fix: Display error state when trip doesn't exist

iosApp/iosApp/Pages/TripDetails/TripDetailsPage.swift

@@ -11,7 +11,7 @@
 import SwiftPhoenixClient
 import SwiftUI
 
 struct TripDetailsPage: View {
     let tripId: String
     let vehicleId: String
     let routeId: String
@@ -24,6 +24,7 @@
     @State var globalResponse: GlobalResponse?
     @State var tripPredictionsRepository: ITripPredictionsRepository
     @State var tripPredictions: PredictionsStreamDataResponse?
+    @State var tripPredictionsLoaded: Bool = false
     @State var tripRepository: ITripRepository
     @State var trip: Trip?
     @State var tripSchedulesResponse: TripSchedulesResponse?
@@ -71,9 +72,10 @@
     var body: some View {
         VStack(spacing: 16) {
             header
-            if let trip, let globalResponse, let vehicle = vehicleResponse?.vehicle,
+            if tripPredictionsLoaded, let globalResponse, let vehicle = vehicleResponse?.vehicle,
                let stops = TripDetailsStopList.companion.fromPieces(
-                   trip: trip,
+                   tripId: tripId,
+                   directionId: trip?.directionId ?? vehicle.directionId,
                    tripSchedules: tripSchedulesResponse,
                    tripPredictions: tripPredictions,
                    vehicle: vehicle,
@@ -120,6 +122,10 @@
         .onAppear { joinRealtime() }
         .onDisappear { leaveRealtime() }
         .onChange(of: tripId) {
+            errorBannerVM.errorRepository.clearDataError(key: "TripDetailsPage.loadTripSchedules")
+            errorBannerVM.errorRepository.clearDataError(key: "TripDetailsPage.loadTrip")
+            loadTripSchedules()
+            loadTrip()
             leavePredictions()
             joinPredictions(tripId: $0)
         }
@@ -221,12 +227,14 @@
                 case let .ok(result): tripPredictions = result.data
                 case .error: break
                 }
+                tripPredictionsLoaded = true
                 checkPredictionsStale()
             }
         }
     }
 
     private func leavePredictions() {
+        tripPredictionsLoaded = false
         tripPredictionsRepository.disconnect()
     }
 
@@ -276,7 +284,7 @@
         } else {
             nil
         }
-        let route: Route? = if let routeId = trip?.routeId {
+        let route: Route? = if let routeId = trip?.routeId ?? vehicle?.routeId {
             globalResponse?.routes[routeId]
         } else {
             nil
@@ -285,14 +293,15 @@
             vehicle: vehicle,
             route: route,
             stop: vehicleStop,
-            trip: trip
+            tripId: tripId
         )
     }
 
     @ViewBuilder
     var header: some View {
         let trip: Trip? = tripPredictions?.trips[tripId]
-        let route: Route? = if let routeId = trip?.routeId {
+        let vehicle: Vehicle? = vehicleResponse?.vehicle
+        let route: Route? = if let routeId = trip?.routeId ?? vehicle?.routeId {
             globalResponse?.routes[routeId]
         } else {
             nil

iosApp/iosApp/Pages/TripDetails/VehicleCardView.swift

@@ -14,18 +14,18 @@ struct VehicleCardView: View {
     let vehicle: Vehicle?
     let route: Route?
     let stop: Stop?
-    let trip: Trip?
+    let tripId: String
 
     var body: some View {
-        if let vehicle, let route, let stop, let trip {
+        if let vehicle, let route, let stop {
             VehicleOnTripView(
                 vehicle: vehicle,
                 route: route,
                 stop: stop,
-                trip: trip
+                tripId: tripId
             )
         } else {
-            Text("Loading...")
+            EmptyView()
         }
     }
 }
@@ -34,7 +34,7 @@ struct VehicleOnTripView: View {
     let vehicle: Vehicle
     let route: Route
     let stop: Stop
-    let trip: Trip
+    let tripId: String
 
     var backgroundColor: Color {
         Color(hex: route.color)
@@ -58,7 +58,7 @@ struct VehicleOnTripView: View {
 
