fix(alias): Fix alias not enqueued when one object in collection changes (#60)

Author: pjechris

Sources/CohesionKit/Identity/IdentityStore.swift

@@ -133,7 +133,7 @@ public class IdentityMap {
     /// - Parameter named: the alias to look for
     public func find<T: Identifiable>(named: AliasKey<T>) -> EntityObserver<T?> {
         identityQueue.sync {
-            let node = refAliases[safe: named]
+            let node = refAliases[safe: named, onChange: registry.enqueueChange(for:)]
             return EntityObserver(alias: node, registry: registry)
         }
     }
@@ -142,7 +142,7 @@ public class IdentityMap {
     /// - Returns: an observer returning the alias value. Note that the value will be an Array
     public func find<C: Collection>(named: AliasKey<C>) -> EntityObserver<C?> {
         identityQueue.sync {
-            let node = refAliases[safe: named]
+            let node = refAliases[safe: named, onChange: registry.enqueueChange(for:)]
             return EntityObserver(alias: node, registry: registry)
         }
     }
@@ -195,12 +195,11 @@ public class IdentityMap {
     }
 
     private func storeAlias<T>(content: T, key: AliasKey<T>, modifiedAt: Stamp?) {
-        let aliasNode = refAliases[safe: key]
+        let aliasNode = refAliases[safe: key, onChange: registry.enqueueChange(for:)]
         let aliasContainer = AliasContainer(key: key, content: content)
 
         _ = nodeStore(in: aliasNode, entity: aliasContainer, modifiedAt: modifiedAt)
 
-        registry.enqueueChange(for: aliasNode)
         logger?.didRegisterAlias(key)
     }
 
@@ -274,8 +273,6 @@ extension IdentityMap {
 
             update(&content)
 
-            _ = nodeStore(entity: content, modifiedAt: modifiedAt)
-
             storeAlias(content: content, key: named, modifiedAt: modifiedAt)
 
             return true
@@ -295,8 +292,6 @@ extension IdentityMap {
 
             update(&content)
 
-            _ = nodeStore(entity: content, modifiedAt: modifiedAt)
-
             storeAlias(content: content, key: named, modifiedAt: modifiedAt)
 
             return true
@@ -317,8 +312,6 @@ extension IdentityMap {
 
             update(&content)
 
-            _ = content.map { nodeStore(entity: $0, modifiedAt: modifiedAt) }
-
             storeAlias(content: content, key: named, modifiedAt: modifiedAt)
 
             return true
@@ -339,8 +332,6 @@ extension IdentityMap {
 
             update(&content)
 
-            _ = content.map { nodeStore(entity: $0, modifiedAt: modifiedAt) }
-
             storeAlias(content: content, key: named, modifiedAt: modifiedAt)
 
             return true

Sources/CohesionKit/Observer/ObserverRegistry.swift

@@ -135,4 +135,4 @@ extension ObserverRegistry {
             hasher.combine(ObjectIdentifier(self))
         }
     }
-}
+}

Sources/CohesionKit/Storage/AliasContainer.swift

@@ -10,10 +10,18 @@ struct AliasContainer<T>: Identifiable, Aggregate {
 
 extension AliasContainer {
     var nestedEntitiesKeyPaths: [PartialIdentifiableKeyPath<Self>] {
+        if let self = self as? AggregateKeyPathsEraser {
+            return self.erasedEntitiesKeyPaths as! [PartialIdentifiableKeyPath<Self>]
+        }
+
         if let self = self as? IdentifiableKeyPathsEraser {
             return self.erasedEntitiesKeyPaths as! [PartialIdentifiableKeyPath<Self>]
         }
 
+        if let self = self as? CollectionAggregateKeyPathsEraser {
+            return self.erasedEntitiesKeyPaths as! [PartialIdentifiableKeyPath<Self>]
+        }
+
         if let self = self as? CollectionIdentifiableKeyPathsEraser {
             return self.erasedEntitiesKeyPaths as! [PartialIdentifiableKeyPath<Self>]
         }
@@ -32,6 +40,26 @@ extension AliasContainer: IdentifiableKeyPathsEraser where T: Identifiable {
     }
 }
 
