feat: tested

encfs/file.go

@@ -6,7 +6,6 @@ import (
 	"encoding/binary"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"io"
 	"io/fs"
 	"math"
@@ -114,6 +113,20 @@ func NewEncFile(name string, file *os.File, encFs *EncFs, isCreate bool) (*EncFi
 	}
 	isDir := fileInfo.IsDir()
 	var encFileMeta *EncFileMeta = nil
+
+	fileState, err := os.Stat(name)
+	if err != nil {
+		if os.IsNotExist(err) {
+			isCreate = true
+		} else {
+			return nil, err
+		}
+	} else {
+		if !fileState.IsDir() && fileState.Size() == 0 {
+			isCreate = true
+		}
+	}
+
 	if !isDir {
 		if isCreate {
 			encFileMeta, err = openOrNewEncFileMeta(name)
@@ -193,14 +206,9 @@ func (f *EncFile) Seek(offset int64, whence int) (int64, error) {
 		return 0, checkIsFileErr
 	}
 
-	// I do not understand whence
-	if whence != 0 {
-		return 0, fmt.Errorf("not supported whence: %d", whence)
-	}
-
 	ret, err := f.file.Seek(offset, whence)
 	if err == nil {
-		f.filePos = offset
+		f.filePos = ret
 	}
 	return ret, err
 }