Function normalizeName

tools/filesystem/file.go:195–236

(fr FileReader, name string)

const randomAlphabet = "abcdefghijklmnopqrstuvwxyz0123456789"

func normalizeName(fr FileReader, name string) string {
	// cut the name even if it is not multibyte safe to avoid operating on too large strings
	// ---
	originalLength := len(name)
	if originalLength > 300 {
		name = name[originalLength-300:]
	}

	// extension
	// ---
	originalExt := extractExtension(name)
	cleanExt := "." + strings.Trim(extInvalidCharsRegex.ReplaceAllString(originalExt, ""), ".")
	if cleanExt == "." {
		// try to detect the extension from the file content
		cleanExt, _ = detectExtension(fr)
	}
	if extLength := len(cleanExt); extLength > 20 {
		// keep only the last 20 characters (it is multibyte safe after the regex replace)
		cleanExt = "." + strings.Trim(cleanExt[extLength-20:], ".")
	}

	// name
	//
	// note: leading dot is trimmed to prevent various subtle issues with files
	// sync programs as they sometimes have special handling for "invisible" files
	// ---
	cleanName := inflector.Snakecase(strings.Trim(strings.TrimSuffix(name, originalExt), "."))
	if length := len(cleanName); length < 3 {
		// the name is too short so we concatenate an additional random part
		cleanName += security.RandomStringWithAlphabet(10, randomAlphabet)
	} else if length > 100 {
		// keep only the first 100 characters (it is multibyte safe after Snakecase)
		cleanName = cleanName[:100]
	}

	return fmt.Sprintf(
		"%s_%s%s",
		cleanName,
		security.RandomStringWithAlphabet(10, randomAlphabet), // ensure that there is always a random part
		cleanExt,
	)
}

// extractExtension extracts the extension (with leading dot) from name.
//