Fix analyzer RCS1060

ChangeLog.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix enum contained flags check for partial matches in [RCS1258](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1258) ([PR](https://github.com/dotnet/roslynator/pull/1740) by @ovska)
 - Fix analyzer [RCS1146](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1146) ([PR](https://github.com/dotnet/roslynator/pull/1747))
 - Fix analyzer [RCS1194](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1194) ([PR](https://github.com/dotnet/roslynator/pull/1733))
+- Fix analyzer [RCS1060](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1060) to ignore classes marked with `file` modifier ([PR](https://github.com/dotnet/roslynator/pull/1777) by @cbersch)
 - [CLI] Fix `fix` command ignoring `--include` / `--exclude` file filter ([PR](https://github.com/dotnet/roslynator/pull/1758) by @hashiiiii)
 
 ## [4.15.0] - 2025-12-14

src/Analyzers/CSharp/Analysis/DeclareEachTypeInSeparateFileAnalyzer.cs

@@ -60,7 +60,11 @@ void Analyze(SyntaxList<MemberDeclarationSyntax> members)
                 {
                     Analyze(namespaceDeclaration.Members);
                 }
-                else if (SyntaxFacts.IsTypeDeclaration(member.Kind()))
+                else if (SyntaxFacts.IsTypeDeclaration(member.Kind())
+#if ROSLYN_4_4
+                    && !member.Modifiers.Contains(SyntaxKind.FileKeyword)
+#endif
+                    )
                 {
                     if (firstTypeDeclaration is null)
                     {

src/Tests/Analyzers.Tests/RCS1060DeclareEachTypeInSeparateFileTests.cs

@@ -55,6 +55,30 @@ namespace N;
 public class C2
 {
 }
+""");
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.DeclareEachTypeInSeparateFile)]
+    public async Task Test_FirstClassWithFileKeyword_NoDiagnostic()
+    {
+        await VerifyNoDiagnosticAsync("""
+namespace N
+{
+    file class C1;
+    public class C2;
+}
+""");
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.DeclareEachTypeInSeparateFile)]
+    public async Task Test_LastClassWithFileKeyword_NoDiagnostic()
+    {
+        await VerifyNoDiagnosticAsync("""
+namespace N
+{
+    public class C1;
+    file class C2;
+}
 """);
     }
 }