Add out-of-scope Blazor Component completions with auto-insert @using statements

src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/Serialization/CompletionListSerializationBenchmark.cs

@@ -67,11 +67,12 @@ public void ComponentElement_CompletionList_Deserialization()
     private CompletionList GenerateCompletionList(string documentContent, int queryIndex, TagHelperCompletionProvider componentCompletionProvider)
     {
         var sourceDocument = RazorSourceDocument.Create(documentContent, RazorSourceDocumentProperties.Default);
+        var codeDocument = RazorCodeDocument.Create(sourceDocument);
         var syntaxTree = RazorSyntaxTree.Parse(sourceDocument);
         var tagHelperDocumentContext = TagHelperDocumentContext.Create(prefix: string.Empty, CommonResources.LegacyTagHelpers);
 
         var owner = syntaxTree.Root.FindInnermostNode(queryIndex, includeWhitespace: true, walkMarkersBack: true);
-        var context = new RazorCompletionContext(queryIndex, owner, syntaxTree, tagHelperDocumentContext);
+        var context = new RazorCompletionContext(codeDocument, queryIndex, owner, syntaxTree, tagHelperDocumentContext);
 
         var razorCompletionItems = componentCompletionProvider.GetCompletionItems(context);
         var completionList = RazorCompletionListProvider.CreateLSPCompletionList(

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/RazorCompletionContext.cs

@@ -8,6 +8,7 @@
 namespace Microsoft.CodeAnalysis.Razor.Completion;
 
 internal record RazorCompletionContext(
+    RazorCodeDocument CodeDocument,
     int AbsoluteIndex,
     RazorSyntaxNode? Owner,
     RazorSyntaxTree SyntaxTree,

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/RazorCompletionItem.cs

@@ -22,6 +22,7 @@ internal sealed class RazorCompletionItem
     public object DescriptionInfo { get; }
     public ImmutableArray<RazorCommitCharacter> CommitCharacters { get; }
     public bool IsSnippet { get; }
+    public TextEdit[]? AdditionalTextEdits { get; }
 
     /// <summary>
     /// Creates a new Razor completion item
@@ -33,6 +34,7 @@ internal sealed class RazorCompletionItem
     /// <param name="descriptionInfo">An object that provides description information for this completion item.</param>
     /// <param name="commitCharacters">Characters that can be used to commit the completion item.</param>
     /// <param name="isSnippet">Indicates whether the completion item's <see cref="InsertText"/> is an LSP snippet or not.</param>
+    /// <param name="additionalTextEdits">Additional text edits to apply when the completion is committed.</param>
     /// <exception cref="ArgumentNullException">Thrown if <paramref name="displayText"/> or <paramref name="insertText"/> are <see langword="null"/>.</exception>
     private RazorCompletionItem(
         RazorCompletionItemKind kind,
@@ -41,7 +43,8 @@ private RazorCompletionItem(
         string? sortText,
         object descriptionInfo,
         ImmutableArray<RazorCommitCharacter> commitCharacters,
-        bool isSnippet)
+        bool isSnippet,
+        TextEdit[]? additionalTextEdits = null)
     {
         ArgHelper.ThrowIfNull(displayText);
         ArgHelper.ThrowIfNull(insertText);
@@ -53,6 +56,7 @@ private RazorCompletionItem(
         DescriptionInfo = descriptionInfo;
         CommitCharacters = commitCharacters.NullToEmpty();
         IsSnippet = isSnippet;
+        AdditionalTextEdits = additionalTextEdits;
     }
 
     public static RazorCompletionItem CreateDirective(
@@ -82,8 +86,9 @@ public static RazorCompletionItem CreateMarkupTransition(
     public static RazorCompletionItem CreateTagHelperElement(
         string displayText, string insertText,
         AggregateBoundElementDescription descriptionInfo,
-        ImmutableArray<RazorCommitCharacter> commitCharacters)
-        => new(RazorCompletionItemKind.TagHelperElement, displayText, insertText, sortText: null, descriptionInfo, commitCharacters, isSnippet: false);
+        ImmutableArray<RazorCommitCharacter> commitCharacters,
+        TextEdit[]? additionalTextEdits = null)
+        => new(RazorCompletionItemKind.TagHelperElement, displayText, insertText, sortText: null, descriptionInfo, commitCharacters, isSnippet: false, additionalTextEdits);
 
     public static RazorCompletionItem CreateTagHelperAttribute(
         string displayText, string insertText, string? sortText,

