Move indentation service to VS.Editor.Razor and export it.

- Removed indentation service extensions and made `GetDesiredIndentation` understand `ITextSnapshot`s and `ITextLineSnapshot`.
- Updated our test `StringTextSnapshot` implementation to have the required features our indentation tests require.
- Updated indentation service tests to use new API.

#1762

src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultRazorIndentationFactsServiceFactory.cs

@@ -1,19 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Composition;
-using Microsoft.CodeAnalysis.Host;
-using Microsoft.CodeAnalysis.Host.Mef;
-
-namespace Microsoft.CodeAnalysis.Razor
-{
-    [Shared]
-    [ExportLanguageServiceFactory(typeof(RazorIndentationFactsService), RazorLanguage.Name, ServiceLayer.Default)]
-    internal class DefaultRazorIndentationFactsServiceFactory : ILanguageServiceFactory
-    {
-        public ILanguageService CreateLanguageService(HostLanguageServices languageServices)
-        {
-            return new DefaultRazorIndentationFactsService();
-        }
-    }
-}

src/Microsoft.VisualStudio.Editor.Razor/DefaultRazorIndentationFactsService.cs

@@ -3,28 +3,38 @@
 
 using System;
 using System.Collections.Generic;
+using System.ComponentModel.Composition;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.Legacy;
+using Microsoft.VisualStudio.Text;
+using Span = Microsoft.AspNetCore.Razor.Language.Legacy.Span;
 
-namespace Microsoft.CodeAnalysis.Razor
+namespace Microsoft.VisualStudio.Editor.Razor
 {
+    [System.Composition.Shared]
+    [Export(typeof(RazorIndentationFactsService))]
     internal class DefaultRazorIndentationFactsService : RazorIndentationFactsService
     {
-        public override int? GetDesiredIndentation(RazorSyntaxTree syntaxTree, int previousLineEndIndex, Func<int, string> getLineContent, int indentSize, int tabSize)
+        public override int? GetDesiredIndentation(
+            RazorSyntaxTree syntaxTree,
+            ITextSnapshot syntaxTreeSnapshot,
+            ITextSnapshotLine line,
+            int indentSize,
+            int tabSize)
         {
             if (syntaxTree == null)
             {
                 throw new ArgumentNullException(nameof(syntaxTree));
             }
 
-            if (previousLineEndIndex < 0)
+            if (syntaxTreeSnapshot == null)
             {
-                throw new ArgumentOutOfRangeException(nameof(previousLineEndIndex));
+                throw new ArgumentNullException(nameof(syntaxTreeSnapshot));
             }
 
-            if (getLineContent == null)
+            if (line == null)
             {
-                throw new ArgumentNullException(nameof(getLineContent));
+                throw new ArgumentNullException(nameof(line));
             }
 
             if (indentSize < 0)
@@ -37,6 +47,10 @@ namespace Microsoft.CodeAnalysis.Razor
                 throw new ArgumentOutOfRangeException(nameof(tabSize));
             }
 
+            var previousLine = line.Snapshot.GetLineFromLineNumber(line.LineNumber - 1);
+            var trackingPoint = previousLine.Snapshot.CreateTrackingPoint(previousLine.End, PointTrackingMode.Negative);
+            var previousLineEndIndex = trackingPoint.GetPosition(syntaxTreeSnapshot);
+
             var simulatedChange = new SourceChange(previousLineEndIndex, 0, string.Empty);
             var owningSpan = LocateOwner(syntaxTree.Root, simulatedChange);
             if (owningSpan.Kind == SpanKindInternal.Code)
@@ -80,8 +94,8 @@ namespace Microsoft.CodeAnalysis.Razor
                             // We can't rely on the syntax trees representation of the source document because partial parses may have mutated
                             // the underlying SyntaxTree text buffer. Because of this, if we want to provide accurate indentations we need to
                             // operate on the current line representation as indicated by the provider.
-                            var line = getLineContent(currentSpan.Start.LineIndex);
+                            var lineText = line.Snapshot.GetLineFromLineNumber(currentSpan.Start.LineIndex).GetText();
-                            desiredIndentation = GetIndentLevelOfLine(line, tabSize) + indentSize;
+                            desiredIndentation = GetIndentLevelOfLine(lineText, tabSize) + indentSize;
                         }
                     }
 

src/Microsoft.VisualStudio.Editor.Razor/RazorIndentationFactsService.cs

@@ -1,14 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Host;
+using Microsoft.VisualStudio.Text;
 
