Add snippet support for component completion with EditorRequired attributes

.github/workflows/copilot-setup-steps.yml

@@ -40,6 +40,11 @@ jobs:
         # Use restore script, but don't fail on errors so Copilot can still attempt to work
         run: ./restore.sh
 
+      # Activate the private .NET install. Hopefully this resolves firewall issues when using dotnet build/test
+      - name: Activate
+        continue-on-error: true
+        run: source ./activate.sh
+
       # Diagnostics in the log
       - name: Show .NET info
         run: dotnet --info

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

@@ -87,8 +87,9 @@ public static RazorCompletionItem CreateTagHelperElement(
         string displayText, string insertText,
         AggregateBoundElementDescription descriptionInfo,
         ImmutableArray<RazorCommitCharacter> commitCharacters,
+        bool isSnippet = false,
         TextEdit[]? additionalTextEdits = null)
-        => new(RazorCompletionItemKind.TagHelperElement, displayText, insertText, sortText: null, descriptionInfo, commitCharacters, isSnippet: false, additionalTextEdits);
+        => new(RazorCompletionItemKind.TagHelperElement, displayText, insertText, sortText: null, descriptionInfo, commitCharacters, isSnippet, additionalTextEdits);
 
     public static RazorCompletionItem CreateTagHelperAttribute(
         string displayText, string insertText, string? sortText,

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

@@ -231,13 +231,24 @@ private ImmutableArray<RazorCompletionItem> GetElementCompletions(
         {
             var descriptionInfo = new AggregateBoundElementDescription(tagHelpers.SelectAsArray(BoundElementDescriptionInfo.From));
 
+            // Always add the regular completion item
             var razorCompletionItem = RazorCompletionItem.CreateTagHelperElement(
                 displayText: displayText,
                 insertText: displayText,
                 descriptionInfo,
-                commitCharacters: commitChars);
+                commitCharacters: commitChars,
+                isSnippet: false);
 
             completionItems.Add(razorCompletionItem);
+
+            AddCompletionItemWithRequiredAttributesSnippet(
+                ref completionItems.AsRef(),
+                context,
+                tagHelpers,
+                displayText,
+                descriptionInfo,
+                commitChars);
+
             AddCompletionItemWithUsingDirective(ref completionItems.AsRef(), context, commitChars, displayText, descriptionInfo);
         }
 
@@ -307,6 +318,79 @@ private static ImmutableArray<RazorCommitCharacter> ResolveAttributeCommitCharac
         };
     }
 
+    private static void AddCompletionItemWithRequiredAttributesSnippet(
+        ref PooledArrayBuilder<RazorCompletionItem> completionItems,
+        RazorCompletionContext context,
+        IEnumerable<TagHelperDescriptor> tagHelpers,
+        string displayText,
+        AggregateBoundElementDescription descriptionInfo,
+        ImmutableArray<RazorCommitCharacter> commitChars)
+    {
+        // If snippets are not supported, exit early
+        if (!context.Options.SnippetsSupported)
+        {
+            return;
+        }
+
+        if (TryGetEditorRequiredAttributesSnippet(tagHelpers, displayText, out var snippetText))
+        {
+            var snippetCompletionItem = RazorCompletionItem.CreateTagHelperElement(
+                displayText: SR.FormatComponentCompletionWithRequiredAttributesLabel(displayText),
+                insertText: snippetText,
+                descriptionInfo: descriptionInfo,
+                commitCharacters: commitChars,
+                isSnippet: true);
+
+            completionItems.Add(snippetCompletionItem);
+        }
+    }
+
+    private static bool TryGetEditorRequiredAttributesSnippet(
+        IEnumerable<TagHelperDescriptor> tagHelpers,
+        string tagName,
+        [NotNullWhen(true)] out string? snippetText)
+    {
+        // For components, there should only be one tag helper descriptor per component name
+        // Get EditorRequired attributes from the first component tag helper
+        var componentTagHelper = tagHelpers.FirstOrDefault(th => th.Kind == TagHelperKind.Component);
+        if (componentTagHelper is null)
+        {
+            snippetText = null;
+            return false;
+        }
+
+        var requiredAttributes = componentTagHelper.EditorRequiredAttributes;
+        if (requiredAttributes.Length == 0)
+        {
+            snippetText = null;
+            return false;
+        }
+
+        // Build snippet with placeholders for each required attribute
+        using var _ = StringBuilderPool.GetPooledObject(out var builder);
+        builder.Append(tagName);
+
+        var tabStopIndex = 1;
+        foreach (var attribute in requiredAttributes)
+        {
+            builder.Append(' ');
+            builder.Append(attribute.Name);
+            builder.Append("=\"$");
+            builder.Append(tabStopIndex);
+            builder.Append('"');
+
+            tabStopIndex++;
+        }
+
+        // Add final tab stop for the element content
+        builder.Append(">$0</");
+        builder.Append(tagName);
+        builder.Append('>');
+
+        snippetText = builder.ToString();
+        return true;
+    }
+
     private enum AttributeContext
     {
         Indexer,

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Resources/SR.resx

@@ -223,4 +223,8 @@
   <data name="ExtractTo_Css_Title" xml:space="preserve">
     <value>Extract to {0}.css</value>
   </data>
+  <data name="ComponentCompletionWithRequiredAttributesLabel" xml:space="preserve">
+    <value>{0} (and req'd attributes...)</value>
+    <comment>The term "req'd" is an abbreviation for "required"</comment>
+  </data>
 </root>