Improve tooltips on hover.

CHANGELOG.md

@@ -2,7 +2,8 @@
 
 ## v0.1.1
 
-* Use a patched version of `Microsoft.Language.Xml` that behaves correctly in non-windows environments.
+* Use a patched version of `Microsoft.Language.Xml` that behaves correctly in non-windows environments (issues with CR vs CRLF line-endings).
+* Improve tooltips on hover.
 
 ## v0.1.0
 

src/LanguageServer.Engine/Handlers/HoverContent.cs

@@ -0,0 +1,256 @@
+using Lsp.Models;
+using Microsoft.Language.Xml;
+using System;
+using System.IO;
+using System.Text;
+using System.Linq;
+
+namespace MSBuildProjectTools.LanguageServer.Handlers
+{
+    using MSBuild;
+    using Documents;
+    using Utilities;
+
+    /// <summary>
+    ///     Content for tooltips when hovering over nodes in the MSBuild XML.
+    /// </summary>
+    public static class HoverContent
+    {
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildProperty"/>.
+        /// </summary>
+        /// <param name="property">
+        ///     The <see cref="MSBuildProperty"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer Property(MSBuildProperty property)
+        {
+            if (property == null)
+                throw new ArgumentNullException(nameof(property));
+
+            if (property.IsOverridden)
+            {
+                Position overridingDeclarationPosition = property.DeclaringXml.Location.ToNative();
+
+                StringBuilder overrideDescription = new StringBuilder();
+                string declarationFile = property.DeclaringXml.Location.File;
+                if (declarationFile != property.Property.Xml.Location.File)
+                {
+                    Uri declarationDocumentUri = UriHelper.CreateDocumentUri(declarationFile);
+                    overrideDescription.AppendLine(
+                        $"Value overridden at {overridingDeclarationPosition} in [{Path.GetFileName(declarationFile)}]({declarationDocumentUri})."
+                    );
+                }
+                else
+                    overrideDescription.AppendLine($"Value overridden at {overridingDeclarationPosition} in this file.");
+
+                overrideDescription.AppendLine();
+                overrideDescription.AppendLine();
+                overrideDescription.AppendLine(
+                    $"Unused value: `{property.DeclaringXml.Value}`"
+                );
+                overrideDescription.AppendLine();
+                overrideDescription.AppendLine(
+                    $"Actual value: `{property.Value}`"
+                );
+
+                return new MarkedStringContainer(
+                    $"Property: `{property.Name}`",
+                    overrideDescription.ToString()
+                );
+            }
+
+            return new MarkedStringContainer(
+                $"Property: `{property.Name}`",
+                $"Value: `{property.Value}`"
+            );
+        }
+
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildUnusedProperty"/>.
+        /// </summary>
+        /// <param name="undefinedProperty">
+        ///     The <see cref="MSBuildUnusedProperty"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer UnusedProperty(MSBuildUnusedProperty undefinedProperty, ProjectDocument projectDocument)
+        {
+            if (undefinedProperty == null)
+                throw new ArgumentNullException(nameof(undefinedProperty));
+
+            string condition = undefinedProperty.PropertyElement.Condition;
+            if (String.IsNullOrWhiteSpace(condition))
+                condition = undefinedProperty.PropertyElement.Parent.Condition; // Condition may be on parent element.
+
+            string expandedCondition = projectDocument.MSBuildProject.ExpandString(condition);
+
+            return new MarkedStringContainer(
+                $"Property: `{undefinedProperty.Name}` (condition evaluates to false)",
+                $"Unused value:\n* `{undefinedProperty.Value}`\n\nCondition:\n* Raw =`{condition}`\n* Evaluated = `{expandedCondition}`"
+            );
+        }
+
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildItemGroup"/>.
+        /// </summary>
+        /// <param name="itemGroup">
+        ///     The <see cref="MSBuildItemGroup"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer ItemGroup(MSBuildItemGroup itemGroup)
+        {
+            if (itemGroup == null)
+                throw new ArgumentNullException(nameof(itemGroup));
+
+            if (itemGroup.Name == "PackageReference")
+            {
+                string packageVersion = itemGroup.GetFirstMetadataValue("Version");
+
+                return new MarkedStringContainer(
+                    $"NuGet Package: `{itemGroup.FirstInclude}`",
+                    $"Version: {packageVersion}"