-namespace Microsoft.CodeAnalysis.Razor
+namespace Microsoft.VisualStudio.Editor.Razor
 {
     public abstract class RazorIndentationFactsService : ILanguageService
     {
-        public abstract int? GetDesiredIndentation(RazorSyntaxTree syntaxTree, int previousLineEnd, Func<int, string> lineProvider, int indentSize, int tabSize);
+        public abstract int? GetDesiredIndentation(RazorSyntaxTree syntaxTree, ITextSnapshot syntaxTreeSnapshot, ITextSnapshotLine line, int indentSize, int tabSize);
     }
 }

src/Microsoft.VisualStudio.Editor.Razor/RazorIndentationFactsServiceExtensions.cs

@@ -1,30 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using Microsoft.AspNetCore.Razor.Language;
-using Microsoft.VisualStudio.Text;
-
-namespace Microsoft.CodeAnalysis.Razor
-{
-    public static class RazorIndentationFactsServiceExtensions
-    {
-        public static int? GetDesiredIndentation(
-            this RazorIndentationFactsService service,
-            RazorSyntaxTree syntaxTree,
-            ITextSnapshot syntaxTreeSnapshot,
-            ITextSnapshotLine line,
-            int indentSize,
-            int tabSize)
-        {
-            // The tricky thing here is that line.Snapshot is very likely newer
-            var previousLine = line.Snapshot.GetLineFromLineNumber(line.LineNumber - 1);
-            var trackingPoint = line.Snapshot.CreateTrackingPoint(line.End, PointTrackingMode.Negative);
-            var previousLineEnd = trackingPoint.GetPosition(syntaxTreeSnapshot);
-
-            Func<int, string> getLineContentDelegate = (lineIndex) => line.Snapshot.GetLineFromLineNumber(lineIndex).GetText();
-
-            return service.GetDesiredIndentation(syntaxTree, previousLineEnd, getLineContentDelegate, indentSize, tabSize);
-        }
-    }
-}

test/Microsoft.VisualStudio.Editor.Razor.Test.Common/StringTextSnapshot.cs

@@ -77,7 +77,20 @@ namespace Microsoft.VisualStudio.Text
             return matchingLine;
         }
 
-        public ITrackingPoint CreateTrackingPoint(int position, PointTrackingMode trackingMode) => throw new NotImplementedException();
+        public ITextSnapshotLine GetLineFromLineNumber(int lineNumber)
+        {
+            if (lineNumber < 0 || lineNumber >= _lines.Count)
+            {
+                throw new ArgumentOutOfRangeException(nameof(lineNumber));
+            }
+
+            return _lines[lineNumber];
+        }
+
+        public ITrackingPoint CreateTrackingPoint(int position, PointTrackingMode trackingMode)
+        {
+            return new SnapshotTrackingPoint(position);
+        }
 
         public ITrackingPoint CreateTrackingPoint(int position, PointTrackingMode trackingMode, TrackingFidelityMode trackingFidelity) => throw new NotImplementedException();
 
@@ -89,8 +102,6 @@ namespace Microsoft.VisualStudio.Text
 
         public ITrackingSpan CreateTrackingSpan(int start, int length, SpanTrackingMode trackingMode, TrackingFidelityMode trackingFidelity) => throw new NotImplementedException();
 
