Introduces a new hover provider, under V2 of the protocol, that uses Roslyn's QuickInfoService

.pipelines/init.yml

@@ -1,7 +1,7 @@
 parameters:
   # Configuration: Release
   Verbosity: Normal
-  DotNetVersion: "3.1.201"
+  DotNetVersion: "3.1.302"
   CakeVersion: "0.32.1"
   NuGetVersion: "4.9.2"
 steps:

azure-pipelines.yml

@@ -22,7 +22,7 @@ resources:
 
 variables:
   Verbosity: Diagnostic
-  DotNetVersion: "3.1.201"
+  DotNetVersion: "3.1.302"
   CakeVersion: "0.32.1"
   NuGetVersion: "4.9.2"
   GitVersionVersion: "5.0.1"

build.json

@@ -2,7 +2,7 @@
     "DotNetInstallScriptURL": "https://dot.net/v1",
     "DotNetChannel": "Preview",
     "DotNetVersions": [
-        "3.1.201",
+        "3.1.302",
         "5.0.100-preview.7.20366.6"
     ],
     "RequiredMonoVersion": "6.6.0",

global.json

@@ -1,5 +1,5 @@
 {
     "sdk": {
-        "version": "3.1.201"
+        "version": "3.1.302"
     }
 }

src/OmniSharp.Abstractions/Models/v1/QuickInfoRequest.cs

@@ -0,0 +1,9 @@
+using OmniSharp.Mef;
+
+namespace OmniSharp.Models
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.QuickInfo, typeof(QuickInfoRequest), typeof(QuickInfoResponse))]
+    public class QuickInfoRequest : Request
+    {
+    }
+}

src/OmniSharp.Abstractions/Models/v1/QuickInfoResponse.cs

@@ -0,0 +1,13 @@
+#nullable enable
+using System.Collections.Immutable;
+
+namespace OmniSharp.Models
+{
+    public class QuickInfoResponse
+    {
+        /// <summary>
+        /// QuickInfo for the given position, rendered as markdown.
+        /// </summary>
+        public string Markdown { get; set; } = string.Empty;
+    }
+}

src/OmniSharp.Abstractions/OmniSharpEndpoints.cs

@@ -44,6 +44,7 @@ public static class OmniSharpEndpoints
         public const string Diagnostics = "/diagnostics";
 
         public const string ReAnalyze = "/reanalyze";
+        public const string QuickInfo = "/quickinfo";
 
         public static class V2
         {
@@ -65,6 +66,7 @@ public static class V2
             public const string CodeStructure = "/v2/codestructure";
 
