binder.SourceGeneration.csproj

@@ -21,6 +21,7 @@
     <Compile Include="$(CoreLibSharedDir)System\Collections\Generic\ValueListBuilder.cs" Link="Production\ValueListBuilder.cs" />
     <Compile Include="$(CoreLibSharedDir)System\Collections\Generic\ValueListBuilder.Pop.cs" Link="Production\ValueListBuilder.Pop.cs" />
     <Compile Include="$(CommonPath)\Roslyn\GetBestTypeByMetadataName.cs" Link="Common\Roslyn\GetBestTypeByMetadataName.cs" />
+    <Compile Include="$(CommonPath)\SourceGenerators\SourceWriter.cs" Link="Common\SourceGenerators\SourceWriter.cs" />
     <Compile Include="ConfigurationBindingGenerator.cs" />
     <Compile Include="ConfigurationBindingGenerator.Emitter.cs" />
     <Compile Include="ConfigurationBindingGenerator.Parser.cs" />
@@ -36,7 +37,6 @@
     <Compile Include="Helpers\Parser\Diagnostics.cs" />
     <Compile Include="Helpers\Parser\OptionsBuilderConfigurationExtensions.cs" />
     <Compile Include="Helpers\Parser\OptionsConfigurationServiceCollectionExtensions.cs" />
-    <Compile Include="Helpers\SourceWriter.cs" />
     <Compile Include="Model\CollectionSpec.cs" />
     <Compile Include="Model\ConfigurationSectionSpec.cs" />
     <Compile Include="Model\InitializationStrategy.cs" />

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/Collections.generated.txt

@@ -235,6 +235,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -242,6 +243,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -273,12 +275,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Bind.generated.txt

@@ -126,6 +126,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -133,6 +134,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -155,12 +157,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Bind_Instance.generated.txt

@@ -120,6 +120,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -127,6 +128,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Bind_Instance_BinderOptions.generated.txt

@@ -120,6 +120,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -127,6 +128,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -149,12 +151,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Bind_Key_Instance.generated.txt

@@ -120,6 +120,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -127,6 +128,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Get.generated.txt

@@ -173,6 +173,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -180,6 +181,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -211,12 +213,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Get_T.generated.txt

@@ -141,6 +141,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -148,6 +149,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -179,12 +181,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Get_T_BinderOptions.generated.txt

@@ -141,6 +141,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -148,6 +149,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -179,12 +181,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Get_TypeOf.generated.txt

@@ -69,6 +69,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -76,6 +77,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -107,12 +109,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ConfigurationBinder/Get_TypeOf_BinderOptions.generated.txt

@@ -69,6 +69,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -76,6 +77,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -107,12 +109,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/OptionsBuilder/BindConfiguration.generated.txt

@@ -116,6 +116,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -123,6 +124,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -154,12 +156,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/OptionsBuilder/Bind_T.generated.txt

@@ -134,6 +134,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -141,6 +142,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -172,12 +174,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/OptionsBuilder/Bind_T_BinderOptions.generated.txt

@@ -128,6 +128,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -135,6 +136,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -166,12 +168,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/Primitives.generated.txt

@@ -174,6 +174,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -181,6 +182,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ServiceCollection/Configure_T.generated.txt

@@ -179,6 +179,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -186,6 +187,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -217,12 +219,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ServiceCollection/Configure_T_BinderOptions.generated.txt

@@ -179,6 +179,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -186,6 +187,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -217,12 +219,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ServiceCollection/Configure_T_name.generated.txt

@@ -179,6 +179,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -186,6 +187,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -217,12 +219,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/Baselines/ServiceCollection/Configure_T_name_BinderOptions.generated.txt

