Respect tabs vs spaces when generating code

src/Razor/src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/CodeWriter.cs

@@ -18,9 +18,16 @@ public sealed class CodeWriter
         private int _currentLineIndex;
         private int _currentLineCharacterIndex;
 
-        public CodeWriter()
+        public CodeWriter() : this(Environment.NewLine, 4, false)
         {
-            NewLine = Environment.NewLine;
+        }
+
+        public CodeWriter(string newLine, int tabSize, bool indentWithTabs)
+        {
+            NewLine = newLine;
+            TabSize = tabSize;
+            IndentWithTabs = indentWithTabs;
+
             _builder = new StringBuilder();
         }
 
@@ -47,6 +54,10 @@ public string NewLine
             }
         }
 
+        public int TabSize { get; set; }
+
+        public bool IndentWithTabs { get; set; }
+
         public SourceLocation Location => new SourceLocation(_absoluteIndex, _currentLineIndex, _currentLineCharacterIndex);
 
         public char this[int index]
@@ -62,15 +73,40 @@ public char this[int index]
             }
         }
 
-        // Internal for testing.
-        internal CodeWriter Indent(int size)
+        public CodeWriter Indent(int size)
         {
             if (Length == 0 || this[Length - 1] == '\n')
             {
-                _builder.Append(' ', size);
+                var actualSize = 0;
+                if (IndentWithTabs)
+                {
+                    // Avoid writing directly to the StringBuilder here, that will throw off the manual indexing 
+                    // done by the base class.
+                    var tabs = size / TabSize;
+                    actualSize += tabs;
+                    for (var i = 0; i < tabs; i++)
+                    {
+                        _builder.Append("\t");
+                    }
+
+                    var spaces = size % TabSize;
+                    actualSize += spaces;
+                    for (var i = 0; i < spaces; i++)
+                    {
+                        _builder.Append(" ");
+                    }
+                }
+                else
+                {
+                    actualSize = size;
+                    for (var i = 0; i < size; i++)
+                    {
+                        _builder.Append(" ");
+                    }
+                }
 
-                _currentLineCharacterIndex += size;
-                _absoluteIndex += size;
+                _currentLineCharacterIndex += actualSize;
+                _absoluteIndex += actualSize;
             }
 
             return this;

src/Razor/src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/CodeWriterExtensions.cs

@@ -48,29 +48,7 @@ public static CodeWriter WritePadding(this CodeWriter writer, int offset, Source
             var basePadding = CalculatePadding();
             var resolvedPadding = Math.Max(basePadding - offset, 0);
 
-            if (context.Options.IndentWithTabs)
-            {
-                // Avoid writing directly to the StringBuilder here, that will throw off the manual indexing 
-                // done by the base class.
-                var tabs = resolvedPadding / context.Options.IndentSize;
-                for (var i = 0; i < tabs; i++)
-                {
-                    writer.Write("\t");
-                }
-
-                var spaces = resolvedPadding % context.Options.IndentSize;
-                for (var i = 0; i < spaces; i++)
-                {
-                    writer.Write(" ");
-                }
-            }
-            else
-            {
-                for (var i = 0; i < resolvedPadding; i++)
-                {
-                    writer.Write(" ");
-                }
-            }
+            writer.Indent(resolvedPadding);
 
             return writer;
 
@@ -86,7 +64,7 @@ int CalculatePadding()
                     }
                     else if (@char == '\t')
                     {
-                        spaceCount += context.Options.IndentSize;
+                        spaceCount += writer.TabSize;
                     }
                     else
                     {
@@ -569,11 +547,11 @@ public struct CSharpCodeWritingScope : IDisposable
             private int _tabSize;
             private int _startIndent;
 
-            public CSharpCodeWritingScope(CodeWriter writer, int tabSize = 4, bool autoSpace = true)
+            public CSharpCodeWritingScope(CodeWriter writer, bool autoSpace = true)
             {
                 _writer = writer;
                 _autoSpace = autoSpace;
-                _tabSize = tabSize;
+                _tabSize = writer.TabSize;
                 _startIndent = -1; // Set in WriteStartScope
 
                 WriteStartScope();

src/Razor/src/Microsoft.AspNetCore.Razor.Language/CodeGeneration/DefaultDocumentWriter.cs

@@ -32,7 +32,7 @@ public override RazorCSharpDocument WriteDocument(RazorCodeDocument codeDocument
             }
 
             var context = new DefaultCodeRenderingContext(
-                new CodeWriter(),
+                new CodeWriter(Environment.NewLine, _options.IndentSize, _options.IndentWithTabs),
                 _codeTarget.CreateNodeWriter(),
                 codeDocument,
                 documentNode,

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DefaultProjectSnapshotManagerAccessor.cs

