From 9ea83b343ec122d0bb94798411db46970b91f160 Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Fri, 7 Feb 2025 09:15:02 +1100
Subject: [PATCH] Fix formatting of escaped at signs

---
 ...pFormattingPass.CSharpDocumentGenerator.cs | 11 ++++
 .../DocumentFormattingTest.cs                 | 52 +++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Formatting/Passes/New/CSharpFormattingPass.CSharpDocumentGenerator.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Formatting/Passes/New/CSharpFormattingPass.CSharpDocumentGenerator.cs
index 7458c1158ea..2749cf9efc8 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Formatting/Passes/New/CSharpFormattingPass.CSharpDocumentGenerator.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Formatting/Passes/New/CSharpFormattingPass.CSharpDocumentGenerator.cs
@@ -323,7 +323,18 @@ public override LineInfo VisitRazorMetaCode(RazorMetaCodeSyntax node)
                 return EmitCurrentLineAsCSharp();
             }
 
+            public override LineInfo VisitMarkupEphemeralTextLiteral(MarkupEphemeralTextLiteralSyntax node)
+            {
+                // A MarkupEphemeralTextLiteral is an escaped @ sign, eg in CSS "@@font-face". We just treat it like markup text
+                return VisitMarkupLiteral();
+            }
+
             public override LineInfo VisitMarkupTextLiteral(MarkupTextLiteralSyntax node)
+            {
+                return VisitMarkupLiteral();
+            }
+
+            private LineInfo VisitMarkupLiteral()
             {
                 // For markup text literal, we always want to honour the Html formatter, so we supply the Html indent.
                 // Normally that would only happen if we were inside a markup element
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/DocumentFormattingTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/DocumentFormattingTest.cs
index fac7463775a..e1ce1ec6e9d 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/DocumentFormattingTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/DocumentFormattingTest.cs
@@ -5854,4 +5854,56 @@ void Foo() { }
                 @Foo.ToString(1)
                 """);
     }
+
+    [FormattingTestFact]
+    public async Task EscapedAtSignsInCSS()
+    {
+        await RunFormattingTestAsync(
+            input: """
+                @page "/"
+                @model IndexModel
+
+                <style>
+                    @@media only screen and (max-width: 600px) {
+                        body {
+                            background-color: lightblue;
+                        }
+                    }
+                </style>
+
+                <style>
+                    @@font-face {
+                        src: url();
+                    }
+                </style>
+
+                @if (RendererInfo.IsInteractive)
+                {
+                <button />
+                }
+                """,
+            expected: """
+                @page "/"
+                @model IndexModel
+                
+                <style>
+                    @@media only screen and (max-width: 600px) {
+                        body {
+                            background-color: lightblue;
+                        }
+                    }
+                </style>
+
+                <style>
+                    @@font-face {
+                        src: url();
+                    }
+                </style>
+
+                @if (RendererInfo.IsInteractive)
+                {
+                    <button />
+                }
+                """);
+    }
 }