Return ImmutableArrays rather than mutable array copies

Rather than returning mutable array copies from AllTriggerCharacters and AllCommitCharacters, return an ImmutableArray and let the call sites make the copies as needed.

Author: DustinCampbell

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

@@ -40,8 +40,8 @@ public void ApplyCapabilities(VSInternalServerCapabilities serverCapabilities, V
         serverCapabilities.CompletionProvider = new CompletionOptions()
         {
             ResolveProvider = true,
-            TriggerCharacters = _triggerAndCommitCharacters.AllTriggerCharacters,
-            AllCommitCharacters = _triggerAndCommitCharacters.AllCommitCharacters
+            TriggerCharacters = [.. _triggerAndCommitCharacters.AllTriggerCharacters],
+            AllCommitCharacters = [.. _triggerAndCommitCharacters.AllCommitCharacters]
         };
     }
 

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

@@ -25,20 +25,16 @@ internal class CompletionTriggerAndCommitCharacters
     private readonly HashSet<char> _delegationTriggerCharacters;
     private readonly HashSet<char> _htmlTriggerCharacters;
     private readonly HashSet<char> _razorTriggerCharacters;
-    private readonly ImmutableArray<string> _allTriggerCharacters;
-    private readonly ImmutableArray<string> _allCommitCharacters;
 
-    // Note: Create a new array each time to avoid modifying the original array.
-    public string[] AllTriggerCharacters => [.. _allTriggerCharacters];
+    public ImmutableArray<string> AllTriggerCharacters { get; }
 
     /// <summary>
     /// This is the intersection of C# and HTML commit characters.
     /// </summary>
     // We need to specify it so that platform can correctly calculate ApplicableToSpan in
     // https://devdiv.visualstudio.com/DevDiv/_git/VSLanguageServerClient?path=/src/product/RemoteLanguage/Impl/Features/Completion/AsyncCompletionSource.cs&version=GBdevelop&line=855&lineEnd=855&lineStartColumn=9&lineEndColumn=49&lineStyle=plain&_a=contents
     // This is needed to fix https://github.com/dotnet/razor/issues/10787 in particular
-    // Note: Create a new array each time to avoid modifying the original array.
-    public string[] AllCommitCharacters => [.. _allCommitCharacters];
+    public ImmutableArray<string> AllCommitCharacters { get; }
 
     public CompletionTriggerAndCommitCharacters(LanguageServerFeatureOptions languageServerFeatureOptions)
     {
@@ -79,8 +75,8 @@ public CompletionTriggerAndCommitCharacters(LanguageServerFeatureOptions languag
         _htmlTriggerCharacters = htmlTriggerCharacters;
         _razorTriggerCharacters = razorTriggerCharacters;
         _delegationTriggerCharacters = delegationTriggerCharacters;
-        _allTriggerCharacters = allTriggerCharacters.SelectAsArray(static c => c.ToString());
-        _allCommitCharacters = commitCharacters.SelectAsArray(static c => c.ToString());
+        AllTriggerCharacters = allTriggerCharacters.SelectAsArray(static c => c.ToString());
+        AllCommitCharacters = commitCharacters.SelectAsArray(static c => c.ToString());
     }
 
     public bool IsValidCSharpTrigger(CompletionContext completionContext)

src/Razor/src/Microsoft.VisualStudio.LanguageServices.Razor/LanguageClient/Cohost/CohostDocumentCompletionEndpoint.cs

@@ -68,8 +68,8 @@ public ImmutableArray<Registration> GetRegistrations(VSInternalClientCapabilitie
                 RegisterOptions = new CompletionRegistrationOptions()
                 {
                     ResolveProvider = false, // TODO - change to true when Resolve is implemented
-                    TriggerCharacters = _triggerAndCommitCharacters.AllTriggerCharacters,
-                    AllCommitCharacters = _triggerAndCommitCharacters.AllCommitCharacters
+                    TriggerCharacters = [.. _triggerAndCommitCharacters.AllTriggerCharacters],
+                    AllCommitCharacters = [.. _triggerAndCommitCharacters.AllCommitCharacters]
                 }
             }];
         }