Fixed snippet behaviour in the middle of an attribute

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Completion/TagHelperCompletionProvider.cs

@@ -180,7 +180,10 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Completion
                 var attributeCommitCharacters = ResolveAttributeCommitCharacters(attributeContext);
                 var isSnippet = false;
                 var insertText = filterText;
-                if (TryResolveInsertText(insertText, attributeContext, out var snippetText))
+
+                // Do not turn attributes into snippets if we are in an already written full attribute (https://github.com/dotnet/razor-tooling/issues/6724)
+                if (containingAttribute is not (MarkupTagHelperAttributeSyntax or MarkupAttributeBlockSyntax) &&
+                    TryResolveInsertText(insertText, attributeContext, out var snippetText))
                 {
                     isSnippet = true;
                     insertText = snippetText;
@@ -293,19 +296,14 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Completion
 
         private static IReadOnlyList<RazorCommitCharacter> ResolveAttributeCommitCharacters(AttributeContext attributeContext)
         {
-            switch (attributeContext)
+            return attributeContext switch
             {
-                case AttributeContext.Indexer:
-                    return s_noCommitCharacters;
-                case AttributeContext.Minimized:
-                    return MinimizedAttributeCommitCharacters;
-                case AttributeContext.Full:
-                    return AttributeCommitCharacters;
-                case AttributeContext.FullSnippet:
-                    return AttributeSnippetCommitCharacters;
-                default:
-                    throw new InvalidOperationException("Unexpected context");
-            }
+                AttributeContext.Indexer => s_noCommitCharacters,
+                AttributeContext.Minimized => MinimizedAttributeCommitCharacters,
+                AttributeContext.Full => AttributeCommitCharacters,
+                AttributeContext.FullSnippet => AttributeSnippetCommitCharacters,
+                _ => throw new InvalidOperationException("Unexpected context"),
+            };
         }
 
         private enum AttributeContext

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

@@ -545,6 +545,33 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Completion
             AssertBoolIntCompletions(completions);
         }
 
+        [Fact]
+        [WorkItem("https://github.com/dotnet/razor-tooling/issues/6724")]
+        public void GetCompletionsAt_MiddleOfFullAttribute_ReturnsCompletions_NoSnippetBehaviour()
+        {
+            // Arrange
+            var service = new TagHelperCompletionProvider(RazorTagHelperCompletionService, HtmlFactsService, TagHelperFactsService);
+            var txt = $"@addTagHelper *, TestAssembly{Environment.NewLine}<test2 int-val=''>";
+            var context = CreateRazorCompletionContext(absoluteIndex: 40 + Environment.NewLine.Length, txt, options: new(SnippetsSupported: true), isRazorFile: false, tagHelpers: DefaultTagHelpers);
+
+            // Act
+            var completions = service.GetCompletionItems(context);
+
+            // Assert
+            Assert.Collection(completions,
+                completion =>
+                {
+                    Assert.Equal("bool-val", completion.InsertText); // bool-val will be filtered on IDE side anyway, so just check that it exists and then don't care about it properties
+                },
+                completion =>
+                {
+                    Assert.Equal("int-val", completion.InsertText);
+                    Assert.False(completion.IsSnippet);
+                    Assert.Equal(TagHelperCompletionProvider.AttributeSnippetCommitCharacters, completion.CommitCharacters); // we still want `=` to be a commit character, but we don't want it to be inserted
+                }
+            );
+        }
+
         private static void AssertBoolIntCompletions(IReadOnlyList<RazorCompletionItem> completions)
         {
             Assert.Collection(completions,