-        public ITextSnapshotLine GetLineFromLineNumber(int lineNumber) => throw new NotImplementedException();
-
         public int GetLineNumberFromPosition(int position) => throw new NotImplementedException();
 
         public string GetText(VisualStudio.Text.Span span) => throw new NotImplementedException();
@@ -133,6 +144,30 @@ namespace Microsoft.VisualStudio.Text
             }
         }
 
+        private class SnapshotTrackingPoint : ITrackingPoint
+        {
+            private readonly int _position;
+
+            public SnapshotTrackingPoint(int position)
+            {
+                _position = position;
+            }
+
+            public ITextBuffer TextBuffer => throw new NotImplementedException();
+
+            public PointTrackingMode TrackingMode => throw new NotImplementedException();
+
+            public TrackingFidelityMode TrackingFidelity => throw new NotImplementedException();
+
+            public char GetCharacter(ITextSnapshot snapshot) => throw new NotImplementedException();
+
+            public SnapshotPoint GetPoint(ITextSnapshot snapshot) => throw new NotImplementedException();
+
+            public int GetPosition(ITextSnapshot snapshot) => _position;
+
+            public int GetPosition(ITextVersion version) => throw new NotImplementedException();
+        }
+
         private class SnapshotLine : ITextSnapshotLine
         {
             private readonly string _contentWithLineBreak;
@@ -153,7 +188,9 @@ namespace Microsoft.VisualStudio.Text
                 }
 
                 Start = new SnapshotPoint(owner, start);
+                End = new SnapshotPoint(owner, start + _content.Length);
                 Snapshot = owner;
+                LineNumber = (owner as StringTextSnapshot)._lines.Count;
             }
 
             public ITextSnapshot Snapshot { get; }
@@ -172,14 +209,14 @@ namespace Microsoft.VisualStudio.Text
 
             public string GetTextIncludingLineBreak() => _contentWithLineBreak;
 
-            public int LineNumber => throw new NotImplementedException();
+            public int LineNumber { get; }
+
+            public SnapshotPoint End { get; }
 
             public SnapshotSpan Extent => throw new NotImplementedException();
 
             public SnapshotSpan ExtentIncludingLineBreak => throw new NotImplementedException();
 
-            public SnapshotPoint End => throw new NotImplementedException();
-
             public SnapshotPoint EndIncludingLineBreak => throw new NotImplementedException();
         }
     }

test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultRazorIndentationFactsServiceTest.cs

@@ -1,13 +1,13 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.AspNetCore.Razor.Language;
+using Microsoft.VisualStudio.Text;
 using Xunit;
 
-namespace Microsoft.CodeAnalysis.Razor
+namespace Microsoft.VisualStudio.Editor.Razor
 {
     public class DefaultRazorIndentationFactsServiceTest
     {
@@ -15,17 +15,17 @@ namespace Microsoft.CodeAnalysis.Razor
         public void GetDesiredIndentation_ReturnsNull_IfOwningSpanIsCode()
         {
             // Arrange
-            var source = $@"
+            var source = new StringTextSnapshot($@"
 @{{
-";
+");
             var syntaxTree = GetSyntaxTree(source);
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 1),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(2),
                 indentSize: 4,
                 tabSize: 1);
 
@@ -38,17 +38,17 @@ namespace Microsoft.CodeAnalysis.Razor
         {
             // Arrange
             var customDirective = DirectiveDescriptor.CreateSingleLineDirective("custom");
-            var source = $@"
+            var source = new StringTextSnapshot($@"
 @custom
-";
+");
             var syntaxTree = GetSyntaxTree(source, new[] { customDirective });
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 1),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(2),
                 indentSize: 4,
                 tabSize: 1);
 
@@ -60,17 +60,17 @@ namespace Microsoft.CodeAnalysis.Razor
         public void GetDesiredIndentation_ReturnsCorrectIndentation_ForMarkupWithinCodeBlock()
         {
             // Arrange
-            var source = $@"@{{
+            var source = new StringTextSnapshot($@"@{{
     <div>
-";
+");
             var syntaxTree = GetSyntaxTree(source);
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 1),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(2),
                 indentSize: 4,
                 tabSize: 4);
 
