getPackageConfig method

Implementation

Future<File> getPackageConfig() async {
  final dartTool = await getDartTool();

  final packageConfig = dartTool.childFile('package_config.json');

  if (await packageConfig.exists()) {
    return packageConfig;
  }

  final workspaceRef = dartTool.childFile(
    p.join('pub', 'workspace_ref.json'),
  );

  if (!await workspaceRef.exists()) {
    throw Exception('Failed to find package config or workspace_ref');
  }

  final workspaceRefJson =
      jsonDecode(await workspaceRef.readAsString()) as Map;
  final workspaceRoot = switch (workspaceRefJson['workspaceRoot']) {
    final String workspaceRoot => workspaceRoot.replaceAll(
      RegExp(
        '${p.separator}..'
        r'$',
      ),
      '',
    ),
    final other => throw Exception('Invalid workspace root: $other'),
  };

  // clean up path, the workspaceRoot is usually a path relative and is '../../../'

  final workspace = fileSystem.directory(
    p.normalize(p.join(dartTool.path, workspaceRoot)),
  );

  return workspace
      .childDirectory('.dart_tool')
      .childFile('package_config.json');
}