+                );
+            }
+
+            string[] includes = itemGroup.Includes.ToArray();
+            StringBuilder itemIncludeContent = new StringBuilder();
+            itemIncludeContent.AppendLine(
+                $"Include: `{itemGroup.OriginatingElement.Include}`  "
+            );
+            itemIncludeContent.AppendLine();
+            itemIncludeContent.Append(
+                $"Evaluates to {itemGroup.Items.Count} item"
+            );
+            if (!itemGroup.HasSingleItem)
+                itemIncludeContent.Append("s");
+            itemIncludeContent.AppendLine(".");
+
+            foreach (string include in includes.Take(5))
+            {
+                // TODO: Consider making hyperlinks for includes that map to files which exist.
+                itemIncludeContent.AppendLine(
+                    $"* `{include}`"
+                );
+            }
+            if (includes.Length > 5)
+                itemIncludeContent.AppendLine("* ...");
+
+            return new MarkedStringContainer(
+                $"Items Group: `{itemGroup.OriginatingElement.ItemType}`",
+                itemIncludeContent.ToString()
+            );  
+        }
+
+        /// <summary>
+        ///     Get hover content for an attribute of an <see cref="MSBuildItemGroup"/>.
+        /// </summary>
+        /// <param name="itemGroup">
+        ///     The <see cref="MSBuildItemGroup"/>.
+        /// </param>
+        /// <param name="attribute">
+        ///     The attribute.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer ItemGroup(MSBuildItemGroup itemGroup, XmlAttributeSyntax attribute)
+        {
+            if (itemGroup == null)
+                throw new ArgumentNullException(nameof(itemGroup));
+
+            if (itemGroup.Name == "PackageReference")
+                return ItemGroup(itemGroup);
+
+            // TODO: Handle the "Condition" attribute.
+            if (attribute.Name == "Condition")
+                return null;
+
+            string metadataName = attribute.Name;
+            if (String.Equals(metadataName, "Include"))
+                metadataName = "Identity";
+
+            StringBuilder metadataValues = new StringBuilder();
+            metadataValues.AppendLine("Values:");
+
+            foreach (string metadataValue in itemGroup.GetMetadataValues(metadataName).Distinct())
+            {
+                metadataValues.AppendLine(
+                    $"* `{metadataValue}`"
+                );
+            }
+
+            return new MarkedStringContainer(
+                $"Item Metadata: `{itemGroup.Name}.{metadataName}`",
+                metadataValues.ToString()
+            );
+        }
+
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildTarget"/>.
+        /// </summary>
+        /// <param name="target">
+        ///     The <see cref="MSBuildTarget"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer Target(MSBuildTarget target)
+        {
+            if (target == null)
+                throw new ArgumentNullException(nameof(target));
+
+            return $"Target: `{target.Name}`";
+        }
+
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildImport"/>.
+        /// </summary>
+        /// <param name="import">
+        ///     The <see cref="MSBuildImport"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer Import(MSBuildImport import)
+        {
+            if (import == null)
+                throw new ArgumentNullException(nameof(import));
+
+            string importedProject = import.ProjectImportElement.Project;
+            Uri projectFileUri = UriHelper.CreateDocumentUri(import.ImportedProjectRoot.Location.File);
+
+            return $"Import: [{importedProject}]({projectFileUri})";
+        }
+
+        /// <summary>
+        ///     Get hover content for an <see cref="MSBuildSdkImport"/>.
+        /// </summary>
+        /// <param name="sdkImport">
+        ///     The <see cref="MSBuildSdkImport"/>.
+        /// </param>
+        /// <returns>
+        ///     The content.
+        /// </returns>
+        public static MarkedStringContainer SdkImport(MSBuildSdkImport sdkImport)
+        {
+            if (sdkImport == null)
+                throw new ArgumentNullException(nameof(sdkImport));
+
+            StringBuilder imports = new StringBuilder("Imports:");
+            imports.AppendLine();
+            foreach (string projectFile in sdkImport.ImportedProjectFiles)
+                imports.AppendLine($"* [{Path.GetFileName(projectFile)}]({UriHelper.CreateDocumentUri(projectFile)})");
+
+            return new MarkedStringContainer(
+                $"SDK Import: {sdkImport.Name}",
+                imports.ToString()
+            );
+        }
+    }
+}