When reporting a bug, please include:

• A little info about your environment
  • npm-package-json-lint version 3.0.0
  • npm version 6.0.0
  • node version 10.0.0
• The output from npm-package-json-lint
  Output error only which in configuration list without rules in extend.
• What you expected to happen
  Respect extends in api
• The steps to reproduce the problem

  new NpmPackageJsonLint().lint(
    packageJsonData, 
    ThisVariableAcceptOnlyArrayOfRulesButShouldAcceptConfigAndRespectExtends
  );

In 2 version all works good and as expected. Thanks!