replaceBefore method
Replaces part of string before the first occurrence of given delimiter with the replacement
string.
If the string does not contain the delimiter, returns missingDelimiterValue!
which defaults to the original string.
Implementation
String? replaceBefore(String delimiter, String replacement,
[String? defaultValue]) {
if (this == null) return null;
final index = this!.indexOf(delimiter);
return (index == -1)
? defaultValue!.isNullOrEmpty()
? this
: defaultValue
: this!.replaceRange(0, index, replacement);
}