[Refactor] LoginViewModel에서 세션/인증 상태 분리 (SessionStore 도입)

Rephoto_iOS/App/ContentView.swift

@@ -6,27 +6,25 @@
 //
 
 import SwiftUI
+import Factory
 
 struct ContentView: View {
-    @State private var loginVM: LoginViewModel
-
-    init(userProvider: UserUseCaseProviderProtocol) {
-        self._loginVM = State(initialValue: LoginViewModel(provider: userProvider))
-    }
+    @Injected(\.sessionStore) private var session
 
     var body: some View {
         Group {
-            if loginVM.isLoggedIn {
+            if session.isLoggedIn {
                 RephotoTabView()
             } else {
-                LoginView(loginVM: loginVM)
+                LoginView(session: session)
             }
         }
+        .task { await session.restore() }
     }
 }
 
 #if DEBUG
 #Preview {
-    ContentView(userProvider: MockUserUseCaseProvider())
+    ContentView()
 }
 #endif

Rephoto_iOS/App/Rephoto_iOSApp.swift

@@ -6,15 +6,12 @@
 //
 
 import SwiftUI
-import Factory
 
 @main
 struct Rephoto_iOSApp: App {
-    @Injected(\.userUseCaseProvider) private var userProvider
-
     var body: some Scene {
         WindowGroup {
-            ContentView(userProvider: userProvider)
+            ContentView()
         }
     }
 }

Rephoto_iOS/Core/DIContainer/AppContainer.swift

@@ -80,6 +80,17 @@ extension Container: @retroactive AutoRegistering {
         }
     }
 
+    // MARK: - Session
+
+    /// 앱 전역 세션. @MainActor 타입이므로 메인 스레드 해석을 전제로 한다 (SwiftUI 뷰 초기화 시점).
+    var sessionStore: Factory<SessionStore> {
+        self {
+            MainActor.assumeIsolated {
+                SessionStore(provider: self.userUseCaseProvider.resolve())
+            }
+        }.singleton
+    }
+
     // MARK: - AutoRegistering
 
     public func autoRegister() {

Rephoto_iOS/Features/RephotoTabView.swift

@@ -10,6 +10,7 @@ import PhotosUI
 import Factory
 
 struct RephotoTabView: View {
+    @Injected(\.sessionStore) private var session
     @Injected(\.homeUseCaseProvider) private var homeProvider
     @Injected(\.searchUseCaseProvider) private var searchProvider
 
@@ -24,6 +25,8 @@ struct RephotoTabView: View {
         }
         .tint(.green)
         .tabBarMinimizeBehavior(.onScrollDown)
+        // 하위 탭(프로필/로그아웃 UI 등)이 @Environment(SessionStore.self)로 세션에 접근
+        .environment(session)
     }
 }
 

Rephoto_iOS/Features/User/Presentation/Session/SessionStore.swift

@@ -0,0 +1,62 @@
+//
+//  SessionStore.swift
+//  Rephoto_iOS
+//
+//  Created by 김도연 on 7/2/26.
+//
+
+import SwiftUI
+
+/// 앱 전역 인증/세션 상태를 소유한다.
+/// 인증 동작(로그인/로그아웃/복원)을 담당하며 실패는 throw로 알린다.
+/// 로딩/에러 같은 화면 표현 상태는 각 화면의 ViewModel이 가진다.
+@Observable
+@MainActor
+final class SessionStore {
+    private let provider: UserUseCaseProviderProtocol
+
+    private(set) var isLoggedIn = false
+    private(set) var userInfo: UserInfo?
+    private(set) var name: String = "리포토"
+
+    init(provider: UserUseCaseProviderProtocol) {
+        self.provider = provider
+
+        provider.setOnRefreshFailed { [weak self] in
+            Task { @MainActor in
+                self?.forceLogout()
+            }
+        }
+    }
+
+    /// 앱 시작 시 저장된 토큰으로 세션 복원 (자동 로그인).
+    func restore() async {
+        guard await provider.hasTokens() else { return }
+        isLoggedIn = true
+        await refreshUser()
+    }
+
+    /// 자격 증명으로 로그인. 실패 시 throw.
+    func login(id: String, password: String) async throws {
+        try await provider.login().execute(loginId: id, password: password)
+        isLoggedIn = true
+        await refreshUser()
+    }
+
+    func logout() async {
+        try? await provider.logout().execute()
+        forceLogout()
+    }
+
+    /// 토큰 리프레시 실패 등으로 인한 강제 로그아웃 (로컬 상태만 정리).
+    func forceLogout() {
+        userInfo = nil
+        isLoggedIn = false
+    }
+
+    private func refreshUser() async {
+        guard let info = try? await provider.fetchUser().execute() else { return }
+        userInfo = info
+        name = info.name
+    }
+}

Rephoto_iOS/Features/User/Presentation/ViewModels/LoginViewModel.swift

@@ -10,8 +10,8 @@ import SwiftUI
 @Observable
 @MainActor
 final class LoginViewModel {
-    let provider: UserUseCaseProviderProtocol
-    
+    private let session: SessionStore
+
     var loginId: String = ""
     var password: String = ""
     private(set) var isLoading = false
@@ -20,25 +20,9 @@ final class LoginViewModel {
         get { errorMessage != nil }
         set { if !newValue { errorMessage = nil } }
     }
-    private(set) var isLoggedIn = false
-    private(set) var userInfo: UserInfo?
-    private(set) var name: String = "리포토"
-
-    init(provider: UserUseCaseProviderProtocol) {
-        self.provider = provider
 
