Don't expose AllDelegationTriggerCharacters set

Rather than directly exposing a set, this change adds instance methods to test for valid delegation triggers.

Note this change requires a bit of a test change, but I think it's an improvement since the original test was verifying a Razor scenario that could never happen.

Author: DustinCampbell

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

@@ -32,7 +32,7 @@ internal class CompletionListProvider(
         CancellationToken cancellationToken)
     {
         // First we delegate to get completion items from the individual language server
-        var delegatedCompletionList = CompletionTriggerAndCommitCharacters.IsValidTrigger(_delegatedCompletionListProvider.TriggerCharacters, completionContext)
+        var delegatedCompletionList = _triggerAndCommitCharacters.IsValidDelegationTrigger(completionContext)
             ? await _delegatedCompletionListProvider.GetCompletionListAsync(
                 absoluteIndex,
                 completionContext,

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Completion/Delegation/DelegatedCompletionListProvider.cs

@@ -41,9 +41,6 @@ public DelegatedCompletionListProvider(
         _triggerAndCommitCharacters = completionTriggerAndCommitCharacters;
     }
 
-    // virtual for tests
-    public virtual FrozenSet<string> TriggerCharacters => _triggerAndCommitCharacters.AllDelegationTriggerCharacters;
-
     // virtual for tests
     public virtual async Task<VSInternalCompletionList?> GetCompletionListAsync(
         int absoluteIndex,

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

@@ -28,7 +28,7 @@ internal class CompletionTriggerAndCommitCharacters(LanguageServerFeatureOptions
     public FrozenSet<string> HtmlTriggerCharacters =>
         _languageServerFeatureOptions.UseVsCodeCompletionTriggerCharacters ? s_vsCodeHtmlTriggerCharacters : s_vsHtmlTriggerCharacters;
 
-    public FrozenSet<string> AllDelegationTriggerCharacters => _allDelegationTriggerCharacters
+    private FrozenSet<string> AllDelegationTriggerCharacters => _allDelegationTriggerCharacters
         ??= s_razorDelegationTriggerCharacters.Union(s_csharpTriggerCharacters).Union(HtmlTriggerCharacters).ToFrozenSet();
 
     public string[] AllTriggerCharacters => _allTriggerCharacters ??= [.. s_razorTriggerCharacters.Union(AllDelegationTriggerCharacters)];
@@ -49,12 +49,18 @@ completionContext.TriggerCharacter is null ||
     public bool IsValidCSharpTrigger(CompletionContext completionContext)
         => IsValidTrigger(s_csharpTriggerCharacters, completionContext);
 
+    public bool IsValidDelegationTrigger(CompletionContext completionContext)
+        => IsValidTrigger(AllDelegationTriggerCharacters, completionContext);
+
     public bool IsValidRazorTrigger(CompletionContext completionContext)
         => IsValidTrigger(s_razorTriggerCharacters, completionContext);
 
     public bool IsCSharpTriggerCharacter(string ch)
         => s_csharpTriggerCharacters.Contains(ch);
 
+    public bool IsDelegationTriggerCharacter(string ch)
+        => AllDelegationTriggerCharacters.Contains(ch);
+
     public bool IsRazorTriggerCharacter(string ch)
         => s_razorTriggerCharacters.Contains(ch);
 

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

@@ -4,7 +4,6 @@
 #nullable disable
 
 using System;
-using System.Collections.Frozen;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -22,8 +21,6 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Completion;
 
 public class CompletionListProviderTest : LanguageServerTestBase
 {
-    private const string SharedTriggerCharacter = "@";
-    private const string CompletionList2OnlyTriggerCharacter = "<";
     private readonly VSInternalCompletionList _completionList1;
     private readonly VSInternalCompletionList _completionList2;
     private readonly RazorCompletionListProvider _razorCompletionProvider;
@@ -40,7 +37,7 @@ public CompletionListProviderTest(ITestOutputHelper testOutput)
         _completionList1 = new VSInternalCompletionList() { Items = [] };
         _completionList2 = new VSInternalCompletionList() { Items = [] };
         _razorCompletionProvider = new TestRazorCompletionListProvider(_completionList1, LoggerFactory);
-        _delegatedCompletionProvider = new TestDelegatedCompletionListProvider(_completionList2, new[] { SharedTriggerCharacter, CompletionList2OnlyTriggerCharacter });
+        _delegatedCompletionProvider = new TestDelegatedCompletionListProvider(_completionList2);
         _completionContext = new VSInternalCompletionContext();
         _documentContext = TestDocumentContext.Create("C:/path/to/file.cshtml");
         _clientCapabilities = new VSInternalClientCapabilities();
@@ -69,7 +66,9 @@ public async Task MultipleCompletionLists_DifferentCommitCharacters_OnlyCallsApp
         // Arrange
         var provider = new CompletionListProvider(_razorCompletionProvider, _delegatedCompletionProvider, _triggerAndCommitCharacters);
         _completionContext.TriggerKind = CompletionTriggerKind.TriggerCharacter;
-        _completionContext.TriggerCharacter = CompletionList2OnlyTriggerCharacter;
+
+        // '{' is a commit character for the delegated completion provider but not the Razor completion provider.
+        _completionContext.TriggerCharacter = "{";
 
         // Act
         var completionList = await provider.GetCompletionListAsync(
@@ -83,15 +82,12 @@ private class TestDelegatedCompletionListProvider : DelegatedCompletionListProvi
     {
         private readonly VSInternalCompletionList _completionList;
 
-        public TestDelegatedCompletionListProvider(VSInternalCompletionList completionList, IEnumerable<string> triggerCharacters)
+        public TestDelegatedCompletionListProvider(VSInternalCompletionList completionList)
             : base(null, null, null, null)
         {
             _completionList = completionList;
-            TriggerCharacters = triggerCharacters.ToFrozenSet();
         }
 
-        public override FrozenSet<string> TriggerCharacters { get; }
-
         public override Task<VSInternalCompletionList> GetCompletionListAsync(
             int absoluteIndex,
             VSInternalCompletionContext completionContext,