stringArg method
One argument with surrounding string quotes stripped — the common case of a string-literal configuration value.
Implementation
String? stringArg(String label) {
final source = args[label]?.trim();
if (source == null) {
return null;
}
final quoted = (source.startsWith("'") && source.endsWith("'")) ||
(source.startsWith('"') && source.endsWith('"'));
return quoted && source.length >= 2
? source.substring(1, source.length - 1)
: source;
}