whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? $default(int? id, int? number, String? state, String? title, String? description, String? nodeId, @refParam GithubUserModelRef? creator, int openIssuesCount, int closedIssuesCount, ModelUri? url, ModelUri? htmlUrl, ModelUri? labelsUrl, ModelTimestamp? dueOn, ModelTimestamp? closedAt, ModelTimestamp createdAt, ModelTimestamp updatedAt,)?)

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(
          int? id,
          int? number,
          String? state,
          String? title,
          String? description,
          String? nodeId,
          @refParam GithubUserModelRef? creator,
          int openIssuesCount,
          int closedIssuesCount,
          ModelUri? url,
          ModelUri? htmlUrl,
          ModelUri? labelsUrl,
          ModelTimestamp? dueOn,
          ModelTimestamp? closedAt,
          ModelTimestamp createdAt,
          ModelTimestamp updatedAt)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _GithubMilestoneValue() when $default != null:
      return $default(
          _that.id,
          _that.number,
          _that.state,
          _that.title,
          _that.description,
          _that.nodeId,
          _that.creator,
          _that.openIssuesCount,
          _that.closedIssuesCount,
          _that.url,
          _that.htmlUrl,
          _that.labelsUrl,
          _that.dueOn,
          _that.closedAt,
          _that.createdAt,
          _that.updatedAt);
    case _:
      return null;
  }
}