Fix P0-P3 code review issues for clubs and challenges (FRE-4664)

P0: Fix variable shadowing in ClubService.createClub/updateClub and
    ChallengeService.createChallenge/updateChallenge — renamed local
    'var request' to 'var urlRequest' so JSONEncoder encodes the
    typed parameter, not the URLRequest.

P1: Wire CreateClubSheet and CreateChallengeSheet to parent ViewModel —
    sheets now receive viewModel and call createClub/createChallenge
    before dismissing.

P2: Extract HTTPMethod enum to shared Utils/HTTPMethod.swift (was
    defined in NotificationService). Remove dead 'body' parameter from
    buildRequest in all three services. Add error alert UI to
    ClubsView and ChallengesView.

P3: Replace forced URL unwrap with static let defaultBaseURL in all
    three services. Fix MockChallengeService.updateChallenge to track
    updateCalled instead of always throwing notFound.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

Lendair/Package.swift

@@ -24,6 +24,7 @@ let package = Package(
             sources: [
                 "Models",
                 "Services",
+                "Utils",
                 "ViewModels",
                 "Views"
             ],

Lendair/Services/ChallengeService.swift

@@ -20,8 +20,10 @@ class ChallengeService: ChallengeServiceProtocol {
     private let session: URLSession
     private let authToken: String?
 
+    static let defaultBaseURL: URL = URL(string: "http://localhost:3000")!
+
     init(
-        baseURL: URL = URL(string: "http://localhost:3000")!,
+        baseURL: URL = defaultBaseURL,
         session: URLSession = .shared,
         authToken: String? = nil
     ) {
@@ -62,10 +64,10 @@ class ChallengeService: ChallengeServiceProtocol {
 
     func createChallenge(request: CreateChallengeRequest) async throws -> Challenge {
         let url = baseURL.appendingPathComponent("/api/challenges")
-        var request = try buildRequest(url: url, method: .post)
+        var urlRequest = try buildRequest(url: url, method: .post)
-        request.httpBody = try JSONEncoder().encode(request)
+        urlRequest.httpBody = try JSONEncoder().encode(request)
 
-        let (data, response) = try await session.data(for: request)
+        let (data, response) = try await session.data(for: urlRequest)
         try validateResponse(response)
 
         let decoded = try JSONDecoder().decode(CreateChallengeResponse.self, from: data)
@@ -74,10 +76,10 @@ class ChallengeService: ChallengeServiceProtocol {
 
     func updateChallenge(id: String, request: UpdateChallengeRequest) async throws -> Challenge {
         let url = baseURL.appendingPathComponent("/api/challenges/\(id)")
-        var request = try buildRequest(url: url, method: .patch)
+        var urlRequest = try buildRequest(url: url, method: .patch)
-        request.httpBody = try JSONEncoder().encode(request)
+        urlRequest.httpBody = try JSONEncoder().encode(request)
 
-        let (data, response) = try await session.data(for: request)
+        let (data, response) = try await session.data(for: urlRequest)
         try validateResponse(response)
 
         let decoded = try JSONDecoder().decode(UpdateChallengeResponse.self, from: data)
@@ -124,7 +126,7 @@ class ChallengeService: ChallengeServiceProtocol {
 
     // MARK: - Helpers
 
-    private func buildRequest(url: URL, method: HTTPMethod = .get, body: Data? = nil) throws -> URLRequest {
+    private func buildRequest(url: URL, method: HTTPMethod = .get) throws -> URLRequest {
         var request = URLRequest(url: url)
         request.httpMethod = method.rawValue
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
@@ -133,10 +135,6 @@ class ChallengeService: ChallengeServiceProtocol {
             request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
         }
 
-        if let body = body {
-            request.httpBody = body
-        }
-
         return request
     }
 

Lendair/Services/ClubService.swift

@@ -20,8 +20,10 @@ class ClubService: ClubServiceProtocol {
     private let session: URLSession
     private let authToken: String?
 
