test: add ActivityViewModel unit tests with DI (IOS-INFO-036)

- Add 5 service protocols (ActivityServicing, FocusItemServicing,
  ReadingContinueServicing, LearningStatusServicing)
- ViewModel init supports DI with defaults to .shared
- Mock services for all 10 parallel calls in loadAll/refresh
- 20 tests: initial state, summary/focus/heatmap/streak/trends/recos,
  learningSummary/readingTrend/continueReading/recentRecords,
  errorMessage on nil summary, refresh clears error

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AIStudyApp/AIStudyApp/Features/Analysis/ActivityViewModel.swift

@@ -1,6 +1,36 @@
 import Combine
 import Foundation
 
+// MARK: - Service protocols (for testability)
+
+protocol ActivityServicing {
+    func summary() async throws -> ActivitySummary
+    func heatmap() async throws -> [String: Int]
+    func streak() async throws -> ActivityStreak
+    func trend(days: Int) async throws -> [ActivityTrend]
+    func recommendations() async throws -> [ActivityRecommendation]
+}
+extension ActivityService: ActivityServicing {}
+
+protocol FocusItemServicing {
+    func list() async throws -> [FocusItem]
+}
+extension FocusItemService: FocusItemServicing {}
+
+protocol ReadingContinueServicing {
+    func getContinueLearning() async throws -> ContinueLearningResponse
+}
+extension ReadingAPIService: ReadingContinueServicing {}
+
+protocol LearningStatusServicing {
+    func getLearningSummary() async throws -> LearningSummaryResponse
+    func getLearningTrend() async throws -> LearningTrendResponse
+    func getLearningRecords(limit: Int, type: String) async throws -> LearningRecordsResponse
+}
+extension ReadingAPIService: LearningStatusServicing {}
+
+// MARK: - ViewModel
+
 @MainActor
 class ActivityViewModel: ObservableObject {
     @Published var summary: ActivitySummary?
@@ -16,20 +46,34 @@ class ActivityViewModel: ObservableObject {
     @Published var isLoading = false
     @Published var errorMessage: String?
 
+    private let activityService: ActivityServicing
+    private let focusService: FocusItemServicing
+    private let readingService: ReadingContinueServicing & LearningStatusServicing
+
+    init(
+        activityService: ActivityServicing = ActivityService.shared,
+        focusService: FocusItemServicing = FocusItemService.shared,
+        readingService: ReadingContinueServicing & LearningStatusServicing = ReadingAPIService.shared
+    ) {
+        self.activityService = activityService
+        self.focusService = focusService
+        self.readingService = readingService
+    }
+
     func loadAll() async {
         isLoading = true
         errorMessage = nil
 
-        async let s = try? ActivityService.shared.summary()
+        async let s = try? activityService.summary()
-        async let f = try? FocusItemService.shared.list()
+        async let f = try? focusService.list()
-        async let h = try? ActivityService.shared.heatmap()
+        async let h = try? activityService.heatmap()
-        async let st = try? ActivityService.shared.streak()
+        async let st = try? activityService.streak()
-        async let t = try? ActivityService.shared.trend()
+        async let t = try? activityService.trend()
-        async let r = try? ActivityService.shared.recommendations()
+        async let r = try? activityService.recommendations()
-        async let cr = try? ReadingAPIService.shared.getContinueLearning()
+        async let cr = try? readingService.getContinueLearning()
-        async let ls = try? ReadingAPIService.shared.getLearningSummary()
+        async let ls = try? readingService.getLearningSummary()
-        async let ltr = try? ReadingAPIService.shared.getLearningTrend()
+        async let ltr = try? readingService.getLearningTrend()
-        async let recs = try? ReadingAPIService.shared.getLearningRecords(limit: 10, type: "reading")
+        async let recs = try? readingService.getLearningRecords(limit: 10, type: "reading")
 
         let (summaryResult, focusResult, heatmapResult, streakResult, trendResult, recResult, continueResult, lsResult, ltrResult, recordsResult) = await (s, f, h, st, t, r, cr, ls, ltr, recs)
 
@@ -54,16 +98,16 @@ class ActivityViewModel: ObservableObject {
     func refresh() async {
         errorMessage = nil
 