     @ViewBuilder
     private var description: some View {
-        if vehicle.tripId == trip.id {
+        if vehicle.tripId == tripId {
             VStack(alignment: .leading, spacing: 2) {
                 vehicleStatusDescription(vehicle.currentStatus)
                     .font(Typography.caption)
@@ -162,7 +162,7 @@ struct VehicleCardView_Previews: PreviewProvider {
         }
 
         List {
-            VehicleCardView(vehicle: vehicle, route: red, stop: stop, trip: trip)
+            VehicleCardView(vehicle: vehicle, route: red, stop: stop, tripId: trip.id)
         }
         .previewDisplayName("VehicleCard")
     }

iosApp/iosAppTests/Pages/TripDetails/TripDetailsPageTests.swift

@@ -172,21 +172,21 @@ final class TripDetailsPageTests: XCTestCase {
         let vehicleId = "999"
         let nearbyVM = NearbyViewModel()
         nearbyVM.alerts = .init(alerts: [:])
-        var sut = TripDetailsPage(
+        let sut = TripDetailsPage(
             tripId: tripId,
             vehicleId: vehicleId,
             routeId: trip.routeId,
             target: .init(stopId: stop1.id, stopSequence: 998),
             errorBannerVM: .init(),
             nearbyVM: nearbyVM,
             mapVM: .init(),
-            globalRepository: MockGlobalRepository(response: .init(objects: objects, patternIdsByStop: [:])),
+            globalRepository: MockGlobalRepository(response: .init(objects: objects)),
             tripPredictionsRepository: FakeTripPredictionsRepository(response: .init(objects: objects)),
             tripRepository: tripRepository,
             vehicleRepository: FakeVehicleRepository(response: .init(vehicle: vehicle))
         )
 
-        let splitViewExp = sut.on(\.didLoadData) { view in
+        let splitViewExp = sut.inspection.inspect(onReceive: tripSchedulesLoaded, after: 0.5) { view in
             XCTAssertNotNil(try view.find(TripDetailsStopListSplitView.self))
         }
 
@@ -307,15 +307,13 @@ final class TripDetailsPageTests: XCTestCase {
         wait(for: [routeExp], timeout: 5)
     }
 
-    @MainActor func testTripRequestError() throws {
+    @MainActor func testMissingTrip() throws {
         let objects = ObjectCollectionBuilder()
 
-        let trip = objects.trip { trip in
-            trip.routeId = "Red"
-        }
+        let tripId = "ADDED-trip"
 
         let vehicle = objects.vehicle { vehicle in
-            vehicle.tripId = trip.id
+            vehicle.tripId = tripId
             vehicle.currentStatus = .inTransitTo
         }
 
@@ -336,15 +334,16 @@ final class TripDetailsPageTests: XCTestCase {
             onConnect: { _ in tripPredictionsLoaded.send() }
         )
 
-        let tripId = trip.id
         let vehicleId = vehicle.id
+        let nearbyVM = NearbyViewModel(alertsRepository: MockAlertsRepository())
+        nearbyVM.alerts = .init(alerts: [:])
         let sut = TripDetailsPage(
             tripId: tripId,
             vehicleId: vehicleId,
-            routeId: trip.routeId,
+            routeId: "Red",
             target: nil,
             errorBannerVM: .init(),
-            nearbyVM: .init(),
+            nearbyVM: nearbyVM,
             mapVM: .init(),
             globalRepository: MockGlobalRepository(response: globalData),
             tripPredictionsRepository: tripPredictionsRepository,
@@ -355,9 +354,8 @@ final class TripDetailsPageTests: XCTestCase {
         let everythingLoaded = tripSchedulesLoaded.zip(tripPredictionsLoaded)
 
         let routeExp = sut.inspection.inspect(onReceive: everythingLoaded, after: 0.1) { view in
-            XCTAssertNotNil(try view.find(where: { view in
-                (try? view.modifier(LoadingPlaceholderModifier.self)) != nil
-            }))
+            XCTAssertNotNil(try view.find(VehicleCardView.self))
+            XCTAssertThrowsError(try view.find(TripDetailsStopView.self))
         }
 