+    static let defaultBaseURL: URL = URL(string: "http://localhost:3000")!
+
     init(
-        baseURL: URL = URL(string: "http://localhost:3000")!,
+        baseURL: URL = defaultBaseURL,
         session: URLSession = .shared,
         authToken: String? = nil
     ) {
@@ -63,10 +65,10 @@ class ClubService: ClubServiceProtocol {
 
     func createClub(request: CreateClubRequest) async throws -> Club {
         let url = baseURL.appendingPathComponent("/api/clubs")
-        var request = try buildRequest(url: url, method: .post)
+        var urlRequest = try buildRequest(url: url, method: .post)
-        request.httpBody = try JSONEncoder().encode(request)
+        urlRequest.httpBody = try JSONEncoder().encode(request)
 
-        let (data, response) = try await session.data(for: request)
+        let (data, response) = try await session.data(for: urlRequest)
         try validateResponse(response)
 
         let decoded = try JSONDecoder().decode(CreateClubResponse.self, from: data)
@@ -75,10 +77,10 @@ class ClubService: ClubServiceProtocol {
 
     func updateClub(id: String, request: UpdateClubRequest) async throws -> Club {
         let url = baseURL.appendingPathComponent("/api/clubs/\(id)")
-        var request = try buildRequest(url: url, method: .patch)
+        var urlRequest = try buildRequest(url: url, method: .patch)
-        request.httpBody = try JSONEncoder().encode(request)
+        urlRequest.httpBody = try JSONEncoder().encode(request)
 
-        let (data, response) = try await session.data(for: request)
+        let (data, response) = try await session.data(for: urlRequest)
         try validateResponse(response)
 
         let decoded = try JSONDecoder().decode(UpdateClubResponse.self, from: data)
@@ -120,7 +122,7 @@ class ClubService: ClubServiceProtocol {
 
     // MARK: - Helpers
 
-    private func buildRequest(url: URL, method: HTTPMethod = .get, body: Data? = nil) throws -> URLRequest {
+    private func buildRequest(url: URL, method: HTTPMethod = .get) throws -> URLRequest {
         var request = URLRequest(url: url)
         request.httpMethod = method.rawValue
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
@@ -129,10 +131,6 @@ class ClubService: ClubServiceProtocol {
             request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
         }
 
-        if let body = body {
-            request.httpBody = body
-        }
-
         return request
     }
 

Lendair/Services/NotificationService.swift

@@ -16,8 +16,10 @@ class NotificationsService: NotificationsServiceProtocol {
     private let session: URLSession
     private let authToken: String?
 
+    static let defaultBaseURL: URL = URL(string: "http://localhost:3000")!
+
     init(
-        baseURL: URL = URL(string: "http://localhost:3000")!,
+        baseURL: URL = defaultBaseURL,
         session: URLSession = .shared,
         authToken: String? = nil
     ) {
@@ -76,7 +78,7 @@ class NotificationsService: NotificationsServiceProtocol {
 
     // MARK: - Helpers
 
-    private func buildRequest(url: URL, method: HTTPMethod = .get, body: Data? = nil) throws -> URLRequest {
+    private func buildRequest(url: URL, method: HTTPMethod = .get) throws -> URLRequest {
         var request = URLRequest(url: url)
         request.httpMethod = method.rawValue
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
@@ -85,10 +87,6 @@ class NotificationsService: NotificationsServiceProtocol {
             request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
         }
 
-        if let body = body {
-            request.httpBody = body
-        }
-
         return request
     }
 
@@ -136,11 +134,4 @@ enum NotificationError: LocalizedError {
     }
 }
 
-// MARK: - HTTP Method
+// MARK: - HTTP Method (moved to Utils/HTTPMethod.swift)
-
-enum HTTPMethod: String {
-    case get = "GET"
-    case post = "POST"
-    case patch = "PATCH"
-    case delete = "DELETE"
-}

Lendair/Utils/HTTPMethod.swift

@@ -0,0 +1,8 @@
+import Foundation
+
+enum HTTPMethod: String {
+    case get = "GET"
+    case post = "POST"
+    case patch = "PATCH"
+    case delete = "DELETE"
+}

Lendair/Views/ChallengesView.swift

@@ -4,6 +4,7 @@ struct ChallengesView: View {
     @StateObject private var viewModel = ChallengeViewModel()
     @State private var showingCreateSheet = false
     @State private var selectedTab: ChallengeTab = .active
+    @State private var lastError: ChallengeError?
 
