feat(blogo): implementation of default renderer

blogo/defaults.go

@@ -1,6 +1,8 @@
 package blogo
 
 import (
+	"errors"
+	"fmt"
 	"io"
 	"io/fs"
 )
@@ -28,5 +30,46 @@ func (p *defaultRenderer) Name() string {
 }
 
 func (p *defaultRenderer) Render(f fs.File, w io.Writer) error {
+	if d, ok := f.(fs.ReadDirFile); ok {
+		return p.renderDirectory(d, w)
+	}
+
+	buf := make([]byte, 1024)
+	for {
+		n, err := f.Read(buf)
+		if err != nil && err != io.EOF {
+			return err
+		}
+
+		if n == 0 {
+			break
+		}
+
+		_, err = w.Write(buf[:n])
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (p *defaultRenderer) renderDirectory(f fs.ReadDirFile, w io.Writer) error {
+	es, err := f.ReadDir(-1)
+	if err != nil {
+		return err
+	}
+
+	for _, e := range es {
+		s := []byte(fmt.Sprintf("%s", e.Name()))
+		_, err := w.Write(s)
+		if err != nil {
+			return errors.Join(
+				fmt.Errorf("failed to write directory file list, file %s", e.Name()),
+				err,
+			)
+		}
+	}
+
 	return nil
 }