Add a test, and fix the code that was previously untested :)

Author: davidwengier

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/CodeActions/Razor/ExtractToCssCodeActionProvider.cs

@@ -46,9 +46,10 @@ public Task<ImmutableArray<RazorVSInternalCodeAction>> ProvideAsync(RazorCodeAct
             return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
         }
 
-        if (owner is MarkupTextLiteralSyntax { Parent: MarkupStartTagSyntax })
+        // If we're inside an element, move to the start tag so the following checks work as expected
+        if (owner is MarkupTextLiteralSyntax { Parent: MarkupElementSyntax { StartTag: { } startTag } })
         {
-            owner = owner.Parent;
+            owner = startTag;
         }
 
         // We have to be in a style tag (or inside it, but we'll have moved to the parent if so, above)

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/CodeActions/ExtractToCssTests.cs

@@ -262,6 +262,43 @@ await VerifyCodeActionAsync(
                     """)]);
     }
 
+    [Fact]
+    public async Task ExtractToCss_FromInside()
+    {
+        await VerifyCodeActionAsync(
+            input: """
+                <div></div>
+
+                <style>
+                    body {
+                        back[||]ground-color: red;
+                    }
+                </style>
+
+                @code
+                {
+                    private int x = 1;
+                }
+                """,
+            expected: """
+                <div></div>
+
+
+
+                @code
+                {
+                    private int x = 1;
+                }
+                """,
+            codeActionName: LanguageServerConstants.CodeActions.ExtractToCssAction,
+            additionalExpectedFiles: [
+                (FileUri("File1.razor.css"), $$$"""
+                    body {
+                            background-color: red;
+                        }
+                    """)]);
+    }
+
     [Fact]
     public void GetLastLineNumberAndLength()
     {