archive: add "none" compression format (MR 25)

internal/archive/archive.go

@@ -29,6 +29,7 @@ const (
 	FormatGzip CompressFormat = "gzip"
 	FormatLzma CompressFormat = "lzma"
 	FormatZstd CompressFormat = "zstd"
+	FormatNone CompressFormat = "none"
 )
 
 type CompressLevel string
@@ -103,6 +104,7 @@ func ExtractFormatLevel(s string) (format CompressFormat, level CompressLevel) {
 	case FormatLzma:
 		log.Println("Format lzma doesn't support a compression level, using default settings")
 		level = LevelDefault
+	case FormatNone:
 	case FormatZstd:
 	default:
 		log.Print("Unknown or no compression format set, using gzip")
@@ -313,6 +315,8 @@ func (archive *Archive) writeCompressed(path string, mode os.FileMode) (err erro
 		if err != nil {
 			return err
 		}
+	case FormatNone:
+		compressor = fd
 	case FormatZstd:
 		level := zstd.SpeedDefault
 		switch archive.compress_level {

internal/archive/archive_test.go

@@ -238,7 +238,7 @@ func TestExtractFormatLevel(t *testing.T) {
 			expectedLevel:  LevelBest,
 		},
 		{
-			name:           "none, none",
+			name:           "<empty>, <empty>",
 			in:             "",
 			expectedFormat: FormatGzip,
 			expectedLevel:  LevelDefault,
@@ -249,6 +249,12 @@ func TestExtractFormatLevel(t *testing.T) {
 			expectedFormat: FormatLzma,
 			expectedLevel:  LevelDefault,
 		},
+		{
+			name:           "none",
+			in:             "none",
+			expectedFormat: FormatNone,
+			expectedLevel:  LevelDefault,
+		},
 	}
 
 	for _, test := range tests {