whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? serverError(
    1. String message
    )?,
  2. TResult? clientError(
    1. String message
    )?,
})

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>({TResult? Function( String message)?  serverError,TResult? Function( String message)?  clientError,}) {final _that = this;
switch (_that) {
case _ServerError() when serverError != null:
return serverError(_that.message);case _ClientError() when clientError != null:
return clientError(_that.message);case _:
  return null;

}
}