Fix loading of slnf

ChangeLog.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- [CLI] Fix loading of `slnf` files ([PR](https://github.com/dotnet/roslynator/pull/1447))
+
 ## [4.12.1] - 2024-04-15
 
 ### Changed

src/CommandLine/CommandLineHelpers.cs

@@ -20,7 +20,8 @@ public static bool IsGlobPatternForProject(string pattern)
 
     public static bool IsGlobPatternForSolution(string pattern)
     {
-        return pattern.EndsWith(".sln", StringComparison.OrdinalIgnoreCase);
+        return pattern.EndsWith(".sln", StringComparison.OrdinalIgnoreCase)
+            || pattern.EndsWith(".slnf", StringComparison.OrdinalIgnoreCase);
     }
 
     public static void WaitForKeyPress(string message = null)

src/CommandLine/Commands/MSBuildWorkspaceCommand.cs

@@ -72,7 +72,7 @@ public async Task<CommandStatus> ExecuteAsync(IEnumerable<PathInfo> paths, strin
                 {
                     if (path.Origin == PathOrigin.PipedInput)
                     {
-                        Matcher matcher = (string.Equals(Path.GetExtension(path.Path), ".sln", StringComparison.OrdinalIgnoreCase))
+                        Matcher matcher = (IsSolutionFile(path.Path))
                             ? ProjectFilter.SolutionMatcher
                             : ProjectFilter.Matcher;
 
@@ -225,7 +225,7 @@ protected virtual void WorkspaceFailed(object sender, WorkspaceDiagnosticEventAr
         IProgress<ProjectLoadProgress> progress = null,
         CancellationToken cancellationToken = default)
     {
-        bool isSolution = string.Equals(Path.GetExtension(path), ".sln", StringComparison.OrdinalIgnoreCase);
+        bool isSolution = IsSolutionFile(path);
 
         WriteLine($"Loading {((isSolution) ? "solution" : "project")} '{path}'...", Verbosity.Minimal);
 
@@ -405,6 +405,14 @@ private protected bool IsMatch(Project project)
         }
     }
 
+    private static bool IsSolutionFile(string path)
+    {
+        string extension = Path.GetExtension(path);
+
+        return string.Equals(extension, ".sln", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(extension, ".slnf", StringComparison.OrdinalIgnoreCase);
+    }
+
     protected class ConsoleProgressReporter : IProgress<ProjectLoadProgress>
     {
         public static ConsoleProgressReporter Default { get; } = new();