Make the existing test include resolve, and hence fail

Author: davidwengier

src/Razor/test/Microsoft.VisualStudioCode.RazorExtension.Test/Endpoints/Shared/CohostDocumentCompletionEndpointTest.cs

@@ -123,7 +123,16 @@ The end.
                 TriggerCharacter = ".",
                 TriggerKind = CompletionTriggerKind.TriggerCharacter
             },
-            expectedItemLabels: ["DaysInMonth", "IsLeapYear", "Now"]);
+            expectedItemLabels: ["DaysInMonth", "IsLeapYear", "Now"],
+            itemToResolve: "Now",
+            expectedResolvedItemDescription: "DateTime DateTime.Now { get; }",
+            expected: """
+            This is a Razor document.
+            
+            <div>@DateTime.Now</div>
+            
+            The end.
+            """);
     }
 
     [Fact]
@@ -1150,9 +1159,17 @@ private async Task VerifyCompletionResolveAsync(CodeAnalysis.TextDocument docume
             var insertIndex = text.GetRequiredAbsoluteIndex(position);
             changedText = text.WithChanges(new TextChange(new TextSpan(insertIndex, 0), insertText));
         }
+        else if (result.Label is { } label)
+        {
+            // We'll let expected be null here, since its just simple text insertion
+
+            var text = await document.GetTextAsync(DisposalToken).ConfigureAwait(false);
+            var insertIndex = text.GetRequiredAbsoluteIndex(position);
+            changedText = text.WithChanges(new TextChange(new TextSpan(insertIndex, 0), label));
+        }
         else if (expected is not null)
         {
-            Assert.Fail("Expected a TextEdit or Command with TextEdit, but got none. Presumably resolve failed. Result: " + JsonSerializer.SerializeToElement(result).ToString());
+            Assert.Fail("Expected a TextEdit or Command with TextEdit, or InsertText, or Label, but got none. Presumably resolve failed. Result: " + JsonSerializer.SerializeToElement(result).ToString());
         }
 
         if (result.AdditionalTextEdits is not null)