         ViewHosting.host(view: sut)
@@ -647,11 +645,11 @@ final class TripDetailsPageTests: XCTestCase {
     }
 
     class FakeTripPredictionsRepository: ITripPredictionsRepository {
-        let response: PredictionsStreamDataResponse
+        let response: PredictionsStreamDataResponse?
         let onConnect: ((_ tripId: String) -> Void)?
         let onDisconnect: (() -> Void)?
 
-        init(response: PredictionsStreamDataResponse,
+        init(response: PredictionsStreamDataResponse?,
              onConnect: ((_ tripId: String) -> Void)? = nil,
              onDisconnect: (() -> Void)? = nil) {
             self.response = response
@@ -664,7 +662,12 @@ final class TripDetailsPageTests: XCTestCase {
             onReceive: @escaping (ApiResult<PredictionsStreamDataResponse>) -> Void
         ) {
             onConnect?(tripId)
-            onReceive(ApiResultOk(data: response))
+            let result = if let response {
+                ApiResultOk(data: response)
+            } else {
+                ApiResultError<PredictionsStreamDataResponse>(code: 404, message: "Failed to load predictions")
+            }
+            onReceive(result)
         }
 
         var lastUpdated: Instant?

iosApp/iosAppTests/Pages/TripDetails/VehicleCardViewTests.swift

@@ -30,7 +30,7 @@ final class VehicleCardViewTests: XCTestCase {
         }
         let stop = objects.stop { _ in }
 
-        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, trip: trip)
+        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, tripId: trip.id)
         XCTAssertNotNil(try sut.inspect().find(text: "This vehicle is completing another trip"))
     }
 
@@ -49,7 +49,7 @@ final class VehicleCardViewTests: XCTestCase {
             stop.name = "Davis"
         }
 
-        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, trip: trip)
+        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, tripId: trip.id)
         XCTAssertNotNil(try sut.inspect().find(text: "Approaching"))
         XCTAssertNotNil(try sut.inspect().find(text: "Davis"))
     }
@@ -67,7 +67,7 @@ final class VehicleCardViewTests: XCTestCase {
         let route = objects.route { _ in }
         let stop = objects.stop { _ in }
 
-        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, trip: trip)
+        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, tripId: trip.id)
         XCTAssertNotNil(try sut.inspect().find(text: "Next stop"))
     }
 
@@ -84,7 +84,7 @@ final class VehicleCardViewTests: XCTestCase {
         let route = objects.route { _ in }
         let stop = objects.stop { _ in }
 
-        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, trip: trip)
+        let sut = VehicleCardView(vehicle: vehicle, route: route, stop: stop, tripId: trip.id)
         XCTAssertNotNil(try sut.inspect().find(text: "Now at"))
     }
 
@@ -95,7 +95,7 @@ final class VehicleCardViewTests: XCTestCase {
             trip.headsign = "Alewife"
         }
 
-        let sut = VehicleCardView(vehicle: nil, route: nil, stop: nil, trip: trip)
-        XCTAssertNotNil(try sut.inspect().find(text: "Loading..."))
+        let sut = VehicleCardView(vehicle: nil, route: nil, stop: nil, tripId: trip.id)
+        XCTAssertThrowsError(try sut.inspect().find(VehicleOnTripView.self))
     }
 }

shared/src/commonMain/kotlin/com/mbta/tid/mbta_app/model/TripDetailsStopList.kt

@@ -126,24 +126,28 @@ data class TripDetailsStopList(val stops: List<Entry>) {
         }
 
         fun fromPieces(
-            trip: Trip,
+            tripId: String,
+            directionId: Int,
             tripSchedules: TripSchedulesResponse?,
             tripPredictions: PredictionsStreamDataResponse?,
             vehicle: Vehicle?,
             alertsData: AlertsStreamDataResponse?,
             globalData: GlobalResponse,
         ): TripDetailsStopList? {
-            if (tripPredictions == null || alertsData == null) return null
+            if (alertsData == null) return null
             val entries = mutableMapOf<Int, WorkingEntry>()
 
