Hacking.

Author: davidmorgan

build/lib/src/internal.dart

@@ -8,6 +8,7 @@ library;
 
 export 'library_cycle_graph/asset_deps.dart';
 export 'library_cycle_graph/asset_deps_loader.dart';
+export 'library_cycle_graph/asset_set.dart';
 export 'library_cycle_graph/library_cycle.dart';
 export 'library_cycle_graph/library_cycle_graph.dart';
 export 'library_cycle_graph/library_cycle_graph_loader.dart';

build/lib/src/library_cycle_graph/asset_set.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2025, 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:built_collection/built_collection.dart';
+import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
+
+import '../asset/id.dart';
+import 'library_cycle_graph.dart';
+
+part 'asset_set.g.dart';
+
+abstract class AssetSet implements Built<AssetSet, AssetSetBuilder> {
+  static Serializer<AssetSet> get serializer => _$assetSetSerializer;
+
+  BuiltSet<AssetId> get assets;
+  BuiltList<LibraryCycleGraph> get graphs;
+
+  factory AssetSet([void Function(AssetSetBuilder) updates]) = _$AssetSet;
+  AssetSet._();
+
+  AssetSet difference(Set<AssetId> other) {
+    throw UnimplementedError();
+  }
+
+  Iterable<AssetId> get iterable sync* {
+    final seenAssets = assets.toSet();
+    yield* assets;
+
+    for (final graph in graphs) {
+      for (final id in graph.transitiveDeps) {
+        if (seenAssets.add(id)) yield id;
+      }
+    }
+  }
+}

build/lib/src/library_cycle_graph/asset_set.g.dart

@@ -4,6 +4,7 @@
 
 import 'package:built_collection/built_collection.dart';
 import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
 
 import '../asset/id.dart';
 
@@ -14,6 +15,8 @@ part 'library_cycle.g.dart';
 /// This means they have to be compiled as a single unit.
 abstract class LibraryCycle
     implements Built<LibraryCycle, LibraryCycleBuilder> {
+  static Serializer<LibraryCycle> get serializer => _$libraryCycleSerializer;
+
   BuiltSet<AssetId> get ids;
 
   factory LibraryCycle([void Function(LibraryCycleBuilder) updates]) =

build/lib/src/library_cycle_graph/library_cycle.dart

@@ -4,6 +4,7 @@
 
 import 'package:built_collection/built_collection.dart';
 import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
 
 import '../asset/id.dart';
 import 'library_cycle.dart';
@@ -13,6 +14,9 @@ part 'library_cycle_graph.g.dart';
 /// A directed acyclic graph of [LibraryCycle]s.
 abstract class LibraryCycleGraph
     implements Built<LibraryCycleGraph, LibraryCycleGraphBuilder> {
+  static Serializer<LibraryCycleGraph> get serializer =>
+      _$libraryCycleGraphSerializer;
+
   LibraryCycle get root;
   BuiltList<LibraryCycleGraph> get children;