pkg/front_end/lib/src/base/library_graph.dart

// Copyright (c) 2018, 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.

import 'package:kernel/kernel.dart'
    show Library, LibraryDependency, LibraryPart;
import 'package:kernel/util/graph.dart' show Graph;

import 'uris.dart' show getPartImportUri;

class LibraryGraph(final Map<Uri, Library> libraries) implements Graph<Uri> {
  @override
  // Coverage-ignore(suite): Not run.
  Iterable<Uri> get vertices => libraries.keys;

  @override
  Iterable<Uri> neighborsOf(Uri vertex) sync* {
    Library? library = libraries[vertex];
    if (library == null) {
      // Coverage-ignore-block(suite): Not run.
      throw "Library not found: $vertex";
    }

    // Imports and exports.
    for (LibraryDependency dependency in library.dependencies) {
      Uri uri1 = dependency.targetLibrary.importUri;
      Uri uri2 = dependency.targetLibrary.fileUri;
      if (libraries.containsKey(uri1)) {
        yield uri1;
      } else {
        if (libraries.containsKey(uri2)) {
          yield uri2;
        }
      }
    }

    // Parts.
    // Normally there won't be libraries for these, but if, for instance,
    // the part didn't exist there will be a synthetic library.
    for (LibraryPart part in library.parts) {
      Uri partImportUri = getPartImportUri(library.importUri, part);
      Uri partFileUri = part.fileUri;
      if (libraries.containsKey(partImportUri)) {
        yield partImportUri;
      } else if (partFileUri != partImportUri &&
          libraries.containsKey(partFileUri)) {
        yield partFileUri;
      }
    }
  }
}