             public const string Highlight = "/v2/highlight";
+
         }
     }
 }

src/OmniSharp.Roslyn.CSharp/Services/QuickInfoProvider.cs

@@ -0,0 +1,275 @@
+using System.Composition;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.QuickInfo;
+using Microsoft.CodeAnalysis.Text;
+using Microsoft.Extensions.Logging;
+using OmniSharp.Mef;
+using OmniSharp.Models;
+using OmniSharp.Options;
+
+#nullable enable
+
+namespace OmniSharp.Roslyn.CSharp.Services
+{
+    [OmniSharpHandler(OmniSharpEndpoints.QuickInfo, LanguageNames.CSharp)]
+    public class QuickInfoProvider : IRequestHandler<QuickInfoRequest, QuickInfoResponse>
+    {
+        // Based on https://github.com/dotnet/roslyn/blob/7dc32a952e77c96c31cae6a2ba6d253a558fc7ff/src/Features/LanguageServer/Protocol/Handler/Hover/HoverHandler.cs
+
+        // These are internal tag values taken from https://github.com/dotnet/roslyn/blob/master/src/Features/Core/Portable/Common/TextTags.cs
+        // They're copied here so that we can ensure we render blocks correctly in the markdown
+        // https://github.com/dotnet/roslyn/issues/46254 tracks making these public
+
+        /// <summary>
+        /// Indicates the start of a text container. The elements after <see cref="ContainerStart"/> through (but not
+        /// including) the matching <see cref="ContainerEnd"/> are rendered in a rectangular block which is positioned
+        /// as an inline element relative to surrounding elements. The text of the <see cref="ContainerStart"/> element
+        /// itself precedes the content of the container, and is typically a bullet or number header for an item in a
+        /// list.
+        /// </summary>
+        private const string ContainerStart = nameof(ContainerStart);
+        /// <summary>
+        /// Indicates the end of a text container. See <see cref="ContainerStart"/>.
+        /// </summary>
+        private const string ContainerEnd = nameof(ContainerEnd);
+        /// <summary>
+        /// Section kind for nullability analysis.
+        /// </summary>
+        internal const string NullabilityAnalysis = nameof(NullabilityAnalysis);
+
+        private readonly OmniSharpWorkspace _workspace;
+        private readonly FormattingOptions _formattingOptions;
+        private readonly ILogger<QuickInfoProvider>? _logger;
+
+        [ImportingConstructor]
+        public QuickInfoProvider(OmniSharpWorkspace workspace, FormattingOptions formattingOptions, ILoggerFactory? loggerFactory)
+        {
+            _workspace = workspace;
+            _formattingOptions = formattingOptions;
+            _logger = loggerFactory?.CreateLogger<QuickInfoProvider>();
+        }
+
+        public async Task<QuickInfoResponse> Handle(QuickInfoRequest request)
+        {
+            var document = _workspace.GetDocument(request.FileName);
+            var response = new QuickInfoResponse();
+
+            if (document is null)
+            {
+                return response;
+            }
+
+            var quickInfoService = QuickInfoService.GetService(document);
+            if (quickInfoService is null)
+            {
+                _logger?.LogWarning($"QuickInfo service was null for {document.FilePath}");
+                return response;
+            }
+
+            var sourceText = await document.GetTextAsync();
+            var position = sourceText.Lines.GetPosition(new LinePosition(request.Line, request.Column));
+
+            var quickInfo = await quickInfoService.GetQuickInfoAsync(document, position);
+            if (quickInfo is null)
+            {
+                _logger?.LogTrace($"No QuickInfo found for {document.FilePath}:{request.Line},{request.Column}");
+                return response;
+            }
+
+            var finalTextBuilder = new StringBuilder();
+            var sectionTextBuilder = new StringBuilder();
+
+            var description = quickInfo.Sections.FirstOrDefault(s => s.Kind == QuickInfoSectionKinds.Description);
+            if (description is object)
+            {
+                appendSectionAsCsharp(description, finalTextBuilder, _formattingOptions, includeSpaceAtStart: false);
+            }
+
+            var summary = quickInfo.Sections.FirstOrDefault(s => s.Kind == QuickInfoSectionKinds.DocumentationComments);
+            if (summary is object)
+            {
+                buildSectionAsMarkdown(summary, sectionTextBuilder, _formattingOptions, out _);
+                appendBuiltSection(finalTextBuilder, sectionTextBuilder, _formattingOptions);
+            }
+
+            foreach (var section in quickInfo.Sections)
+            {
+                switch (section.Kind)
+                {
+                    case QuickInfoSectionKinds.Description:
+                    case QuickInfoSectionKinds.DocumentationComments:
+                        continue;
+
+                    case QuickInfoSectionKinds.TypeParameters:
+                        appendSectionAsCsharp(section, finalTextBuilder, _formattingOptions);
+                        break;
+
+                    case QuickInfoSectionKinds.AnonymousTypes:
+                        // The first line is "Anonymous Types:"
+                        buildSectionAsMarkdown(section, sectionTextBuilder, _formattingOptions, out int lastIndex, untilLineBreak: true);
+                        appendBuiltSection(finalTextBuilder, sectionTextBuilder, _formattingOptions);
+
+                        // Then we want all anonymous types to be C# highlighted
+                        appendSectionAsCsharp(section, finalTextBuilder, _formattingOptions, lastIndex + 1);
+                        break;
+
+                    case NullabilityAnalysis:
+                        // Italicize the nullable analysis for emphasis.
+                        buildSectionAsMarkdown(section, sectionTextBuilder, _formattingOptions, out _);
+                        appendBuiltSection(finalTextBuilder, sectionTextBuilder, _formattingOptions, italicize: true);
+                        break;
+
+                    default:
+                        buildSectionAsMarkdown(section, sectionTextBuilder, _formattingOptions, out _);
+                        appendBuiltSection(finalTextBuilder, sectionTextBuilder, _formattingOptions);
+                        break;
+                }
+            }
+
+            response.Markdown = finalTextBuilder.ToString().Trim();