     enum ChallengeTab: String, CaseIterable {
         case active, upcoming, completed
@@ -32,7 +33,12 @@ struct ChallengesView: View {
                 }
             }
             .sheet(isPresented: $showingCreateSheet) {
-                CreateChallengeSheet()
+                CreateChallengeSheet(viewModel: viewModel)
+            }
+            .alert("Error", isPresented: .init(get: { viewModel.error != nil }, set: { if !$0 { lastError = viewModel.error } })) {
+                Button("OK") { lastError = viewModel.error }
+            } message: {
+                Text(viewModel.error?.errorDescription ?? "")
             }
         }
         .onAppear {
@@ -116,6 +122,7 @@ struct ChallengesView: View {
 
 struct CreateChallengeSheet: View {
     @Environment(\.dismiss) var dismiss
+    let viewModel: ChallengeViewModel
     @State private var title = ""
     @State private var description = ""
     @State private var challengeType: ChallengeType = .distance
@@ -177,8 +184,11 @@ struct CreateChallengeSheet: View {
                             rules: rules.isEmpty ? nil : rules,
                             clubId: nil
                         )
+                        Task {
+                            _ = await viewModel.createChallenge(request: request)
                             dismiss()
                         }
+                    }
                     .disabled(title.isEmpty || targetValue.isEmpty)
                 }
             }

Lendair/Views/ClubsView.swift

@@ -4,6 +4,7 @@ struct ClubsView: View {
     @StateObject private var viewModel = ClubViewModel()
     @State private var showingCreateSheet = false
     @State private var selectedTab: ClubTab = .discover
+    @State private var lastError: ClubError?
 
     enum ClubTab: String, CaseIterable {
         case discover, myClubs
@@ -32,7 +33,12 @@ struct ClubsView: View {
                 }
             }
             .sheet(isPresented: $showingCreateSheet) {
-                CreateClubSheet()
+                CreateClubSheet(viewModel: viewModel)
+            }
+            .alert("Error", isPresented: .init(get: { viewModel.error != nil }, set: { if !$0 { lastError = nil } })) {
+                Button("OK") { lastError = viewModel.error }
+            } message: {
+                Text(viewModel.error?.errorDescription ?? "")
             }
         }
         .onAppear {
@@ -112,6 +118,7 @@ struct ClubsView: View {
 
 struct CreateClubSheet: View {
     @Environment(\.dismiss) var dismiss
+    let viewModel: ClubViewModel
     @State private var name = ""
     @State private var description = ""
     @State private var clubType: ClubType = .running
@@ -167,8 +174,11 @@ struct CreateClubSheet: View {
                             maxMembers: Int(maxMembers),
                             rules: rules.isEmpty ? nil : rules
                         )
+                        Task {
+                            _ = await viewModel.createClub(request: request)
                             dismiss()
                         }
+                    }
                     .disabled(name.isEmpty || location.isEmpty)
                 }
             }

LendairTests/ChallengeServiceTests.swift

@@ -10,6 +10,7 @@ final class MockChallengeService: ChallengeServiceProtocol {
     var joinCalledIds: [String] = []
     var leaveCalledIds: [String] = []
     var createCalled = false
+    var updateCalled = false
     var leaderboard: [LeaderboardEntry] = []
     var listCallCount = 0
     var listError: Error?
@@ -51,7 +52,28 @@ final class MockChallengeService: ChallengeServiceProtocol {
     }
 
     func updateChallenge(id: String, request: UpdateChallengeRequest) async throws -> Challenge {
-        throw ChallengeError.notFound
+        updateCalled = true
+        return Challenge(
+            id: id,
+            title: request.title ?? "Updated",
+            description: request.description ?? "",
+            challengeType: request.challengeType ?? .distance,
+            status: .active,
+            startDate: Date(),
+            endDate: Date().addingTimeInterval(30 * 24 * 3600),
+            targetMetric: request.targetMetric ?? .distance,
+            targetValue: request.targetValue ?? 100,
+            targetUnit: (request.targetMetric ?? .distance).unit,
+            participantCount: 0,
+            rules: request.rules,
+            imageUrl: nil,
+            createdBy: "current-user",
+            createdByName: "Current User",
+            clubId: nil,
+            participationStatus: .participating,
+            userProgress: 0,
+            createdAt: Date()
+        )
     }
 
     func joinChallenge(id: String) async throws {