changelogNotes function

Notes changelogNotes(String markdown, String version, { required String platform, })

The release notes to publish for version on platform.

A version whose own section says nothing about this platform — empty, or entirely [ios] — falls back to the newest earlier version that does. That is not a workaround for a missing entry: a release still has to tell users something, and the most recent thing this platform actually gained is a truer answer than boilerplate. Only when nothing anywhere below qualifies does noUserVisibleChanges go out.

The walk relies on the file being newest-first, which is the convention CHANGELOG.md states and tool/build.sh --release half-enforces by requiring a section for the version being built.

Implementation

Notes changelogNotes(
  String markdown,
  String version, {
  required String platform,
}) {
  final sections = _sections(markdown);
  final start = sections.indexWhere((s) => s.version == version);
  if (start < 0) {
    return const NoSection();
  }
  for (var i = start; i < sections.length; i++) {
    final kept = _forPlatform(sections[i].entries, platform);
    if (kept.isNotEmpty) {
      return NotesText(kept.join('\n'), fromVersion: sections[i].version);
    }
  }
  return const NotesText(noUserVisibleChanges, fromVersion: '');
}