[#368] LoadingView 띄우는 형태를 LoadingState()로 관리하여 즉시 뜨는게 아닌 일정 시간 딜레이 후 그 동안에도 비동기 로딩 중이면 뜨도록 개선한다 (#370)

* fix: Task가 취소되지 않았을 경우 로딩을 끝내버릴 수 있는 이슈 해결

* fix: 검색 로딩 상태 반영이 누락되던 문제 수정

* style: SearchViewModel과 동일한 역할 하는 메서드와 이름 일원화

* feat: 검색 액션의 빈 문자열 방어 로직 추가

Author: opficdev

DevLog/Presentation/ViewModel/SearchViewModel.swift

@@ -40,6 +40,8 @@ final class SearchViewModel: Store {
     }
 
     enum SideEffect {
+        case cancelSearch
+        case debounceFetch(String)
         case fetch(String)
     }
 
@@ -103,23 +105,31 @@ final class SearchViewModel: Store {
             state.isLoading = isLoading
         case .setSearching(let isSearching):
             state.isSearching = isSearching
+            if !isSearching {
+                effects = [.cancelSearch]
+            }
         case .setSearchQuery(let query):
             guard state.searchQuery != query else { return [] }
             state.searchQuery = query
             state.showAllTodos = false
             state.showAllWebPages = false
             let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines)
             if trimmed.isEmpty {
-                cancelSearch()
                 state.webPages = []
                 state.todos = []
+                effects = [.cancelSearch]
             } else {
-                cancelSearch()
-                beginLoading(.immediate)
-                scheduleDebouncedFetch(trimmed)
+                effects = [.cancelSearch, .debounceFetch(trimmed)]
             }
         case .applySearchQuery(let query):
-            effects = [.fetch(query)]
+            let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines)
+            if trimmed.isEmpty {
+                state.webPages = []
+                state.todos = []
+                effects = [.cancelSearch]
+            } else {
+                effects = [.fetch(trimmed)]
+            }
         case .setShowAllTodos(let shouldShowAll):
             state.showAllTodos = shouldShowAll
         case .setShowAllWebPages(let shouldShowAll):
@@ -132,6 +142,11 @@ final class SearchViewModel: Store {
 
     func run(_ effect: SideEffect) {
         switch effect {
+        case .cancelSearch:
+            cancelSearch()
+        case .debounceFetch(let query):
+            beginLoading(.immediate)
+            scheduleDebouncedFetch(query)
         case .fetch(let query):
             searchTasks[.request]?.cancel()
             let requestTask = Task { [weak self] in

DevLog/Presentation/ViewModel/TodoListViewModel.swift

@@ -52,7 +52,7 @@ final class TodoListViewModel: Store {
         case upsertTodo(Todo)
 
         // Run
-        case triggerSearch(String)
+        case applySearchQuery(String)
         case fetchSearchResults([TodoListItem])
         case didToggleCompleted(TodoListItem)
         case didTogglePinned(TodoListItem)
@@ -64,6 +64,8 @@ final class TodoListViewModel: Store {
     }
 
     enum SideEffect {
+        case cancelSearch
+        case debounceSearch(String)
         case fetch
         case loadNextPage
         case search(String)
@@ -134,7 +136,7 @@ final class TodoListViewModel: Store {
         case .onAppear, .loadNextPage, .setSearchText, .setToast, .upsertTodo:
             effects = reduceByView(action, state: &state)
 
-        case .triggerSearch, .fetchSearchResults, .didToggleCompleted, .didTogglePinned,
+        case .applySearchQuery, .fetchSearchResults, .didToggleCompleted, .didTogglePinned,
                 .restoreTodo, .setLoading, .appendTodos, .resetPagination, .setHasMore:
             effects = reduceByRun(action, state: &state)
         }
@@ -146,6 +148,11 @@ final class TodoListViewModel: Store {
     // swiftlint:disable function_body_length
     func run(_ effect: SideEffect) {
         switch effect {
+        case .cancelSearch:
+            cancelSearch()
+        case .debounceSearch(let keyword):
+            beginLoading(.immediate)
+            scheduleDebouncedSearch(keyword)
         case .fetch:
             beginLoading(.delayed)
             Task {
@@ -312,10 +319,10 @@ private extension TodoListViewModel {
         case .setIsSearching(let value):
             state.isSearching = value
             if !value {
-                cancelSearch()
                 state.searchText = ""
                 state.searchResults = []
                 state.showAllSearchResults = false
+                return [.cancelSearch]
             }
         case .setShowAllSearchResults(let value):
             state.showAllSearchResults = value
@@ -346,12 +353,10 @@ private extension TodoListViewModel {
             state.showAllSearchResults = false
             let trimmed = text.trimmingCharacters(in: .whitespacesAndNewlines)
             if trimmed.isEmpty {
-                cancelSearch()
                 state.searchResults = []
+                return [.cancelSearch]
             } else {
-                cancelSearch()
-                beginLoading(.immediate)
-                scheduleDebouncedSearch(trimmed)
+                return [.cancelSearch, .debounceSearch(trimmed)]
             }
         case .setToast(let isPresented):
             setToast(&state, isPresented: isPresented)
@@ -366,8 +371,14 @@ private extension TodoListViewModel {
 
     func reduceByRun(_ action: Action, state: inout State) -> [SideEffect] {
         switch action {
-        case .triggerSearch(let query):
-            return [.search(query)]
+        case .applySearchQuery(let query):
+            let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines)
+            if trimmed.isEmpty {
+                state.searchResults = []
+                return [.cancelSearch]
+            } else {
+                return [.search(trimmed)]
+            }
         case .fetchSearchResults(let items):
             state.searchResults = items
         case .didToggleCompleted(let todo):
@@ -435,7 +446,7 @@ private extension TodoListViewModel {
             if Task.isCancelled { return }
             await MainActor.run {
                 self.searchTasks[.debounce] = nil
-                self.send(.triggerSearch(query))
+                self.send(.applySearchQuery(query))
             }
         }
         searchTasks[.debounce] = debounceTask