@@ -9,6 +9,7 @@
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer
 {
@@ -17,12 +18,14 @@ internal class DefaultProjectSnapshotManagerAccessor : ProjectSnapshotManagerAcc
         private readonly ForegroundDispatcher _foregroundDispatcher;
         private readonly IEnumerable<ProjectSnapshotChangeTrigger> _changeTriggers;
         private readonly FilePathNormalizer _filePathNormalizer;
+        private readonly IOptionsMonitor<RazorLSPOptions> _optionsMonitor;
         private ProjectSnapshotManagerBase _instance;
 
         public DefaultProjectSnapshotManagerAccessor(
             ForegroundDispatcher foregroundDispatcher,
             IEnumerable<ProjectSnapshotChangeTrigger> changeTriggers,
-            FilePathNormalizer filePathNormalizer)
+            FilePathNormalizer filePathNormalizer,
+            IOptionsMonitor<RazorLSPOptions> optionsMonitor)
         {
             if (foregroundDispatcher == null)
             {
@@ -39,9 +42,15 @@ public DefaultProjectSnapshotManagerAccessor(
                 throw new ArgumentNullException(nameof(filePathNormalizer));
             }
 
+            if (optionsMonitor is null)
+            {
+                throw new ArgumentNullException(nameof(optionsMonitor));
+            }
+
             _foregroundDispatcher = foregroundDispatcher;
             _changeTriggers = changeTriggers;
             _filePathNormalizer = filePathNormalizer;
+            _optionsMonitor = optionsMonitor;
         }
 
         public override ProjectSnapshotManagerBase Instance
@@ -53,7 +62,7 @@ public override ProjectSnapshotManagerBase Instance
                     var services = AdhocServices.Create(
                         workspaceServices: new[]
                         {
-                            new RemoteProjectSnapshotProjectEngineFactory(_filePathNormalizer)
+                            new RemoteProjectSnapshotProjectEngineFactory(_filePathNormalizer, _optionsMonitor)
                         },
                         razorLanguageServices: Enumerable.Empty<ILanguageService>());
                     var workspace = new AdhocWorkspace(services);

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DefaultRazorConfigurationService.cs

@@ -41,6 +41,10 @@ public async override Task<RazorLSPOptions> GetLatestOptionsAsync()
                 {
                     Items = new[]
                     {
+                        new ConfigurationItem()
+                        {
+                            Section = "editor"
+                        },
                         new ConfigurationItem()
                         {
                             Section = "razor"
@@ -49,16 +53,22 @@ public async override Task<RazorLSPOptions> GetLatestOptionsAsync()
                 };
 
                 var result = await _server.Client.SendRequest<ConfigurationParams, object[]>("workspace/configuration", request);
-                if (result == null || result.Length < 1 || result[0] == null)
+                if (result == null || result.Length < 2 || result[0] == null)
                 {
                     _logger.LogWarning("Client failed to provide the expected configuration.");
                     return null;
                 }
 
-                var jsonString = result[0].ToString();
                 var builder = new ConfigurationBuilder();
-                using var stream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
-                builder.AddJsonStream(stream);
+
+                var editorJsonString = result[0].ToString();
+                using var editorStream = new MemoryStream(Encoding.UTF8.GetBytes(editorJsonString));
+                builder.AddJsonStream(editorStream);
+
+                var razorJsonString = result[1].ToString();
+                using var razorStream = new MemoryStream(Encoding.UTF8.GetBytes(razorJsonString));
+                builder.AddJsonStream(razorStream);
+
                 var config = builder.Build();
 
                 var instance = BuildOptions(config);
@@ -83,7 +93,19 @@ private RazorLSPOptions BuildOptions(IConfiguration config)
                 enableFormatting = parsedEnableFormatting;
             }
 
-            return new RazorLSPOptions(trace, enableFormatting);
+            var tabSize = instance.TabSize;
+            if (int.TryParse(config["tabSize"], out var parsedTabSize))
+            {
+                tabSize = parsedTabSize;
+            }
+
+            var insertSpaces = instance.InsertSpaces;
+            if (bool.TryParse(config["insertSpaces"], out var parsedInsertSpaces))
+            {
+                insertSpaces = parsedInsertSpaces;
+            }
+
+            return new RazorLSPOptions(trace, enableFormatting, tabSize, insertSpaces);
         }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorLSPOptions.cs

@@ -10,20 +10,26 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
 {
     internal class RazorLSPOptions : IEquatable<RazorLSPOptions>
     {
-        public RazorLSPOptions(Trace trace, bool enableFormatting)
+        public RazorLSPOptions(Trace trace, bool enableFormatting, int tabSize, bool insertSpaces)
         {
             Trace = trace;
             EnableFormatting = enableFormatting;
+            TabSize = tabSize;
+            InsertSpaces = insertSpaces;
         }
 
-        public static RazorLSPOptions Default => new RazorLSPOptions(trace: default, enableFormatting: true);
+        public static RazorLSPOptions Default => new RazorLSPOptions(trace: default, enableFormatting: true, tabSize: 4, insertSpaces: true);
 
         public Trace Trace { get; }
 
         public LogLevel MinLogLevel => GetLogLevelForTrace(Trace);
 
         public bool EnableFormatting { get; }
 
+        public int TabSize { get; }
+
+        public bool InsertSpaces { get; }
+
         public static LogLevel GetLogLevelForTrace(Trace trace)
         {
             return trace switch

