pkg/analyzer_plugin/lib/src/utilities/library.dart

// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// Returns whether importing the library with URI [library2] into the library
/// with URI [library1] could be a relative import.
///
/// In other words, returns whether each is a 'package:' URI referencing the
/// same package name.
bool canBeRelativeImport(Uri library1, Uri library2) {
  // TODO(srawlins): Replace this with `isSamePackageAs` from
  // 'package:analyzer/src/utilities/extensions/uri.dart', once that is
  // available on pub.
  return library1.isScheme('package') &&
      library2.isScheme('package') &&
      library1.pathSegments.isNotEmpty &&
      library2.pathSegments.isNotEmpty &&
      library1.pathSegments.first == library2.pathSegments.first;
}