Extract Method refactoring misses a required formal parameter

[scheglov]

  void _writeExportRequirements(BundleRequirementsManifest requirements) {
    var exportRequirements = requirements.exportRequirements.sortedBy(
      (requirement) => requirement.exportedUri.toString(),
    );

    sink.writeElements(
      'exportRequirements',
      exportRequirements,
      (requirement) {
        sink.writelnWithIndent(requirement.exportedUri);
        sink.withIndent(() {
          sink.writeElements(
            'combinators',
            requirement.combinators,
            (combinator) {
              switch (combinator) {
                case ExportRequirementHideCombinator():
                  var baseNames = combinator.hiddenBaseNames.sorted();
                  sink.writelnWithIndent('hide ${baseNames.join(', ')}');
                case ExportRequirementShowCombinator():
                  var baseNames = combinator.shownBaseNames.sorted();
                  sink.writelnWithIndent('show ${baseNames.join(', ')}');
              }
            },
          );

          var entries = requirement.exportedIds.sorted;
          for (var entry in entries) {
            _writeNamedId(entry);
          }
        });
      },
    );
  }

Select and try to extract it.

          sink.writeElements(
            'combinators',
            requirement.combinators,
            (combinator) {
              switch (combinator) {
                case ExportRequirementHideCombinator():
                  var baseNames = combinator.hiddenBaseNames.sorted();
                  sink.writelnWithIndent('hide ${baseNames.join(', ')}');
                case ExportRequirementShowCombinator():
                  var baseNames = combinator.shownBaseNames.sorted();
                  sink.writelnWithIndent('show ${baseNames.join(', ')}');
              }
            },
          );

The extracted code uses requirement, but the extracdted method signature does not specify it.

[scheglov]

Oh, I know why.
requirements has type _ExportRequirement, so it cannot be written.

[pq]

In general we don't produce invalid code so just bail out of principle but as per our conversation, there may be some benefit in producing results that are known to be incomplete (but get you at least part of the way), notifying you with, for example, a dialog.

One rub is that while we might be able to do this in IntelliJ, we can't show dialogs in VSCode so it'd be some work to make a uniform experience.

While it's sort of WAI, let's leave this open as food for future thought!