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RemoteProjectSnapshotProjectEngineFactory.cs

@@ -7,6 +7,7 @@
 using Microsoft.AspNetCore.Razor.LanguageServer.Common;
 using Microsoft.AspNetCore.Razor.LanguageServer.ProjectSystem;
 using Microsoft.CodeAnalysis.Razor;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer
 {
@@ -15,16 +16,23 @@ internal class RemoteProjectSnapshotProjectEngineFactory : DefaultProjectSnapsho
         public static readonly IFallbackProjectEngineFactory FallbackProjectEngineFactory = new FallbackProjectEngineFactory();
 
         private readonly FilePathNormalizer _filePathNormalizer;
+        private readonly IOptionsMonitor<RazorLSPOptions> _optionsMonitor;
 
-        public RemoteProjectSnapshotProjectEngineFactory(FilePathNormalizer filePathNormalizer) : 
+        public RemoteProjectSnapshotProjectEngineFactory(FilePathNormalizer filePathNormalizer, IOptionsMonitor<RazorLSPOptions> optionsMonitor) : 
             base(FallbackProjectEngineFactory, ProjectEngineFactories.Factories)
         {
             if (filePathNormalizer == null)
             {
                 throw new ArgumentNullException(nameof(filePathNormalizer));
             }
 
+            if (optionsMonitor is null)
+            {
+                throw new ArgumentNullException(nameof(optionsMonitor));
+            }
+
             _filePathNormalizer = filePathNormalizer;
+            _optionsMonitor = optionsMonitor;
         }
 
         public override RazorProjectEngine Create(
@@ -39,7 +47,37 @@ public override RazorProjectEngine Create(
             }
 
             var remoteFileSystem = new RemoteRazorProjectFileSystem(defaultFileSystem.Root, _filePathNormalizer);
-            return base.Create(configuration, remoteFileSystem, configure);
+            return base.Create(configuration, remoteFileSystem, Configure);
+
+            void Configure(RazorProjectEngineBuilder builder)
+            {
+                configure(builder);
+                builder.Features.Add(new RemoteCodeGenerationOptionsFeature(_optionsMonitor));
+            }
+        }
+
+        private class RemoteCodeGenerationOptionsFeature : RazorEngineFeatureBase, IConfigureRazorCodeGenerationOptionsFeature
+        {
+            private readonly IOptionsMonitor<RazorLSPOptions> _optionsMonitor;
+
+            public RemoteCodeGenerationOptionsFeature(IOptionsMonitor<RazorLSPOptions> optionsMonitor)
+            {
+                if (optionsMonitor is null)
+                {
+                    throw new ArgumentNullException(nameof(optionsMonitor));
+                }
+
+                _optionsMonitor = optionsMonitor;
+            }
+
+            public int Order { get; set; }
+
+            public void Configure(RazorCodeGenerationOptionsBuilder options)
+            {
+                // We don't need to explicitly subscribe to options changing because this method will be run on every parse.
+                options.IndentSize = _optionsMonitor.CurrentValue.TabSize;
+                options.IndentWithTabs = !_optionsMonitor.CurrentValue.InsertSpaces;
+            }
         }
     }
 }

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DefaultRazorConfigurationServiceTest.cs

@@ -17,16 +17,22 @@ public class DefaultRazorConfigurationServiceTest : LanguageServerTestBase
         public async Task GetLatestOptionsAsync_ReturnsExpectedOptions()
         {
             // Arrange
-            var expectedOptions = new RazorLSPOptions(Trace.Messages, enableFormatting: false);
-            var jsonString = @"
+            var expectedOptions = new RazorLSPOptions(Trace.Messages, enableFormatting: false, tabSize: 8, insertSpaces: true);
+            var editorJsonString = @"
+{
+  ""tabSize"": 8,
+  ""insertSpaces"": ""true""
+}
+".Trim();
+            var razorJsonString = @"
 {
   ""trace"": ""Messages"",
   ""format"": {
     ""enable"": ""false""
   }
 }
 ".Trim();
-            var result = new object[] { jsonString };
+            var result = new object[] { editorJsonString, razorJsonString };
             var languageServer = GetLanguageServer(result);
             var configurationService = new DefaultRazorConfigurationService(languageServer, LoggerFactory);
 

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting/RazorFormattingEndpointTest.cs

@@ -111,7 +111,7 @@ public async Task Handle_FormattingDisabled_ReturnsNull()
         private static IOptionsMonitor<RazorLSPOptions> GetOptionsMonitor(bool enableFormatting)
         {
             var monitor = new Mock<IOptionsMonitor<RazorLSPOptions>>();
-            monitor.SetupGet(m => m.CurrentValue).Returns(new RazorLSPOptions(default, enableFormatting));
+            monitor.SetupGet(m => m.CurrentValue).Returns(new RazorLSPOptions(default, enableFormatting, tabSize: 4, insertSpaces: true));
             return monitor.Object;
         }