Internal refactoring (#127)

* Implement topological order update algorithm

* Refactoring

* Refactoring

* Track skipping atoms accurately

* Add test cases

* Refactoring

* Support for complex cases of when transitive update is skipped

* Refactoring

* Add more strict testing

* Show all diffs when validation fails

* Fix dev tool cache

* Refactoring

* Update test case to be more strict

* Refactoring

* Add test for topological sort function

* Optimize various use of collection

* Refactor prepareForTransaction

* Minor refactoring

* Minor refactoring

* Refactor watch

* Refactor Transaction

* Minor refactoring

* Minor refactoring

Author: ra1028

Sources/Atoms/AtomRoot.swift

@@ -62,7 +62,7 @@ import SwiftUI
 ///
 public struct AtomRoot<Content: View>: View {
     private var storeHost: StoreHost
-    private var overrides = [OverrideKey: any AtomOverrideProtocol]()
+    private var overrides = [OverrideKey: any OverrideProtocol]()
     private var observers = [Observer]()
     private let content: Content
 
@@ -92,14 +92,14 @@ public struct AtomRoot<Content: View>: View {
     public var body: some View {
         switch storeHost {
         case .tree:
-            TreeHostedStore(
+            TreeManaged(
                 content: content,
                 overrides: overrides,
                 observers: observers
             )
 
         case .unmanaged(let store):
-            UnmanagedStore(
+            Unmanaged(
                 content: content,
                 store: store,
                 overrides: overrides,
@@ -129,7 +129,7 @@ public struct AtomRoot<Content: View>: View {
     ///
     /// - Returns: The self instance.
     public func override<Node: Atom>(_ atom: Node, with value: @escaping (Node) -> Node.Loader.Value) -> Self {
-        mutating(self) { $0.overrides[OverrideKey(atom)] = AtomOverride(isScoped: false, value: value) }
+        mutating(self) { $0.overrides[OverrideKey(atom)] = Override(isScoped: false, value: value) }
     }
 
     /// Overrides the atoms with the given value.
@@ -145,7 +145,7 @@ public struct AtomRoot<Content: View>: View {
     ///
     /// - Returns: The self instance.
     public func override<Node: Atom>(_ atomType: Node.Type, with value: @escaping (Node) -> Node.Loader.Value) -> Self {
-        mutating(self) { $0.overrides[OverrideKey(atomType)] = AtomOverride(isScoped: false, value: value) }
+        mutating(self) { $0.overrides[OverrideKey(atomType)] = Override(isScoped: false, value: value) }
     }
 }
 
@@ -155,15 +155,15 @@ private extension AtomRoot {
         case unmanaged(store: AtomStore)
     }
 
-    struct TreeHostedStore: View {
+    struct TreeManaged: View {
         @MainActor
         final class State: ObservableObject {
             let store = AtomStore()
             let token = ScopeKey.Token()
         }
 
         let content: Content
-        let overrides: [OverrideKey: any AtomOverrideProtocol]
+        let overrides: [OverrideKey: any OverrideProtocol]
         let observers: [Observer]
 
         @StateObject
@@ -185,15 +185,15 @@ private extension AtomRoot {
         }
     }
 
-    struct UnmanagedStore: View {
+    struct Unmanaged: View {
         @MainActor
         final class State: ObservableObject {
             let token = ScopeKey.Token()
         }
 
         let content: Content
         let store: AtomStore
-        let overrides: [OverrideKey: any AtomOverrideProtocol]
+        let overrides: [OverrideKey: any OverrideProtocol]
         let observers: [Observer]
 
         @StateObject

Sources/Atoms/AtomScope.swift

@@ -49,7 +49,7 @@ import SwiftUI
 ///
 public struct AtomScope<Content: View>: View {
     private let inheritance: Inheritance
-    private var overrides: [OverrideKey: any AtomOverrideProtocol]
+    private var overrides: [OverrideKey: any OverrideProtocol]
     private var observers: [Observer]
     private let content: Content
 
@@ -130,7 +130,7 @@ public struct AtomScope<Content: View>: View {
     ///
     /// - Returns: The self instance.
     public func scopedOverride<Node: Atom>(_ atom: Node, with value: @escaping (Node) -> Node.Loader.Value) -> Self {
-        mutating(self) { $0.overrides[OverrideKey(atom)] = AtomOverride(isScoped: true, value: value) }
+        mutating(self) { $0.overrides[OverrideKey(atom)] = Override(isScoped: true, value: value) }
     }
 
