resolutionProblems function

List<String> resolutionProblems(String projectPath)

What is wrong with projectPath's .dart_tool/package_config.json, as read from disk — without running pub. Empty means every package the config names is present.

It reports a missing or unreadable config, a package directory that no longer exists (the cache lost it, or a path dependency moved), and a directory that exists without a pubspec.yaml — the one damage dart pub get does not repair.

Implementation

List<String> resolutionProblems(String projectPath) {
  final configFile = File(
    p.join(projectPath, '.dart_tool', 'package_config.json'),
  );
  if (!configFile.existsSync()) {
    return ['no .dart_tool/package_config.json — never resolved here'];
  }
  final Object? decoded;
  try {
    decoded = jsonDecode(configFile.readAsStringSync());
  } on FormatException catch (e) {
    return ['.dart_tool/package_config.json is not valid JSON: ${e.message}'];
  }
  final packages = decoded is Map ? decoded['packages'] : null;
  if (packages is! List) {
    return ['.dart_tool/package_config.json has no "packages" list'];
  }

  final configDir = configFile.parent.uri;
  final problems = <String>[];
  for (final entry in packages) {
    if (entry is! Map) continue;
    final name = entry['name'];
    final rootUri = entry['rootUri'];
    if (name is! String || rootUri is! String) continue;
    // Relative rootUris resolve against the config file's own directory, per
    // the package_config specification; absolute ones are `file:` URIs.
    final root = p.fromUri(configDir.resolve(rootUri));
    if (!Directory(root).existsSync()) {
      problems.add('$name: $root no longer exists');
    } else if (!File(p.join(root, 'pubspec.yaml')).existsSync()) {
      problems.add(
        '$name: $root has no pubspec.yaml — delete that directory, then '
        '`dart pub get` (pub treats its existence as installed)',
      );
    }
  }
  return problems;
}