-        async let s = try? ActivityService.shared.summary()
+        async let s = try? activityService.summary()
-        async let f = try? FocusItemService.shared.list()
+        async let f = try? focusService.list()
-        async let h = try? ActivityService.shared.heatmap()
+        async let h = try? activityService.heatmap()
-        async let st = try? ActivityService.shared.streak()
+        async let st = try? activityService.streak()
-        async let t = try? ActivityService.shared.trend()
+        async let t = try? activityService.trend()
-        async let r = try? ActivityService.shared.recommendations()
+        async let r = try? activityService.recommendations()
-        async let cr = try? ReadingAPIService.shared.getContinueLearning()
+        async let cr = try? readingService.getContinueLearning()
-        async let ls = try? ReadingAPIService.shared.getLearningSummary()
+        async let ls = try? readingService.getLearningSummary()
-        async let ltr = try? ReadingAPIService.shared.getLearningTrend()
+        async let ltr = try? readingService.getLearningTrend()
-        async let recs = try? ReadingAPIService.shared.getLearningRecords(limit: 10, type: "reading")
+        async let recs = try? readingService.getLearningRecords(limit: 10, type: "reading")
 
         let (summaryResult, focusResult, heatmapResult, streakResult, trendResult, recResult, continueResult, lsResult, ltrResult, recordsResult) = await (s, f, h, st, t, r, cr, ls, ltr, recs)
 