+
+            return response;
+
+            static void appendBuiltSection(StringBuilder finalTextBuilder, StringBuilder stringBuilder, FormattingOptions formattingOptions, bool italicize = false)
+            {
+                // Two newlines to trigger a markdown new paragraph
+                finalTextBuilder.Append(formattingOptions.NewLine);
+                finalTextBuilder.Append(formattingOptions.NewLine);
+                if (italicize)
+                {
+                    finalTextBuilder.Append("_");
+                }
+                finalTextBuilder.Append(stringBuilder);
+                if (italicize)
+                {
+                    finalTextBuilder.Append("_");
+                }
+                stringBuilder.Clear();
+            }
+
+            static void appendSectionAsCsharp(QuickInfoSection section, StringBuilder builder, FormattingOptions formattingOptions, int startingIndex = 0, bool includeSpaceAtStart = true)
+            {
+                if (includeSpaceAtStart)
+                {
+                    builder.Append(formattingOptions.NewLine);
+                }
+                builder.Append("```csharp");
+                builder.Append(formattingOptions.NewLine);
+                for (int i = startingIndex; i < section.TaggedParts.Length; i++)
+                {
+                    TaggedText part = section.TaggedParts[i];
+                    if (part.Tag == TextTags.LineBreak && i + 1 != section.TaggedParts.Length)
+                    {
+                        builder.Append(formattingOptions.NewLine);
+                    }
+                    else
+                    {
+                        builder.Append(part.Text);
+                    }
+                }
+                builder.Append(formattingOptions.NewLine);
+                builder.Append("```");
+            }
+
+            static void buildSectionAsMarkdown(QuickInfoSection section, StringBuilder stringBuilder, FormattingOptions formattingOptions, out int lastIndex, bool untilLineBreak = false)
+            {
+                bool isInCodeBlock = false;
+                lastIndex = 0;
+                for (int i = 0; i < section.TaggedParts.Length; i++)
+                {
+                    var current = section.TaggedParts[i];
+                    lastIndex = i;
+
+                    switch (current.Tag)
+                    {
+                        case TextTags.Text when !isInCodeBlock:
+                            stringBuilder.Append(current.Text);
+                            break;
+
+                        case TextTags.Text:
+                            endBlock();
+                            stringBuilder.Append(current.Text);
+                            break;
+
+                        case TextTags.Space when isInCodeBlock:
+                            if (nextIsTag(i, TextTags.Text))
+                            {
+                                endBlock();
+                            }
+
+                            stringBuilder.Append(current.Text);
+                            break;
+
+                        case TextTags.Space:
+                        case TextTags.Punctuation:
+                            stringBuilder.Append(current.Text);
+                            break;
+
+                        case ContainerStart:
+                            addNewline();
+                            stringBuilder.Append(current.Text);
+                            break;
+
+                        case ContainerEnd:
+                            addNewline();
+                            break;
+
+                        case TextTags.LineBreak when untilLineBreak && stringBuilder.Length != 0:
+                            // The section will end and another newline will be appended, no need to add yet another newline.
+                            return;
+
+                        case TextTags.LineBreak:
+                            if (stringBuilder.Length != 0 && !nextIsTag(i, ContainerStart, ContainerEnd) && i + 1 != section.TaggedParts.Length)
+                            {
+                                addNewline();
+                            }
+                            break;
+
+                        default:
+                            if (!isInCodeBlock)
+                            {
+                                isInCodeBlock = true;
+                                stringBuilder.Append('`');
+                            }
+                            stringBuilder.Append(current.Text);
+                            break;
+                    }
+                }
+
+                if (isInCodeBlock)
+                {
+                    endBlock();
+                }
+
+                return;
+
+                void addNewline()
+                {
+                    if (isInCodeBlock)
+                    {
+                        endBlock();
+                    }
+
+                    // Markdown needs 2 linebreaks to make a new paragraph
+                    stringBuilder.Append(formattingOptions.NewLine);
+                    stringBuilder.Append(formattingOptions.NewLine);
+                }
+
+                void endBlock()
+                {
+                    stringBuilder.Append('`');
+                    isInCodeBlock = false;
+                }
+
+                bool nextIsTag(int i, params string[] tags)
+                {
+                    int nextI = i + 1;
+                    return nextI < section.TaggedParts.Length && tags.Contains(section.TaggedParts[nextI].Tag);
+                }
+            }
+        }
+    }
+}

test-assets/test-projects/global.json

@@ -1,5 +1,5 @@
 {
     "sdk": {
-        "version": "3.1.201"
+        "version": "3.1.302"
     }
 }

tests/OmniSharp.MSBuild.Tests/ProjectLoadListenerTests.cs

@@ -224,7 +224,7 @@ public async Task The_correct_sdk_version_is_emitted()
             using (var host = CreateMSBuildTestHost(testProject.Directory, emitter.AsExportDescriptionProvider(LoggerFactory)))
             {
                 Assert.Single(emitter.ReceivedMessages);
-                Assert.Equal(GetHashedFileExtension("3.1.201"), emitter.ReceivedMessages[0].SdkVersion);
+                Assert.Equal(GetHashedFileExtension("3.1.302"), emitter.ReceivedMessages[0].SdkVersion);
             }
         }