refactor: code cleanup, stricter config validation (#155)

lib/files.go

@@ -0,0 +1,82 @@
+package lib
+
+import (
+	"context"
+	"mime"
+	"os"
+	"path"
+
+	"golang.org/x/net/webdav"
+)
+
+type Dir struct {
+	webdav.Dir
+	noSniff bool
+}
+
+func (d Dir) Stat(ctx context.Context, name string) (os.FileInfo, error) {
+	// Skip wrapping if NoSniff is off
+	if !d.noSniff {
+		return d.Dir.Stat(ctx, name)
+	}
+
+	info, err := d.Dir.Stat(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	return noSniffFileInfo{info}, nil
+}
+
+func (d Dir) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
+	// Skip wrapping if NoSniff is off
+	if !d.noSniff {
+		return d.Dir.OpenFile(ctx, name, flag, perm)
+	}
+
+	file, err := d.Dir.OpenFile(ctx, name, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+
+	return noSniffFile{File: file}, nil
+}
+
+type noSniffFileInfo struct {
+	os.FileInfo
+}
+
+func (w noSniffFileInfo) ContentType(ctx context.Context) (contentType string, err error) {
+	if mimeType := mime.TypeByExtension(path.Ext(w.FileInfo.Name())); mimeType != "" {
+		// We can figure out the mime from the extension.
+		return mimeType, nil
+	} else {
+		// We can't figure out the mime type without sniffing, call it an octet stream.
+		return "application/octet-stream", nil
+	}
+}
+
+type noSniffFile struct {
+	webdav.File
+}
+
+func (f noSniffFile) Stat() (os.FileInfo, error) {
+	info, err := f.File.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	return noSniffFileInfo{info}, nil
+}
+
+func (f noSniffFile) Readdir(count int) (fis []os.FileInfo, err error) {
+	fis, err = f.File.Readdir(count)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := range fis {
+		fis[i] = noSniffFileInfo{fis[i]}
+	}
+	return fis, nil
+}