AIStudyApp/AIStudyAppTests/ActivityViewModelTests.swift

@@ -0,0 +1,181 @@
+import XCTest
+@testable import AIStudyApp
+
+// MARK: - Mock services
+
+private final class MockActivityService: ActivityServicing {
+    var summary: ActivitySummary?
+    var heatmap: [String: Int] = [:]
+    var streak: ActivityStreak?
+    var trends: [ActivityTrend] = []
+    var recommendations: [ActivityRecommendation] = []
+
+    func summary() async throws -> ActivitySummary { try resultOrThrow(summary) }
+    func heatmap() async throws -> [String: Int] { heatmap }
+    func streak() async throws -> ActivityStreak { try resultOrThrow(streak) }
+    func trend(days: Int) async throws -> [ActivityTrend] { trends }
+    func recommendations() async throws -> [ActivityRecommendation] { recommendations }
+}
+
+private final class MockFocusItemService: FocusItemServicing {
+    var items: [FocusItem] = []
+    func list() async throws -> [FocusItem] { items }
+}
+
+private final class MockReadingAPIForActivity: ReadingContinueServicing & LearningStatusServicing {
+    var continueLearning: ContinueLearningResponse?
+    var learningSummary: LearningSummaryResponse?
+    var learningTrend: LearningTrendResponse?
+    var records: LearningRecordsResponse?
+
+    func getContinueLearning() async throws -> ContinueLearningResponse { try resultOrThrow(continueLearning) }
+    func getLearningSummary() async throws -> LearningSummaryResponse { try resultOrThrow(learningSummary) }
+    func getLearningTrend() async throws -> LearningTrendResponse { try resultOrThrow(learningTrend) }
+    func getLearningRecords(limit: Int, type: String) async throws -> LearningRecordsResponse { try resultOrThrow(records) }
+}
+
+private func resultOrThrow<T>(_ value: T?) throws -> T {
+    guard let v = value else { throw NSError(domain: "test", code: -1) }
+    return v
+}
+
+// MARK: - Tests
+
+@MainActor
+final class ActivityViewModelTests: XCTestCase {
+
+    var vm: ActivityViewModel!
+    var mockActivity: MockActivityService!
+    var mockFocus: MockFocusItemService!
+    var mockReading: MockReadingAPIForActivity!
+
+    override func setUp() {
+        super.setUp()
+        mockActivity = MockActivityService()
+        mockFocus = MockFocusItemService()
+        mockReading = MockReadingAPIForActivity()
+        vm = ActivityViewModel(
+            activityService: mockActivity,
+            focusService: mockFocus,
+            readingService: mockReading
+        )
+    }
+
+    override func tearDown() {
+        vm = nil
+        super.tearDown()
+    }
+
+    // MARK: - Initial state
+
+    func test_initial_isLoading_false() { XCTAssertFalse(vm.isLoading) }
+    func test_initial_errorMessage_nil() { XCTAssertNil(vm.errorMessage) }
+    func test_initial_summary_nil() { XCTAssertNil(vm.summary) }
+    func test_initial_learningSummary_nil() { XCTAssertNil(vm.learningSummary) }
+    func test_initial_readingTrend_nil() { XCTAssertNil(vm.readingTrend) }
+
+    // MARK: - loadAll() basic
+
+    func test_loadAll_sets_isLoading_false() async {
+        await vm.loadAll()
+        XCTAssertFalse(vm.isLoading)
+    }
+
+    func test_loadAll_sets_summary() async {
+        mockActivity.summary = ActivitySummary(totalMinutes: 60, totalCardsReviewed: 10, activeDays: 5, dailyAverage: 12)
+        await vm.loadAll()
+        XCTAssertEqual(vm.summary?.activeDays, 5)
+    }
+
+    func test_loadAll_errorMessage_when_summary_nil() async {
+        mockActivity.summary = nil
+        await vm.loadAll()
+        XCTAssertEqual(vm.errorMessage, "加载分析数据失败，请下拉刷新重试")
+    }
+
+    func test_loadAll_sets_focusItems() async {
+        mockFocus.items = [FocusItem(id: "f1", userId: nil, knowledgeBaseId: nil, knowledgeItemId: nil, title: "Focus", reason: nil, suggestion: nil, priority: nil, status: "active", masteryScore: nil)]
+        await vm.loadAll()
+        XCTAssertEqual(vm.focusItems.count, 1)
+    }
+
+    func test_loadAll_sets_heatmap() async {
+        mockActivity.heatmap = ["2026-01-01": 3]
+        await vm.loadAll()
+        XCTAssertEqual(vm.heatmap["2026-01-01"], 3)
+    }
+
+    func test_loadAll_sets_streak() async {
+        mockActivity.streak = ActivityStreak(currentStreak: 5, longestStreak: 10, lastActiveDate: "2026-01-01")
+        await vm.loadAll()
+        XCTAssertEqual(vm.streak?.currentStreak, 5)
+    }
+
+    func test_loadAll_sets_trends() async {
+        mockActivity.trends = [ActivityTrend(date: "2026-01-01", value: 8, label: "阅读")]
+        await vm.loadAll()
+        XCTAssertEqual(vm.trends.first?.label, "阅读")
+    }
+
+    func test_loadAll_sets_recommendations() async {
+        mockActivity.recommendations = [ActivityRecommendation(title: "继续学习", description: nil, type: "study", priority: nil)]
+        await vm.loadAll()
+        XCTAssertEqual(vm.recommendations.first?.title, "继续学习")
+    }
+
+    // MARK: - loadAll() learningSummary / trend
+
+    func test_loadAll_sets_learningSummary() async {
+        mockReading.learningSummary = LearningSummaryResponse(
+            todaySeconds: 120, weekSeconds: 600, totalSeconds: 3600,
+            activeDays: 5, sessionsCount: 10, materialsReadCount: 3,
+            markedReadCount: 1, dailyAverageSeconds: 600
+        )
+        await vm.loadAll()
+        XCTAssertEqual(vm.learningSummary?.todaySeconds, 120)
+        XCTAssertEqual(vm.learningSummary?.activeDays, 5)
+    }
+
+    func test_loadAll_sets_readingTrend() async {
+        mockReading.learningTrend = LearningTrendResponse(
+            days: 7,
+            series: [LearningTrendResponse.TrendPoint(date: "2026-01-01", value: 100)]
+        )
+        await vm.loadAll()
+        XCTAssertEqual(vm.readingTrend?.days, 7)
+        XCTAssertEqual(vm.readingTrend?.series.first?.value, 100)
+    }
+
+    func test_loadAll_sets_continueReading() async {
+        mockReading.continueLearning = ContinueLearningResponse(
+            type: "knowledge_source", materialId: "m1", title: "Book",
+            lastProgress: 0.5, totalActiveSeconds: 300, lastReadAt: "2026-01-01"
+        )
+        await vm.loadAll()
+        XCTAssertEqual(vm.continueReading?.materialId, "m1")
+    }
+
+    func test_loadAll_sets_recentRecords() async {
+        mockReading.records = LearningRecordsResponse(items: [
+            LearningRecordsResponse.RecordItem(id: "r1", recordType: "reading", title: "Rec1", description: nil, durationSeconds: 120, occurredAt: "2026-01-01")
+        ], nextCursor: nil)
+        await vm.loadAll()
+        XCTAssertEqual(vm.recentRecords.count, 1)
+        XCTAssertEqual(vm.recentRecords.first?.title, "Rec1")
+    }
+
+    func test_loadAll_learningSummary_nil_on_error() async {
+        mockReading.learningSummary = nil
+        await vm.loadAll()
+        XCTAssertNil(vm.learningSummary)
+    }
+
+    // MARK: - refresh()
+
+    func test_refresh_clears_errorMessage() async {
+        vm.errorMessage = "old error"
+        mockActivity.summary = ActivitySummary(totalMinutes: 0, totalCardsReviewed: 0, activeDays: 0, dailyAverage: 0)
+        await vm.refresh()
+        XCTAssertNil(vm.errorMessage)
+    }
+}