always_use_package_imports

Use 'package:' imports for files in the 'lib' directory.

The analyzer produces this diagnostic when an import in a library inside the lib directory uses a relative path to import another library inside the lib directory of the same package.

Given that a file named a.dart and the code below are both inside the lib directory of the same package, the following code produces this diagnostic because a relative URI is used to import a.dart:

import 'a.dart';

Use a package import:

import 'package:p/a.dart';