     /// Override the atoms used in this scope with the given value.
@@ -148,7 +148,7 @@ public struct AtomScope<Content: View>: View {
     ///
     /// - Returns: The self instance.
     public func scopedOverride<Node: Atom>(_ atomType: Node.Type, with value: @escaping (Node) -> Node.Loader.Value) -> Self {
-        mutating(self) { $0.overrides[OverrideKey(atomType)] = AtomOverride(isScoped: true, value: value) }
+        mutating(self) { $0.overrides[OverrideKey(atomType)] = Override(isScoped: true, value: value) }
     }
 }
 
@@ -166,7 +166,7 @@ private extension AtomScope {
 
         let id: ScopeID
         let content: Content
-        let overrides: [OverrideKey: any AtomOverrideProtocol]
+        let overrides: [OverrideKey: any OverrideProtocol]
         let observers: [Observer]
 
         @StateObject
@@ -190,7 +190,7 @@ private extension AtomScope {
     struct InheritedContext: View {
         let content: Content
         let store: StoreContext
-        let overrides: [OverrideKey: any AtomOverrideProtocol]
+        let overrides: [OverrideKey: any OverrideProtocol]
         let observers: [Observer]
 
         var body: some View {

Sources/Atoms/Context/AtomModifierContext.swift

@@ -1,28 +1,27 @@
 /// A context structure for notifying modifier value updates.
 @MainActor
 public struct AtomModifierContext<Value> {
-    internal let _transaction: Transaction
-    internal let _update: @MainActor (Value) -> Void
+    private let transaction: Transaction
+    private let update: @MainActor (Value) -> Void
 
     internal init(
         transaction: Transaction,
         update: @escaping @MainActor (Value) -> Void
     ) {
-        _transaction = transaction
-        _update = update
+        self.transaction = transaction
+        self.update = update
+    }
+
+    /// A callback to invoke when an atom is released or updated to a new value.
+    public var onTermination: (@MainActor () -> Void)? {
+        get { transaction.onTermination }
+        nonmutating set { transaction.onTermination = newValue }
     }
 
     /// Notifies value updates.
     ///
     /// - Parameter value: An updated value.
     public func update(with value: Value) {
-        _update(value)
-    }
-
-    /// Adds a termination action to be performed when the atom value is updated or released.
-    ///
-    /// - Parameter termination: A termination action.
-    public func addTermination(_ termination: @MainActor @escaping () -> Void) {
-        _transaction.addTermination(termination)
+        update(value)
     }
 }

Sources/Atoms/Context/AtomTestContext.swift

@@ -367,7 +367,7 @@ public struct AtomTestContext: AtomWatchableContext {
     ///   - value: A value to be used instead of the atom's value.
     @inlinable
     public func override<Node: Atom>(_ atom: Node, with value: @escaping (Node) -> Node.Loader.Value) {
-        _state.overrides[OverrideKey(atom)] = AtomOverride(isScoped: false, value: value)
+        _state.overrides[OverrideKey(atom)] = Override(isScoped: false, value: value)
     }
 
     /// Overrides the atom value with the given value.
@@ -382,7 +382,7 @@ public struct AtomTestContext: AtomWatchableContext {
     ///   - value: A value to be used instead of the atom's value.
     @inlinable
     public func override<Node: Atom>(_ atomType: Node.Type, with value: @escaping (Node) -> Node.Loader.Value) {
-        _state.overrides[OverrideKey(atomType)] = AtomOverride(isScoped: false, value: value)
+        _state.overrides[OverrideKey(atomType)] = Override(isScoped: false, value: value)
     }
 }
 
@@ -396,7 +396,7 @@ internal extension AtomTestContext {
         let subscriberState = SubscriberState()
 
         @usableFromInline
-        var overrides = [OverrideKey: any AtomOverrideProtocol]()
+        var overrides = [OverrideKey: any OverrideProtocol]()
 
         @usableFromInline
         var onUpdate: (() -> Void)?

