runGen function

Future<String> runGen(String projectRoot, { required bool check, required bool shots, })

Writes (or checks) the generated test. Returns a human summary line, or throws StateError in check mode when stale.

Implementation

Future<String> runGen(
  String projectRoot, {
  required bool check,
  required bool shots,
}) async {
  final packageName = packageNameOf(projectRoot);
  if (packageName == null) {
    throw StateError('no pubspec.yaml at $projectRoot');
  }
  final entries = await discoverEntries(projectRoot);
  final raw = generateTestFile(
    packageName: packageName,
    entries: entries,
    shell: hasShellFor(projectRoot),
    shots: shots,
  );
  // Emit format-clean code so consumers' `dart format` checks never fight
  // the generated file.
  final src = DartFormatter(
    languageVersion: DartFormatter.latestLanguageVersion,
  ).format(raw);
  final file = File(p.join(projectRoot, testRelPath));
  final current = file.existsSync() ? file.readAsStringSync() : null;
  if (check) {
    if (current != src) {
      throw StateError(
        '$testRelPath is ${current == null ? 'missing' : 'STALE'} — '
        'run `dart run greenroom` and commit the result.',
      );
    }
  } else if (current != src) {
    file
      ..parent.createSync(recursive: true)
      ..writeAsStringSync(src);
  }
  // The generated file imports flutter_test; without that dev_dependency
  // `flutter test` cannot run it at all. Checked, not assumed.
  final pubspec = File(p.join(projectRoot, 'pubspec.yaml')).readAsStringSync();
  final missingTestDep = !RegExp(
    r'^\s*flutter_test\s*:',
    multiLine: true,
  ).hasMatch(pubspec);

  final mountable = entries.where((e) => e.kind != 'missing').length;
  final missing = entries.length - mountable;
  final notes = entries.where((e) => e.note != null).map((e) => e.note!);
  return [
    if (missingTestDep)
      'WARNING: pubspec.yaml has no flutter_test dependency — '
          '`flutter test` cannot run the generated file. Add:\n'
          '  dev_dependencies:\n    flutter_test:\n      sdk: flutter',
    '$testRelPath: $mountable mount tests'
        '${missing > 0 ? ', $missing missing-entry obligations' : ''}'
        '${shots ? ', screenshots on' : ''}'
        '${check ? ' (check: fresh)' : ''}',
    for (final n in notes) 'note — $n',
  ].join('\n');
}