feat: Todo 수정 및 삭제를 감지하는 버스 구현

Author: opficdev

Application/DevLogData/Sources/Repository/TodoMutationEventBusImpl.swift

@@ -0,0 +1,37 @@
+//
+//  TodoMutationEventBusImpl.swift
+//  DevLogData
+//
+//  Created by opfic on 6/6/26.
+//
+
+import Foundation
+import DevLogDomain
+
+actor TodoMutationEventBusImpl: TodoMutationEventBus {
+    private var continuations = [UUID: AsyncStream<TodoMutationEvent>.Continuation]()
+
+    func publish(_ event: TodoMutationEvent) async {
+        continuations.values.forEach { $0.yield(event) }
+    }
+
+    func events() -> AsyncStream<TodoMutationEvent> {
+        let id = UUID()
+        let (stream, continuation) = AsyncStream.makeStream(of: TodoMutationEvent.self)
+
+        continuations[id] = continuation
+        continuation.onTermination = { [weak self] _ in
+            Task {
+                await self?.removeContinuation(id: id)
+            }
+        }
+
+        return stream
+    }
+}
+
+private extension TodoMutationEventBusImpl {
+    func removeContinuation(id: UUID) {
+        continuations[id] = nil
+    }
+}

Application/DevLogData/Tests/Repository/TodoMutationEventBusImplTests.swift

@@ -0,0 +1,27 @@
+//
+//  TodoMutationEventBusImplTests.swift
+//  DevLogDataTests
+//
+//  Created by opfic on 6/6/26.
+//
+
+import Testing
+import DevLogDomain
+@testable import DevLogData
+
+struct TodoMutationEventBusImplTests {
+    @Test("TodoMutationEventBus는 발행된 이벤트를 관찰자에게 전달한다")
+    func todoMutationEventBus는_발행된_이벤트를_관찰자에게_전달한다() async {
+        let bus = TodoMutationEventBusImpl()
+        let events = await bus.events()
+        let task = Task {
+            var iterator = events.makeAsyncIterator()
+            return await iterator.next()
+        }
+
+        await bus.publish(.updated("todo-id"))
+
+        let event = await task.value
+        #expect(event == .updated("todo-id"))
+    }
+}

Application/DevLogDomain/Sources/Entity/TodoMutationEvent.swift

@@ -0,0 +1,12 @@
+//
+//  TodoMutationEvent.swift
+//  DevLogDomain
+//
+//  Created by opfic on 6/6/26.
+//
+
+public enum TodoMutationEvent: Equatable, Sendable {
+    case updated(String)
+    case deleted(String)
+    case restored(String)
+}

Application/DevLogDomain/Sources/Protocol/TodoMutationEventBus.swift

@@ -0,0 +1,11 @@
+//
+//  TodoMutationEventBus.swift
+//  DevLogDomain
+//
+//  Created by opfic on 6/6/26.
+//
+
+public protocol TodoMutationEventBus: Sendable {
+    func publish(_ event: TodoMutationEvent) async
+    func events() async -> AsyncStream<TodoMutationEvent>
+}