Sources/Atoms/Core/Loader/AsyncSequenceAtomLoader.swift

@@ -30,7 +30,7 @@ public struct AsyncSequenceAtomLoader<Node: AsyncSequenceAtom>: RefreshableAtomL
             }
         }
 
-        context.addTermination(task.cancel)
+        context.onTermination = task.cancel
 
         return .suspending
     }
@@ -61,7 +61,7 @@ public struct AsyncSequenceAtomLoader<Node: AsyncSequenceAtom>: RefreshableAtomL
             return phase
         }
 
-        context.addTermination(task.cancel)
+        context.onTermination = task.cancel
 
         return await withTaskCancellationHandler {
             await task.value

Sources/Atoms/Core/Loader/AtomLoaderContext.swift

@@ -23,26 +23,27 @@ public struct AtomLoaderContext<Value, Coordinator> {
     }
 
     internal var modifierContext: AtomModifierContext<Value> {
-        AtomModifierContext(transaction: transaction) { value in
-            update(with: value)
-        }
+        AtomModifierContext(transaction: transaction, update: update)
     }
 
-    internal func update(with value: Value) {
-        update(value)
+    internal var onTermination: (@MainActor () -> Void)? {
+        get { transaction.onTermination }
+        nonmutating set { transaction.onTermination = newValue }
     }
 
-    internal func addTermination(_ termination: @MainActor @escaping () -> Void) {
-        transaction.addTermination(termination)
+    internal func update(with value: Value) {
+        update(value)
     }
 
     internal func transaction<T>(_ body: @MainActor (AtomTransactionContext<Coordinator>) -> T) -> T {
+        transaction.begin()
         let context = AtomTransactionContext(store: store, transaction: transaction, coordinator: coordinator)
         defer { transaction.commit() }
         return body(context)
     }
 
     internal func transaction<T>(_ body: @MainActor (AtomTransactionContext<Coordinator>) async throws -> T) async rethrows -> T {
+        transaction.begin()
         let context = AtomTransactionContext(store: store, transaction: transaction, coordinator: coordinator)
         defer { transaction.commit() }
         return try await body(context)

Sources/Atoms/Core/Loader/ObservableObjectAtomLoader.swift

@@ -35,7 +35,7 @@ public struct ObservableObjectAtomLoader<Node: ObservableObjectAtom>: AtomLoader
                 }
             }
 
-        context.addTermination(cancellable.cancel)
+        context.onTermination = cancellable.cancel
 
         return value
     }

Sources/Atoms/Core/Loader/PublisherAtomLoader.swift

@@ -25,7 +25,7 @@ public struct PublisherAtomLoader<Node: PublisherAtom>: RefreshableAtomLoader {
             }
         }
 
-        context.addTermination(task.cancel)
+        context.onTermination = task.cancel
 
         return .suspending
     }
@@ -50,7 +50,7 @@ public struct PublisherAtomLoader<Node: PublisherAtom>: RefreshableAtomLoader {
             return phase
         }
 
-        context.addTermination(task.cancel)
+        context.onTermination = task.cancel
 
         return await withTaskCancellationHandler {
             await task.value

Sources/Atoms/Core/Loader/TaskAtomLoader.swift

@@ -28,7 +28,7 @@ public struct TaskAtomLoader<Node: TaskAtom>: AsyncAtomLoader {
 
     /// Manage given overridden value updates and cancellations.
     public func manageOverridden(value: Value, context: Context) -> Value {
-        context.addTermination(value.cancel)
+        context.onTermination = value.cancel
         return value
     }
 
@@ -43,7 +43,7 @@ public struct TaskAtomLoader<Node: TaskAtom>: AsyncAtomLoader {
     /// Refreshes and waits for the passed value to finish outputting values
     /// and returns a final value.
     public func refresh(overridden value: Value, context: Context) async -> Value {
-        context.addTermination(value.cancel)
+        context.onTermination = value.cancel
 
         return await withTaskCancellationHandler {
             _ = await value.result

Sources/Atoms/Core/Loader/ThrowingTaskAtomLoader.swift

@@ -28,7 +28,7 @@ public struct ThrowingTaskAtomLoader<Node: ThrowingTaskAtom>: AsyncAtomLoader {
 
     /// Manage given overridden value updates and cancellations.
     public func manageOverridden(value: Value, context: Context) -> Value {
-        context.addTermination(value.cancel)
+        context.onTermination = value.cancel
         return value
     }
 
@@ -43,7 +43,7 @@ public struct ThrowingTaskAtomLoader<Node: ThrowingTaskAtom>: AsyncAtomLoader {
     /// Refreshes and waits for the passed value to finish outputting values
     /// and returns a final value.
     public func refresh(overridden value: Value, context: Context) async -> Value {
-        context.addTermination(value.cancel)
+        context.onTermination = value.cancel
 
         return await withTaskCancellationHandler {
             _ = await value.result