@@ -83,18 +83,18 @@ namespace Microsoft.CodeAnalysis.Razor
         {
             // Arrange
             var customDirective = DirectiveDescriptor.CreateRazorBlockDirective("custom");
-            var source = $@"@custom
+            var source = new StringTextSnapshot($@"@custom
 {{
     <div>
-}}";
+}}");
             var syntaxTree = GetSyntaxTree(source, new[] { customDirective });
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 2),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(3),
                 indentSize: 4,
                 tabSize: 4);
 
@@ -106,21 +106,21 @@ namespace Microsoft.CodeAnalysis.Razor
         public void GetDesiredIndentation_ReturnsCorrectIndentation_ForNestedMarkupWithinCodeBlock()
         {
             // Arrange
-            var source = $@"
+            var source = new StringTextSnapshot($@"
 <div>
     @{{
         <span>
     }}
 </div>
-";
+");
             var syntaxTree = GetSyntaxTree(source);
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 3),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(4),
                 indentSize: 4,
                 tabSize: 4);
 
@@ -133,20 +133,20 @@ namespace Microsoft.CodeAnalysis.Razor
         {
             // Arrange
             var customDirective = DirectiveDescriptor.CreateRazorBlockDirective("custom");
-            var source = $@"@custom
+            var source = new StringTextSnapshot($@"@custom
 {{
     @{{
         <div>
     }}
-}}";
+}}");
             var syntaxTree = GetSyntaxTree(source, new[] { customDirective });
             var service = new DefaultRazorIndentationFactsService();
 
             // Act
             var indentation = service.GetDesiredIndentation(
                 syntaxTree,
-                previousLineEndIndex: GetLineEndIndexForLine(source, 3),
+                source,
-                getLineContent: line => GetLineContent(source, line),
+                source.GetLineFromLineNumber(4),
                 indentSize: 4,
                 tabSize: 4);
 
@@ -154,7 +154,7 @@ namespace Microsoft.CodeAnalysis.Razor
             Assert.Equal(8, indentation);
         }
 
-        private static RazorSyntaxTree GetSyntaxTree(string source, IEnumerable<DirectiveDescriptor> directives = null)
+        private static RazorSyntaxTree GetSyntaxTree(StringTextSnapshot source, IEnumerable<DirectiveDescriptor> directives = null)
         {
             directives = directives ?? Enumerable.Empty<DirectiveDescriptor>();
             var engine = RazorEngine.CreateDesignTime(builder =>
@@ -165,45 +165,12 @@ namespace Microsoft.CodeAnalysis.Razor
                 }
             });
 
-            var sourceDocument = RazorSourceDocument.Create(source, "test.cshtml");
+            var sourceDocument = RazorSourceDocument.Create(source.GetText(), "test.cshtml");
             var codeDocument = RazorCodeDocument.Create(sourceDocument);
 
             engine.Process(codeDocument);
 
             return codeDocument.GetSyntaxTree();
         }
-
-        private static string GetLineContent(string source, int lineIndex)
-        {
-            if (string.IsNullOrEmpty(source))
-            {
-                return string.Empty;
-            }
-
-            var lines = source.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
-            return lines[lineIndex];
-        }
-
-        private static int GetLineEndIndexForLine(string source, int lineIndex)
-        {
-            var absoluteIndex = 0;
-            if (string.IsNullOrEmpty(source))
-            {
-                return absoluteIndex; 
-            }
-
-            var lines = source.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
-            for (var i = 0; i <= lineIndex; i++)
-            {
-                absoluteIndex += lines[i].Length;
-
-                if (i < lineIndex)
-                {
-                    absoluteIndex += Environment.NewLine.Length;
-                }
-            }
-
-            return absoluteIndex;
-        }
     }
 }