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/RazorCompletionListProvider.cs

@@ -52,6 +52,7 @@ internal class RazorCompletionListProvider(
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
 
         var razorCompletionContext = new RazorCompletionContext(
+            codeDocument,
             absoluteIndex,
             owner,
             syntaxTree,
@@ -136,6 +137,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = razorCompletionItem.IsSnippet ? CompletionItemKind.Snippet : CompletionItemKind.Keyword,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     directiveCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -159,6 +161,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = tagHelperCompletionItemKind,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     directiveAttributeCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -176,6 +179,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = tagHelperCompletionItemKind,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     parameterCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -193,6 +197,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = CompletionItemKind.Event,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     eventValueCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -210,6 +215,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = tagHelperCompletionItemKind,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     markupTransitionCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -227,6 +233,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = tagHelperCompletionItemKind,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     tagHelperElementCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);
@@ -244,6 +251,7 @@ internal static bool TryConvert(
                         SortText = razorCompletionItem.SortText,
                         InsertTextFormat = insertTextFormat,
                         Kind = tagHelperCompletionItemKind,
+                        AdditionalTextEdits = razorCompletionItem.AdditionalTextEdits,
                     };
 
                     tagHelperAttributeCompletionItem.UseCommitCharactersFrom(razorCompletionItem, clientCapabilities);

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/TagHelperCompletionProvider.cs

@@ -10,6 +10,7 @@
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.Syntax;
 using Microsoft.AspNetCore.Razor.PooledObjects;
+using Microsoft.CodeAnalysis.Razor.Formatting;
 using Microsoft.CodeAnalysis.Razor.Tooltip;
 using Microsoft.VisualStudio.Editor.Razor;
 using RazorSyntaxNode = Microsoft.AspNetCore.Razor.Language.Syntax.SyntaxNode;
@@ -233,20 +234,48 @@ private ImmutableArray<RazorCompletionItem> GetElementCompletions(
 
         foreach (var (displayText, tagHelpers) in completionResult.Completions)
         {
-            var tagHelperDescriptions = tagHelpers.SelectAsArray(BoundElementDescriptionInfo.From);
+            var descriptionInfo = new AggregateBoundElementDescription(tagHelpers.SelectAsArray(BoundElementDescriptionInfo.From));
 
             var razorCompletionItem = RazorCompletionItem.CreateTagHelperElement(
                 displayText: displayText,
                 insertText: displayText,
-                descriptionInfo: new(tagHelperDescriptions),
+                descriptionInfo,
                 commitCharacters: commitChars);
 
             completionItems.Add(razorCompletionItem);
+            AddCompletionItemWithUsingDirective(ref completionItems.AsRef(), context, commitChars, displayText, descriptionInfo);
         }
 
         return completionItems.ToImmutableAndClear();
     }
 
+    private static void AddCompletionItemWithUsingDirective(ref PooledArrayBuilder<RazorCompletionItem> completionItems, RazorCompletionContext context, ImmutableArray<RazorCommitCharacter> commitChars, string displayText, AggregateBoundElementDescription descriptionInfo)
+    {
+        // If this is a fully qualified name (contains a dot), it means there's an out-of-scope component
+        // so we add an additional completion item with @using hint and additional edits that will insert
+        // the @using correctly.
+        var lastDotIndex = displayText.LastIndexOf('.');
+        if (lastDotIndex == -1)
+        {
+            return;
+        }
+
+        var @namespace = displayText[..lastDotIndex];
+        var shortName = displayText[(lastDotIndex + 1)..]; // Get the short name after the last dot
+        var displayTextWithUsing = $"{shortName} - @using {@namespace}";
+
+        var addUsingEdit = AddUsingsHelper.CreateAddUsingTextEdit(@namespace, context.CodeDocument);
+
+        var razorCompletionItemWithUsing = RazorCompletionItem.CreateTagHelperElement(
+            displayText: displayTextWithUsing,
+            insertText: shortName,
+            descriptionInfo,
+            commitCharacters: commitChars,
+            additionalTextEdits: [addUsingEdit]);
+
+        completionItems.Add(razorCompletionItemWithUsing);
+    }
+
     private const string BooleanTypeString = "System.Boolean";
 
     private static AttributeContext ResolveAttributeContext(

src/Razor/src/Microsoft.VisualStudio.LegacyEditor.Razor/Completion/RazorDirectiveAttributeCompletionSource.cs

