Prevent Automatic Dosing with Future Glucose

Loop/Managers/LoopDataManager.swift

@@ -1130,6 +1130,7 @@ extension LoopDataManager {
     ///     - LoopError.missingDataError
     ///     - LoopError.configurationError
     ///     - LoopError.glucoseTooOld
+    ///     - LoopError.invalidFutureGlucose
     ///     - LoopError.pumpDataTooOld
     fileprivate func predictGlucose(
         startingAt startingGlucoseOverride: GlucoseValue? = nil,
@@ -1156,6 +1157,10 @@ extension LoopDataManager {
             throw LoopError.glucoseTooOld(date: glucose.startDate)
         }
 
+        guard lastGlucoseDate.timeIntervalSince(now()) <= LoopCoreConstants.futureGlucoseDataInterval else {
+            throw LoopError.invalidFutureGlucose(date: lastGlucoseDate)
+        }
+
         guard now().timeIntervalSince(pumpStatusDate) <= LoopCoreConstants.inputDataRecencyInterval else {
             throw LoopError.pumpDataTooOld(date: pumpStatusDate)
         }
@@ -1390,6 +1395,7 @@ extension LoopDataManager {
     /// - Throws:
     ///     - LoopError.missingDataError
     ///     - LoopError.glucoseTooOld
+    ///     - LoopError.invalidFutureGlucose
     ///     - LoopError.pumpDataTooOld
     ///     - LoopError.configurationError
     fileprivate func recommendBolusValidatingDataRecency<Sample: GlucoseValue>(forPrediction predictedGlucose: [Sample],
@@ -1405,6 +1411,10 @@ extension LoopDataManager {
             throw LoopError.glucoseTooOld(date: glucose.startDate)
         }
 
+        guard lastGlucoseDate.timeIntervalSince(now()) <= LoopCoreConstants.inputDataRecencyInterval else {
+            throw LoopError.invalidFutureGlucose(date: lastGlucoseDate)
+        }
+
         guard now().timeIntervalSince(pumpStatusDate) <= LoopCoreConstants.inputDataRecencyInterval else {
             throw LoopError.pumpDataTooOld(date: pumpStatusDate)
         }
@@ -1516,6 +1526,7 @@ extension LoopDataManager {
     /// - Throws:
     ///     - LoopError.configurationError
     ///     - LoopError.glucoseTooOld
+    ///     - LoopError.invalidFutureGlucose
     ///     - LoopError.missingDataError
     ///     - LoopError.pumpDataTooOld
     private func updatePredictedGlucoseAndRecommendedDose(with dosingDecision: StoredDosingDecision) -> (StoredDosingDecision, LoopError?) {
@@ -1539,6 +1550,10 @@ extension LoopDataManager {
             errors.append(.glucoseTooOld(date: glucose.startDate))
         }
 
+        if glucose.startDate.timeIntervalSince(startDate) > LoopCoreConstants.inputDataRecencyInterval {
+            errors.append(.invalidFutureGlucose(date: glucose.startDate))
+        }
+
         let pumpStatusDate = doseStore.lastAddedPumpData
 
         if startDate.timeIntervalSince(pumpStatusDate) > LoopCoreConstants.inputDataRecencyInterval {

Loop/Models/LoopError.swift

@@ -89,6 +89,9 @@ enum LoopError: Error {
     // Glucose data is too old to perform action
     case glucoseTooOld(date: Date)
 
+    // Glucose data is in the future
+    case invalidFutureGlucose(date: Date)
+
     // Pump data is too old to perform action
     case pumpDataTooOld(date: Date)
 
@@ -120,6 +123,8 @@ extension LoopError {
             return "missingDataError"
         case .glucoseTooOld:
             return "glucoseTooOld"
+        case .invalidFutureGlucose:
+            return "invalidFutureGlucose"
         case .pumpDataTooOld:
             return "pumpDataTooOld"
         case .recommendationExpired:
@@ -142,6 +147,8 @@ extension LoopError {
             details["detail"] = detail.rawValue
         case .glucoseTooOld(let date):
             details["date"] = StoredDosingDecisionIssue.description(for: date)
+        case .invalidFutureGlucose(let date):
+            details["date"] = StoredDosingDecisionIssue.description(for: date)
         case .pumpDataTooOld(let date):
             details["date"] = StoredDosingDecisionIssue.description(for: date)
         case .recommendationExpired(let date):
@@ -183,6 +190,9 @@ extension LoopError: LocalizedError {
         case .glucoseTooOld(let date):
             let minutes = formatter.string(from: -date.timeIntervalSinceNow) ?? ""
             return String(format: NSLocalizedString("Glucose data is %1$@ old", comment: "The error message when glucose data is too old to be used. (1: glucose data age in minutes)"), minutes)
+        case .invalidFutureGlucose(let date):
+            let minutes = formatter.string(from: -date.timeIntervalSinceNow) ?? ""
+            return String(format: NSLocalizedString("Invalid glucose reading with a timestamp that is %1$@ in the future", comment: "The error message when glucose data is in the future. (1: glucose data time in future in minutes)"), minutes)
         case .pumpDataTooOld(let date):
             let minutes = formatter.string(from: -date.timeIntervalSinceNow) ?? ""
             return String(format: NSLocalizedString("Pump data is %1$@ old", comment: "The error message when pump data is too old to be used. (1: pump data age in minutes)"), minutes)