+private protocol AggregateKeyPathsEraser {
+    var erasedEntitiesKeyPaths: [Any] { get }
+}
+
+extension AliasContainer: AggregateKeyPathsEraser where T: Aggregate {
+    var erasedEntitiesKeyPaths: [Any] {
+        [PartialIdentifiableKeyPath<Self>(\.content)]
+    }
+}
+
+private protocol CollectionAggregateKeyPathsEraser {
+    var erasedEntitiesKeyPaths: [Any] { get }
+}
+
+extension AliasContainer: CollectionAggregateKeyPathsEraser where T: MutableCollection, T.Element: Aggregate, T.Index: Hashable {
+    var erasedEntitiesKeyPaths: [Any] {
+        [PartialIdentifiableKeyPath<Self>(\.content)]
+    }
+}
+
 private protocol CollectionIdentifiableKeyPathsEraser {
     var erasedEntitiesKeyPaths: [Any] { get }
 }

Sources/CohesionKit/Storage/AliasStorage.swift

@@ -7,9 +7,9 @@ extension AliasStorage {
         set { self[buildKey(for: T.self, key: aliasKey)] = newValue }
     }
 
-    subscript<T>(safe key: AliasKey<T>) -> EntityNode<AliasContainer<T>> {
+    subscript<T>(safe key: AliasKey<T>, onChange onChange: ((EntityNode<AliasContainer<T>>) -> Void)? = nil) -> EntityNode<AliasContainer<T>> {
         mutating get {
-            self[key: key, default: EntityNode(AliasContainer(key: key), modifiedAt: nil)]
+            self[key: key, default: EntityNode(AliasContainer(key: key), modifiedAt: nil, onChange: onChange)]
         }
     }
 

Tests/CohesionKitTests/IdentityMapTests.swift

@@ -346,7 +346,7 @@ extension IdentityMapTests {
         }
     }
 
-    func test_updateNamed_entityIsCollection_itEnqueuesNestedObjectsInRegistry() {
+    func test_updateNamed_entityIsAggregate_itEnqueuesNestedObjectsInRegistry() {
         let registry = ObserverRegistryStub()
         let identityMap = IdentityMap(registry: registry)
         let initialValue = RootFixture(
@@ -367,6 +367,44 @@ extension IdentityMapTests {
 
         XCTAssertTrue(registry.hasPendingChange(for: singleNodeUpdate))
     }
+
+    func test_updateNamed_aliasIsAggregate_itEnqueuesAliasInRegistry() {
+        let registry = ObserverRegistryStub()
+        let identityMap = IdentityMap(registry: registry)
+        let initialValue = RootFixture(
+            id: 1,
+            primitive: "",
+            singleNode: .init(id: 1),
+            listNodes: []
+        )
+        let singleNodeUpdate = SingleNodeFixture(id: 1, primitive: "update")
+
+        _ = identityMap.store(entity: initialValue, named: .root)
+
+        registry.clearPendingChangesStub()
+
+        identityMap.update(named: .root) {
+            $0.singleNode = singleNodeUpdate
+        }
+
+        XCTAssertTrue(registry.hasPendingChange(for: AliasContainer<RootFixture>.self))
+    }
+
+    func test_update_entityIsIndirectlyUsedByAlias_itEnqueuesAliasInRegistry() {
+        let aggregate = RootFixture(id: 1, primitive: "", singleNode: SingleNodeFixture(id: 1), listNodes: [])
+        let registry = ObserverRegistryStub()
+        let identityMap = IdentityMap(registry: registry)
+
+        _ = identityMap.store(entities: [aggregate], named: .rootList)
+
+        registry.clearPendingChangesStub()
+
+        identityMap.update(SingleNodeFixture.self, id: 1) {
+            $0.primitive = "updated"
+        }
+
+        XCTAssertTrue(registry.hasPendingChange(for: AliasContainer<[RootFixture]>.self))
+    }
 }
 
 private extension AliasKey where T == SingleNodeFixture {
@@ -380,3 +418,7 @@ private extension AliasKey where T == [SingleNodeFixture] {
 private extension AliasKey where T == RootFixture {
     static let root = AliasKey(named: "root")
 }
+
+private extension AliasKey where T == [RootFixture] {
+    static let rootList = AliasKey(named: "root")
+}