@@ -78,7 +78,7 @@ public async Task<CompletionContext> GetCompletionContextAsync(IAsyncCompletionS
 #pragma warning disable CS0618 // Type or member is obsolete, will be removed in an upcoming change
             var owner = syntaxTree.Root.LocateOwner(queryableChange);
 #pragma warning restore CS0618 // Type or member is obsolete
-            var razorCompletionContext = new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperContext);
+            var razorCompletionContext = new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperContext);
             var razorCompletionItems = _completionFactsService.GetCompletionItems(razorCompletionContext);
 
             if (razorCompletionItems.Length == 0)

src/Razor/src/Microsoft.VisualStudio.LegacyEditor.Razor/Completion/RazorDirectiveCompletionSource.cs

@@ -80,7 +80,7 @@ public async Task<CompletionContext> GetCompletionContextAsync(
 #pragma warning disable CS0618 // Type or member is obsolete, will be removed in an upcoming change
             var owner = syntaxTree.Root.LocateOwner(queryableChange);
 #pragma warning restore CS0618 // Type or member is obsolete
-            var razorCompletionContext = new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperContext);
+            var razorCompletionContext = new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperContext);
             var razorCompletionItems = _completionFactsService.GetCompletionItems(razorCompletionContext);
 
             using var _ = ArrayBuilderPool<CompletionItem>.GetPooledObject(out var completionItems);

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/TagHelperCompletionProviderTest.cs

@@ -942,6 +942,6 @@ private static RazorCompletionContext CreateRazorCompletionContext(string markup
 
         var owner = syntaxTree.Root.FindInnermostNode(position, includeWhitespace: true, walkMarkersBack: true);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, position);
-        return new RazorCompletionContext(position, owner, syntaxTree, context, Options: options);
+        return new RazorCompletionContext(codeDocument, position, owner, syntaxTree, context, Options: options);
     }
 }

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DefaultRazorCompletionFactsServiceTest.cs

@@ -15,6 +15,8 @@ public class DefaultRazorCompletionFactsServiceTest(ITestOutputHelper testOutput
     public void GetDirectiveCompletionItems_AllProvidersCompletionItems()
     {
         // Arrange
+        var sourceDocument = RazorSourceDocument.Create("", RazorSourceDocumentProperties.Default);
+        var codeDocument = RazorCodeDocument.Create(sourceDocument);
         var syntaxTree = RazorSyntaxTree.Parse(TestRazorSourceDocument.Create());
         var tagHelperDocumentContext = TagHelperDocumentContext.Create(prefix: null, tagHelpers: []);
 
@@ -26,7 +28,7 @@ public void GetDirectiveCompletionItems_AllProvidersCompletionItems()
             commitCharacters: [],
             isSnippet: false);
 
-        var context = new RazorCompletionContext(AbsoluteIndex: 0, Owner: null, syntaxTree, tagHelperDocumentContext);
+        var context = new RazorCompletionContext(codeDocument, AbsoluteIndex: 0, Owner: null, SyntaxTree: syntaxTree, TagHelperDocumentContext: tagHelperDocumentContext);
         var provider1 = StrictMock.Of<IRazorCompletionItemProvider>(p =>
             p.GetCompletionItems(context) == ImmutableArray.Create(completionItem1));
 

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DirectiveAttributeCompletionItemProviderTest.cs

@@ -363,7 +363,7 @@ private RazorCompletionContext CreateRazorCompletionContext(TestCode testCode)
         var owner = syntaxTree.Root.FindInnermostNode(testCode.Position, includeWhitespace: true, walkMarkersBack: true);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, testCode.Position);
 
-        return new RazorCompletionContext(testCode.Position, owner, syntaxTree, tagHelperContext);
+        return new RazorCompletionContext(codeDocument, testCode.Position, owner, syntaxTree, tagHelperContext);
     }
 
     private RazorSyntaxNode GetOwner(string testCodeText)

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DirectiveAttributeEventParameterCompletionItemProviderTest.cs

@@ -211,6 +211,6 @@ private RazorCompletionContext CreateRazorCompletionContext(TestCode documentCon
 
         var owner = syntaxTree.Root.FindInnermostNode(absoluteIndex);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
-        return new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperDocumentContext);
+        return new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperDocumentContext);
     }
 }

