fix: add directory pattern matching to MatchPaths

Add fallback logic to match files within directory patterns
(e.g., "pkg/header/" matches "pkg/header/check.go") to behave
consistently with tryMatchPatten in config.go. Test pattern
without trailing slash now correctly returns false.

Author: jhult

pkg/header/check.go

@@ -162,6 +162,19 @@ func MatchPaths(file string, patterns []string) bool {
 		if err == nil && matched {
 			return true
 		}
+		// Fallback for directory patterns (e.g., "pkg/header/" or "pkg/header")
+		// to behave consistently with tryMatchPatten in config.go.
+		// Ensure that pattern ends with a path separator so it clearly denotes a directory.
+		if strings.HasSuffix(pattern, "/") ||
+			strings.HasSuffix(pattern, string(os.PathSeparator)) {
+			// Treat as directory pattern - match files by prefix
+			// Normalize both paths to use '/' so prefix matching is consistent across platforms.
+			normalizedDir := strings.ReplaceAll(pattern, "\\", "/")
+			normalizedFile := strings.ReplaceAll(file, "\\", "/")
+			if strings.HasPrefix(normalizedFile, normalizedDir) {
+				return true
+			}
+		}
 	}
 	return false
 }

pkg/header/check_test.go

@@ -315,6 +315,12 @@ func TestMatchPaths(t *testing.T) {
 			name:     "Directory pattern with trailing slash",
 			file:     "pkg/header/check.go",
 			patterns: []string{"pkg/header/"},
+			expected: true,
+		},
+		{
+			name:     "Directory pattern without trailing slash",
+			file:     "pkg/header/check.go",
+			patterns: []string{"pkg/header}"},
 			expected: false,
 		},
 		{