fix: remove the generic on _CapsuleManager to allow capsule upcasts (#39

)

Fixes #36

packages/rearch/lib/rearch.dart

@@ -93,15 +93,15 @@ abstract interface class SideEffectApi {
 /// Contains the data of [Capsule]s.
 /// See the documentation for more.
 class CapsuleContainer implements Disposable {
-  final _capsules = <_UntypedCapsule, _UntypedCapsuleManager>{};
+  final _capsules = <_UntypedCapsule, _CapsuleManager>{};
 
   /// Non-null indicates we are currently in a transaction,
   /// with the changed nodes in the set.
   /// When null, we are not in a transaction,
   /// and we can rebuild capsules on the spot normally.
-  Set<_UntypedCapsuleManager>? _managersToRebuildFromTxn;
+  Set<_CapsuleManager>? _managersToRebuildFromTxn;
 
-  void _markNeedsBuild(_UntypedCapsuleManager manager) {
+  void _markNeedsBuild(_CapsuleManager manager) {
     runTransaction(() => _managersToRebuildFromTxn!.add(manager));
   }
 
@@ -126,16 +126,16 @@ class CapsuleContainer implements Disposable {
     }
   }
 
-  _CapsuleManager<T> _managerOf<T>(Capsule<T> capsule) {
+  _CapsuleManager _managerOf(_UntypedCapsule capsule) {
     return _capsules.putIfAbsent(
       capsule,
-      () => _CapsuleManager<T>(this, capsule),
-    ) as _CapsuleManager<T>;
+      () => _CapsuleManager(this, capsule),
+    );
   }
 
   /// Reads the current data of the supplied [Capsule],
   /// initializing it if needed.
-  T read<T>(Capsule<T> capsule) => _managerOf(capsule).data;
+  T read<T>(Capsule<T> capsule) => _managerOf(capsule).data as T;
 
   /// *Temporarily* listens to changes in a given set of [Capsule]s.
   ///

packages/rearch/lib/src/impl.dart

@@ -1,18 +1,17 @@
 part of '../rearch.dart';
 
 typedef _UntypedCapsule = Capsule<Object?>;
-typedef _UntypedCapsuleManager = _CapsuleManager<Object?>;
 
-class _CapsuleManager<T> extends DataflowGraphNode
+class _CapsuleManager extends DataflowGraphNode
     implements SideEffectApi, Disposable {
   _CapsuleManager(this.container, this.capsule) {
     buildSelf();
   }
 
   final CapsuleContainer container;
-  final Capsule<T> capsule;
+  final _UntypedCapsule capsule;
 
-  late T data;
+  late Object? data;
   bool hasBuilt = false;
   bool debugIsBuilding = false;
   final sideEffectData = <Object?>[];
@@ -34,7 +33,7 @@ class _CapsuleManager<T> extends DataflowGraphNode
 
     final otherManager = container._managerOf(otherCapsule);
     addDependency(otherManager);
-    return otherManager.data;
+    return otherManager.data as R;
   }
 
   @override
@@ -94,7 +93,7 @@ class _CapsuleManager<T> extends DataflowGraphNode
 class _CapsuleHandleImpl implements CapsuleHandle {
   _CapsuleHandleImpl(this.manager);
 
-  final _UntypedCapsuleManager manager;
+  final _CapsuleManager manager;
 
   int sideEffectDataIndex = 0;
 

packages/rearch/test/basic_test.dart

@@ -434,4 +434,28 @@ void main() {
     expect(container.read(useInCallbackCapsule), throwsA(anything));
     expect(container.read(useAfterAwaitCapsule), throwsA(anything));
   });
+
+  test('containers store capsules completely untyped (issue #36)', () {
+    // Re-reading the capsule under a different type should not throw.
+    () capsule(CapsuleHandle use) => ();
+    useContainer()
+      // ignore: unnecessary_cast
+      ..read(capsule as Capsule<Object>)
+      ..read(capsule);
+  });
+
+  test('use() in lists works correctly (spun off of issue #36)', () {
+    int intCapsule(CapsuleHandle use) => 0;
+    double doubleCapsule(CapsuleHandle use) => 0;
+    List<num> upcastedListCapsule1(CapsuleHandle use) =>
+        [use(intCapsule), use(doubleCapsule)];
+    List<num> upcastedListCapsule2(CapsuleHandle use) =>
+        [intCapsule, doubleCapsule].map(use.call).toList();
+
+    final container = useContainer();
+    expect(container.read(upcastedListCapsule1), equals([0, 0.0]));
+    expect(container.read(upcastedListCapsule2), equals([0, 0.0]));
+    expect(container.read(intCapsule), equals(0));
+    expect(container.read(doubleCapsule), equals(0.0));
+  });
 }