Loop/View Models/BolusEntryViewModel.swift

@@ -76,6 +76,7 @@ final class BolusEntryViewModel: ObservableObject {
         case predictedGlucoseBelowSuspendThreshold(suspendThreshold: HKQuantity)
         case glucoseBelowTarget
         case staleGlucoseData
+        case futureGlucoseData
         case stalePumpData
     }
 
@@ -673,6 +674,8 @@ final class BolusEntryViewModel: ObservableObject {
             switch error {
             case LoopError.missingDataError(.glucose), LoopError.glucoseTooOld:
                 notice = .staleGlucoseData
+            case LoopError.invalidFutureGlucose:
+                notice = .futureGlucoseData
             case LoopError.pumpDataTooOld:
                 notice = .stalePumpData
             default:

Loop/Views/BolusEntryView.swift

@@ -334,6 +334,11 @@ struct BolusEntryView: View {
                 title: Text("No Recent Glucose Data", comment: "Title for bolus screen notice when glucose data is missing or stale"),
                 caption: Text("Enter a blood glucose from a meter for a recommended bolus amount.", comment: "Caption for bolus screen notice when glucose data is missing or stale")
             )
+        case .futureGlucoseData:
+            return WarningView(
+                title: Text("Invalid Future Glucose", comment: "Title for bolus screen notice when glucose data is in the future"),
+                caption: Text("Check your device time and/or remove any invalid data from Apple Health.", comment: "Caption for bolus screen notice when glucose data is in the future")
+            )
         case .stalePumpData:
             return WarningView(
                 title: Text("No Recent Pump Data", comment: "Title for bolus screen notice when pump data is missing or stale"),

LoopCore/LoopCoreConstants.swift

@@ -13,6 +13,9 @@ public enum LoopCoreConstants {
     /// The amount of time since a given date that input data should be considered valid
     public static let inputDataRecencyInterval = TimeInterval(minutes: 15)
 
+    /// The amount of time in the future a glucose value should be considered valid
+    public static let futureGlucoseDataInterval = TimeInterval(minutes: 5)
+
     public static let defaultCarbAbsorptionTimes: CarbStore.DefaultAbsorptionTimes = (fast: .minutes(30), medium: .hours(3), slow: .hours(5))
 
     /// How much historical glucose to include in a dosing decision

LoopTests/ViewModels/BolusEntryViewModelTests.swift

@@ -348,6 +348,26 @@ class BolusEntryViewModelTests: XCTestCase {
         XCTAssertEqual(.stalePumpData, bolusEntryViewModel.activeNotice)
     }
 
+    func testUpdateRecommendedBolusThrowsGlucoseTooOld() async throws {
+        XCTAssertFalse(bolusEntryViewModel.isBolusRecommended)
+        delegate.loopState.bolusRecommendationError = LoopError.glucoseTooOld(date: now)
+        await bolusEntryViewModel.update()
+        XCTAssertFalse(bolusEntryViewModel.isBolusRecommended)
+        let recommendedBolus = bolusEntryViewModel.recommendedBolus
+        XCTAssertNil(recommendedBolus)
+        XCTAssertEqual(.staleGlucoseData, bolusEntryViewModel.activeNotice)
+    }
+
+    func testUpdateRecommendedBolusThrowsInvalidFutureGlucose() async throws {
+        XCTAssertFalse(bolusEntryViewModel.isBolusRecommended)
+        delegate.loopState.bolusRecommendationError = LoopError.invalidFutureGlucose(date: now)
+        await bolusEntryViewModel.update()
+        XCTAssertFalse(bolusEntryViewModel.isBolusRecommended)
+        let recommendedBolus = bolusEntryViewModel.recommendedBolus
+        XCTAssertNil(recommendedBolus)
+        XCTAssertEqual(.futureGlucoseData, bolusEntryViewModel.activeNotice)
+    }
+
     func testUpdateRecommendedBolusThrowsOtherError() async throws {
         XCTAssertFalse(bolusEntryViewModel.isBolusRecommended)
         delegate.loopState.bolusRecommendationError = LoopError.pumpSuspended