-            val predictions =
-                deduplicatePredictionsByStopSequence(
-                    tripPredictions.predictions.values,
-                    tripSchedules,
-                    globalData
-                )
+            var predictions = emptyList<Prediction>()
+            if (tripPredictions != null) {
+                predictions =
+                    deduplicatePredictionsByStopSequence(
+                        tripPredictions.predictions.values,
+                        tripSchedules,
+                        globalData
+                    )
 
-            predictions.forEach { prediction -> entries.putPrediction(prediction, vehicle) }
+                predictions.forEach { prediction -> entries.putPrediction(prediction, vehicle) }
+            }
 
             if (tripSchedules is TripSchedulesResponse.Schedules) {
                 tripSchedules.schedules.forEach { entries.putSchedule(it) }
@@ -159,15 +163,15 @@ data class TripDetailsStopList(val stops: List<Entry>) {
             }
 
             if (entries.isEmpty()) {
-                return null
+                return TripDetailsStopList(emptyList())
             }
             return TripDetailsStopList(
                 entries.entries
                     .sortedBy { it.key }
                     .dropWhile {
                         if (
                             vehicle == null ||
-                                vehicle.tripId != trip.id ||
+                                vehicle.tripId != tripId ||
                                 vehicle.currentStopSequence == null
                         ) {
                             false
@@ -179,7 +183,7 @@ data class TripDetailsStopList(val stops: List<Entry>) {
                         Entry(
                             globalData.stops.getValue(it.value.stopId),
                             it.value.stopSequence,
-                            getAlert(it.value, alertsData, globalData, trip),
+                            getAlert(it.value, alertsData, globalData, tripId, directionId),
                             it.value.schedule,
                             it.value.prediction,
                             it.value.vehicle,
@@ -316,8 +320,9 @@ data class TripDetailsStopList(val stops: List<Entry>) {
                 while (scheduleIndex in stopIds.indices && predictionIndex in predictions.indices) {
                     val stopId = stopIds[scheduleIndex]
                     val prediction = predictions[predictionIndex]
-                    check(Stop.equalOrFamily(stopId, prediction.stopId, globalData.stops)) {
-                        "predictions=$predictions stopIds=$stopIds predictionIndex=$predictionIndex scheduleIndex=$scheduleIndex"
+                    if (!Stop.equalOrFamily(stopId, prediction.stopId, globalData.stops)) {
+                        scheduleIndex--
+                        continue
                     }
                     lastDelta = lastStopSequence?.minus(prediction.stopSequence)
                     lastStopSequence = prediction.stopSequence
@@ -359,7 +364,8 @@ data class TripDetailsStopList(val stops: List<Entry>) {
             entry: WorkingEntry,
             alertsData: AlertsStreamDataResponse?,
             globalData: GlobalResponse,
-            trip: Trip
+            tripId: String,
+            directionId: Int
         ): Alert? {
             val entryTime = entry.prediction?.predictionTime ?: entry.schedule?.scheduleTime
             val entryRoute = entry.prediction?.routeId ?: entry.schedule?.routeId
@@ -371,11 +377,11 @@ data class TripDetailsStopList(val stops: List<Entry>) {
                 alert.isActive(entryTime) &&
                     alert.anyInformedEntity {
                         it.appliesTo(
-                            directionId = trip.directionId,
+                            directionId = directionId,
                             routeId = entryRoute,
                             routeType = entryRouteType,
                             stopId = entry.stopId,
-                            tripId = trip.id
+                            tripId = tripId
                         )
                     } &&
                     // there's no UI yet for secondary alerts in trip details