You can use the extension
function in the path
package to get the extension from a file path:
import 'package:path/path.dart' as p;
final path="/some/path/to/file/file.dart";
final extension = p.extension(path); // '.dart'
If your file has multiple extensions, like file.dart.js
, you can specify the optional level
parameter:
final extension = p.extension('file.dart.js', 2); // '.dart.js'