Fixed bun/gorm writer logic for multi files.

pkg/writers/bun/writer.go

@@ -41,12 +41,7 @@ func NewWriter(options *writers.WriterOptions) *Writer {
 // WriteDatabase writes a complete database as Bun models
 func (w *Writer) WriteDatabase(db *models.Database) error {
 	// Check if multi-file mode is enabled
-	multiFile := false
+	multiFile := w.shouldUseMultiFile()
-	if w.options.Metadata != nil {
-		if mf, ok := w.options.Metadata["multi_file"].(bool); ok {
-			multiFile = mf
-		}
-	}
 
 	if multiFile {
 		return w.writeMultiFile(db)
@@ -346,6 +341,41 @@ func (w *Writer) writeOutput(content string) error {
 	return nil
 }
 
+// shouldUseMultiFile determines whether to use multi-file mode based on metadata or output path
+func (w *Writer) shouldUseMultiFile() bool {
+	// Check if multi_file is explicitly set in metadata
+	if w.options.Metadata != nil {
+		if mf, ok := w.options.Metadata["multi_file"].(bool); ok {
+			return mf
+		}
+	}
+
+	// Auto-detect based on output path
+	if w.options.OutputPath == "" {
+		// No output path means stdout (single file)
+		return false
+	}
+
+	// Check if path ends with .go (explicit file)
+	if strings.HasSuffix(w.options.OutputPath, ".go") {
+		return false
+	}
+
+	// Check if path ends with directory separator
+	if strings.HasSuffix(w.options.OutputPath, "/") || strings.HasSuffix(w.options.OutputPath, "\\") {
+		return true
+	}
+
+	// Check if path exists and is a directory
+	info, err := os.Stat(w.options.OutputPath)
+	if err == nil && info.IsDir() {
+		return true
+	}
+
+	// Default to single file for ambiguous cases
+	return false
+}
+
 // createDatabaseRef creates a shallow copy of database without schemas to avoid circular references
 func (w *Writer) createDatabaseRef(db *models.Database) *models.Database {
 	return &models.Database{

pkg/writers/gorm/writer.go

@@ -41,12 +41,7 @@ func NewWriter(options *writers.WriterOptions) *Writer {
 // WriteDatabase writes a complete database as GORM models
 func (w *Writer) WriteDatabase(db *models.Database) error {
 	// Check if multi-file mode is enabled
-	multiFile := false
+	multiFile := w.shouldUseMultiFile()
-	if w.options.Metadata != nil {
-		if mf, ok := w.options.Metadata["multi_file"].(bool); ok {
-			multiFile = mf
-		}
-	}
 
 	if multiFile {
 		return w.writeMultiFile(db)
@@ -340,6 +335,41 @@ func (w *Writer) writeOutput(content string) error {
 	return nil
 }
 
+// shouldUseMultiFile determines whether to use multi-file mode based on metadata or output path
+func (w *Writer) shouldUseMultiFile() bool {
+	// Check if multi_file is explicitly set in metadata
+	if w.options.Metadata != nil {
+		if mf, ok := w.options.Metadata["multi_file"].(bool); ok {
+			return mf
+		}
+	}
+
+	// Auto-detect based on output path
+	if w.options.OutputPath == "" {
+		// No output path means stdout (single file)
+		return false
+	}
+
+	// Check if path ends with .go (explicit file)
+	if strings.HasSuffix(w.options.OutputPath, ".go") {
+		return false
+	}
+
+	// Check if path ends with directory separator
+	if strings.HasSuffix(w.options.OutputPath, "/") || strings.HasSuffix(w.options.OutputPath, "\\") {
+		return true
+	}
+
+	// Check if path exists and is a directory
+	info, err := os.Stat(w.options.OutputPath)
+	if err == nil && info.IsDir() {
+		return true
+	}
+
+	// Default to single file for ambiguous cases
+	return false
+}
+
 // createDatabaseRef creates a shallow copy of database without schemas to avoid circular references
 func (w *Writer) createDatabaseRef(db *models.Database) *models.Database {
 	return &models.Database{