can you provide a reproduction?

Create a pubspec with no dependencies, then do:

dart pub add path
dart pub add async

You end up with:

dependencies:
  path: ^1.9.1
  async: ^2.13.0

This logic looks wrong to me, it always appends if there is one existing item, rather than assuming it should be alphabetical?

tools/pkgs/yaml_edit/lib/src/utils.dart

Lines 151 to 154 in fe1a6e0

	// We can't deduce ordering if list is empty, so then we just we just append
	if (keys.length <= 1) {
	return map.length;
	}

  // We can't deduce ordering if list is empty, so then we just we just append
  if (keys.length <= 1) {
    return map.length;
  }

Originally posted by @DanTup in #4710