-        provider.setOnRefreshFailed { [weak self] in
-            Task { @MainActor in
-                self?.forceLogout()
-            }
-        }
-    }
-
-    func onAppear() async {
-        if await provider.hasTokens() {
-            isLoggedIn = true
-            await fetchUser()
-        }
+    init(session: SessionStore) {
+        self.session = session
     }
 
     func login() async {
@@ -51,47 +35,11 @@ final class LoginViewModel {
         errorMessage = nil
 
         do {
-            try await provider.login().execute(loginId: loginId, password: password)
-            isLoggedIn = true
-            await fetchUser()
+            try await session.login(id: loginId, password: password)
         } catch {
             errorMessage = "로그인 실패: \(error.localizedDescription)"
         }
 
         isLoading = false
     }
-
-    func fetchUser() async {
-        isLoading = true
-        errorMessage = nil
-
-        do {
-            let info = try await provider.fetchUser().execute()
-            userInfo = info
-            name = info.name
-        } catch {
-            errorMessage = "내 정보 조회 실패: \(error.localizedDescription)"
-        }
-
-        isLoading = false
-    }
-
-    func logout() async {
-        isLoading = true
-        errorMessage = nil
-
-        do {
-            try await provider.logout().execute()
-        } catch {
-            errorMessage = "로그아웃 실패: \(error.localizedDescription)"
-        }
-
-        forceLogout()
-        isLoading = false
-    }
-
-    func forceLogout() {
-        userInfo = nil
-        isLoggedIn = false
-    }
 }

Rephoto_iOS/Features/User/Presentation/Views/LoginView.swift

@@ -8,7 +8,11 @@
 import SwiftUI
 
 struct LoginView: View {
-    @Bindable var loginVM: LoginViewModel
+    @State private var loginVM: LoginViewModel
+
+    init(session: SessionStore) {
+        self._loginVM = State(initialValue: LoginViewModel(session: session))
+    }
 
     var body: some View {
         ZStack {
@@ -26,7 +30,6 @@ struct LoginView: View {
                 Text(message)
             }
         }
-        .task { await loginVM.onAppear() }
     }
 
     // MARK: - Title
@@ -91,6 +94,6 @@ struct LoginView: View {
 
 #if DEBUG
 #Preview("Login") {
-    LoginView(loginVM: LoginViewModel(provider: MockUserUseCaseProvider()))
+    LoginView(session: SessionStore(provider: MockUserUseCaseProvider()))
 }
 #endif

Rephoto_iOSTests/LoginViewModelTests.swift

@@ -0,0 +1,77 @@
+//
+//  LoginViewModelTests.swift
+//  Rephoto_iOSTests
+//
+//  로그인 화면 ViewModel의 표현 상태 검증.
+//  - 입력 검증(빈 필드) 시 에러 메시지, 세션 호출 없음
+//  - 로그인 성공/실패 시 isLoading/errorMessage 상태 전이
+//
+
+import XCTest
+@testable import Rephoto_iOS
+
+@MainActor
+final class LoginViewModelTests: XCTestCase {
+
+    private var provider: MockUserUseCaseProvider!
+    private var session: SessionStore!
+    private var sut: LoginViewModel!
+
+    override func setUp() async throws {
+        try await super.setUp()
+        provider = MockUserUseCaseProvider()
+        session = SessionStore(provider: provider)
+        sut = LoginViewModel(session: session)
+    }
+
+    override func tearDown() async throws {
+        sut = nil
+        session = nil
+        provider = nil
+        try await super.tearDown()
+    }
+
+    func test_login_emptyFields_setsValidationError_withoutCallingSession() async {
+        sut.loginId = ""
+        sut.password = "pw"
+
+        await sut.login()
+
+        XCTAssertEqual(sut.errorMessage, "아이디와 비밀번호를 입력해주세요.")
+        XCTAssertEqual(provider.loginCallCount, 0)
+        XCTAssertFalse(session.isLoggedIn)
+    }
+
+    func test_login_success_logsInWithoutError() async {
+        provider.fetchUserResult = .success(UserInfo(userId: 1, loginId: 100, name: "도연"))
+        sut.loginId = "dodle"
+        sut.password = "pw"
+
+        await sut.login()
+
+        XCTAssertNil(sut.errorMessage)
+        XCTAssertFalse(sut.isLoading)
+        XCTAssertTrue(session.isLoggedIn)
+    }
+
+    func test_login_failure_setsErrorMessage_andEndsLoading() async {
+        provider.loginResult = .failure(MockUserError.loginFailed)
+        sut.loginId = "dodle"
+        sut.password = "pw"
+
+        await sut.login()
+
+        XCTAssertNotNil(sut.errorMessage)
+        XCTAssertTrue(sut.isShowingError)
+        XCTAssertFalse(sut.isLoading)
+        XCTAssertFalse(session.isLoggedIn)
+    }
+
+    func test_isShowingError_setFalse_clearsErrorMessage() {
+        sut.errorMessage = "에러"
+
+        sut.isShowingError = false
+
+        XCTAssertNil(sut.errorMessage)
+    }
+}