test: more chunked upload tests with different payload types

tests/rest_scripts/command/fileDataSource.go

@@ -0,0 +1,82 @@
+package command
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"os"
+)
+
+type FileDataSource struct {
+	filePath string
+	File     *os.File
+}
+
+func NewFileDataSource(filePath string) *FileDataSource {
+	return &FileDataSource{
+		filePath: filePath,
+		File:     nil,
+	}
+}
+
+func (f *FileDataSource) SourceDataByteSize() (int64, error) {
+	fileInfo, err := os.Stat(f.filePath)
+	if err != nil {
+		return 0, fmt.Errorf("error getting file info: %w", err)
+	}
+	return fileInfo.Size(), nil
+}
+
+func (f *FileDataSource) CalculateSHA256HashString() (string, error) {
+	file, err := os.Open(f.filePath)
+	if err != nil {
+		return "", fmt.Errorf("error opening payload file '%s': %w", f.filePath, err)
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+	if _, err = io.Copy(hasher, file); err != nil {
+		return "", fmt.Errorf("error copying file data of '%s' to hasher: %w", f.filePath, err)
+	}
+
+	hash := hasher.Sum(nil)
+	return hex.EncodeToString(hash), nil
+}
+
+func (f *FileDataSource) Close() error {
+	if f.File != nil {
+		err := f.File.Close()
+		f.File = nil
+		return err
+	}
+	return nil
+}
+
+func (f *FileDataSource) openFile() error {
+	var err error
+	f.File, err = os.OpenFile(f.filePath, os.O_RDONLY, 0600)
+	if err != nil {
+		return fmt.Errorf("error opening file: %w", err)
+	}
+	return nil
+}
+
+func (f *FileDataSource) GetReader() (io.Reader, error) {
+	if f.File == nil {
+		if err := f.openFile(); err != nil {
+			return nil, err
+		}
+	}
+	return f.File, nil
+}
+
+func (f *FileDataSource) GetTeeReader(checksumWriter io.Writer) (io.Reader, error) {
+	if f.File == nil {
+		if err := f.openFile(); err != nil {
+			return nil, err
+		}
+	}
+	r := io.TeeReader(f.File, checksumWriter)
+	return r, nil
+}