@@ -173,6 +173,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             if (binderOptions?.ErrorOnUnknownConfiguration is true)
             {
                 List<string>? temp = null;
+        
                 foreach (IConfigurationSection section in configuration.GetChildren())
                 {
                     if (!keys.Value.Contains(section.Key))
@@ -180,6 +181,7 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
                         (temp ??= new List<string>()).Add($"'{section.Key}'");
                     }
                 }
+        
                 if (temp is not null)
                 {
                     throw new InvalidOperationException($"'ErrorOnUnknownConfiguration' was set on the provided BinderOptions, but the following properties were not found on the instance of {type}: {string.Join(", ", temp)}");
@@ -211,12 +213,15 @@ namespace Microsoft.Extensions.Configuration.Binder.SourceGeneration
             {
                 return null;
             }
+        
             BinderOptions binderOptions = new();
             configureOptions(binderOptions);
+        
             if (binderOptions.BindNonPublicProperties)
             {
                 throw new global::System.NotSupportedException($"The configuration binding source generator does not support 'BinderOptions.BindNonPublicProperties'.");
             }
+        
             return binderOptions;
         }
 

src/libraries/Microsoft.Extensions.Configuration.Binder/tests/SourceGenerationTests/ConfigurationBindingGeneratorTests.cs

@@ -257,8 +257,7 @@ public class MyClass2 { }
                                              .Split(Environment.NewLine);
 
             var (d, r) = await RunGenerator(testSourceCode, languageVersion);
-            bool success = RoslynTestUtils.CompareLines(expectedLines, r[0].SourceText,
-                out string errorMessage);
+            bool success = RoslynTestUtils.CompareLines(expectedLines, r[0].SourceText, out string errorMessage);
 
 #if !SKIP_BASELINES
             Assert.Single(r);

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Emitter.cs

@@ -10,6 +10,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Text;
+using SourceGenerators;
 
 namespace System.Text.Json.SourceGeneration
 {

src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets

@@ -28,6 +28,8 @@
     <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\IsExternalInit.cs" Link="Common\System\Runtime\CompilerServices\IsExternalInit.cs" />
     <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\CompilerFeatureRequiredAttribute.cs" Link="Common\System\Runtime\CompilerServices\CompilerFeatureRequiredAttribute.cs" />
     <Compile Include="$(CoreLibSharedDir)System\Runtime\CompilerServices\RequiredMemberAttribute.cs" Link="Common\System\Runtime\CompilerServices\RequiredMemberAttribute.cs" />
+    <Compile Include="$(CommonPath)\Roslyn\GetBestTypeByMetadataName.cs" Link="Common\Roslyn\GetBestTypeByMetadataName.cs" />
+    <Compile Include="$(CommonPath)\SourceGenerators\SourceWriter.cs" Link="Common\SourceGenerators\SourceWriter.cs" />
     <Compile Include="..\Common\JsonCamelCaseNamingPolicy.cs" Link="Common\System\Text\Json\JsonCamelCaseNamingPolicy.cs" />
     <Compile Include="..\Common\JsonNamingPolicy.cs" Link="Common\System\Text\Json\JsonNamingPolicy.cs" />
     <Compile Include="..\Common\JsonAttribute.cs" Link="Common\System\Text\Json\Serialization\JsonAttribute.cs" />
@@ -50,13 +52,11 @@
     <Compile Include="..\Common\JsonUnknownTypeHandling.cs" Link="Common\System\Text\Json\Serialization\JsonUnknownTypeHandling.cs" />
     <Compile Include="..\Common\JsonUnmappedMemberHandling.cs" Link="Common\System\Text\Json\Serialization\JsonUnmappedMemberHandling.cs" />
     <Compile Include="..\Common\ThrowHelper.cs" Link="Common\System\Text\Json\ThrowHelper.cs" />
-    <Compile Include="$(CommonPath)\Roslyn\GetBestTypeByMetadataName.cs" Link="Common\Roslyn\GetBestTypeByMetadataName.cs" />
     <Compile Include="Helpers\DiagnosticInfo.cs" />
     <Compile Include="Helpers\SourceGeneratorHelpers.cs" />
     <Compile Include="Helpers\ImmutableEquatableArray.cs" />
     <Compile Include="Helpers\KnownTypeSymbols.cs" />
     <Compile Include="Helpers\RoslynExtensions.cs" />
-    <Compile Include="Helpers\SourceWriter.cs" />
     <Compile Include="JsonConstants.cs" />
     <Compile Include="JsonSourceGenerator.DiagnosticDescriptors.cs" />
     <Compile Include="JsonSourceGenerator.Emitter.cs" />