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DirectiveAttributeParameterCompletionItemProviderTest.cs

@@ -178,6 +178,6 @@ private RazorCompletionContext CreateRazorCompletionContext(int absoluteIndex, s
 
         var owner = syntaxTree.Root.FindInnermostNode(absoluteIndex);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
-        return new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperContext);
+        return new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperContext);
     }
 }

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DirectiveAttributeTransitionCompletionItemProviderTest.cs

@@ -327,7 +327,7 @@ public void GetCompletionItems_WithAvoidExplicitCommitOption_ReturnsAppropriateC
         }
     }
 
-    private static RazorSyntaxTree GetSyntaxTree(string text, RazorFileKind? fileKind = null)
+    private static RazorCodeDocument GetCodeDocument(string text, RazorFileKind? fileKind = null)
     {
         var fileKindValue = fileKind ?? RazorFileKind.Component;
 
@@ -340,17 +340,16 @@ private static RazorSyntaxTree GetSyntaxTree(string text, RazorFileKind? fileKin
             });
         });
 
-        var codeDocument = projectEngine.Process(sourceDocument, fileKindValue, importSources: default, tagHelpers: []);
-
-        return codeDocument.GetRequiredSyntaxTree();
+        return projectEngine.Process(sourceDocument, fileKindValue, importSources: default, tagHelpers: []);
     }
 
     private RazorCompletionContext CreateContext(int absoluteIndex, string documentContent, RazorFileKind? fileKind = null)
     {
-        var syntaxTree = GetSyntaxTree(documentContent, fileKind);
+        var codeDocument = GetCodeDocument(documentContent, fileKind);
+        var syntaxTree = codeDocument.GetRequiredSyntaxTree();
         var owner = syntaxTree.Root.FindInnermostNode(absoluteIndex, includeWhitespace: true, walkMarkersBack: true);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
 
-        return new RazorCompletionContext(absoluteIndex, owner, syntaxTree, _tagHelperDocumentContext);
+        return new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, _tagHelperDocumentContext);
     }
 }

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/DirectiveCompletionItemProviderTest.cs

@@ -430,10 +430,13 @@ public void IsDirectiveCompletableToken_ReturnsFalseForInvalidCSharpTokens()
 
     private static RazorCompletionContext CreateRazorCompletionContext(int absoluteIndex, RazorSyntaxTree syntaxTree, CompletionReason reason = CompletionReason.Invoked)
     {
+        var sourceDocument = RazorSourceDocument.Create("", RazorSourceDocumentProperties.Default);
+        var codeDocument = RazorCodeDocument.Create(sourceDocument);
+
         var tagHelperDocumentContext = TagHelperDocumentContext.Create(prefix: string.Empty, tagHelpers: []);
         var owner = syntaxTree.Root.FindInnermostNode(absoluteIndex);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
-        return new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperDocumentContext, reason);
+        return new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperDocumentContext, reason);
     }
 
     private static void AssertRazorCompletionItem(string completionDisplayText, DirectiveDescriptor directive, RazorCompletionItem item, ImmutableArray<RazorCommitCharacter> commitCharacters = default, bool isSnippet = false)

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/MarkupTransitionCompletionItemProviderTest.cs

@@ -326,11 +326,14 @@ private static void AssertRazorCompletionItem(RazorCompletionItem item)
 
     private static RazorCompletionContext CreateRazorCompletionContext(int absoluteIndex, RazorSyntaxTree syntaxTree)
     {
+        var sourceDocument = RazorSourceDocument.Create("", RazorSourceDocumentProperties.Default);
+        var codeDocument = RazorCodeDocument.Create(sourceDocument);
+
         var tagHelperDocumentContext = TagHelperDocumentContext.Create(prefix: string.Empty, tagHelpers: []);
 
         var owner = syntaxTree.Root.FindInnermostNode(absoluteIndex, includeWhitespace: true, walkMarkersBack: true);
         owner = AbstractRazorCompletionFactsService.AdjustSyntaxNodeForWordBoundary(owner, absoluteIndex);
-        return new RazorCompletionContext(absoluteIndex, owner, syntaxTree, tagHelperDocumentContext);
+        return new RazorCompletionContext(codeDocument, absoluteIndex, owner, syntaxTree, tagHelperDocumentContext);
     }
 
     private static RazorSyntaxTree CreateSyntaxTree(string text, params DirectiveDescriptor[] directives)