Fix launch crash on non-string Nightscout treatment timestamps

LoopFollow/Controllers/Nightscout/CAge.swift

@@ -39,7 +39,11 @@ extension MainViewController {
                                    .withTime,
                                    .withDashSeparatorInDate,
                                    .withColonSeparatorInTime]
-        Storage.shared.cageInsertTime.value = formatter.date(from: lastCageString)?.timeIntervalSince1970 as! TimeInterval
+        guard let cageInsertTime = formatter.date(from: lastCageString)?.timeIntervalSince1970 else {
+            LogManager.shared.log(category: .nightscout, message: "updateCage: unparseable created_at '\(lastCageString)'")
+            return
+        }
+        Storage.shared.cageInsertTime.value = cageInsertTime
         if let cageTime = formatter.date(from: lastCageString)?.timeIntervalSince1970 {
             let now = dateTimeUtils.getNowTimeIntervalUTC()
             let secondsAgo = now - cageTime

LoopFollow/Controllers/Nightscout/DeviceStatusLoop.swift

@@ -64,9 +64,11 @@ extension MainViewController {
                 latestCOB = cobMetric
             }
 
-            if let predictdata = lastLoopRecord["predicted"] as? [String: AnyObject] {
-                let prediction = predictdata["values"] as! [Double]
-                Observable.shared.predictionText.value = Localizer.toDisplayUnits(String(Int(round(prediction.last!))))
+            if let predictdata = lastLoopRecord["predicted"] as? [String: AnyObject],
+               let prediction = predictdata["values"] as? [Double],
+               let lastPrediction = prediction.last
+            {
+                Observable.shared.predictionText.value = Localizer.toDisplayUnits(String(Int(round(lastPrediction))))
                 Observable.shared.predictionColor.value = .purple
                 if Storage.shared.downloadPrediction.value, previousLastLoopTime < lastLoopTime || predictionData.isEmpty {
                     predictionData.removeAll()
@@ -108,7 +110,9 @@ extension MainViewController {
                 Observable.shared.deviceRecBolus.value = nil
             }
             if let loopStatus = lastLoopRecord["recommendedTempBasal"] as? [String: AnyObject] {
-                if let tempBasalTime = formatter.date(from: (loopStatus["timestamp"] as! String))?.timeIntervalSince1970 {
+                if let tempBasalString = loopStatus["timestamp"] as? String,
+                   let tempBasalTime = formatter.date(from: tempBasalString)?.timeIntervalSince1970
+                {
                     var lastBGTime = lastLoopTime
                     if bgData.count > 0 {
                         lastBGTime = bgData[bgData.count - 1].date

LoopFollow/Controllers/Nightscout/DeviceStatusOpenAPS.swift

@@ -220,7 +220,9 @@ extension MainViewController {
             }
 
             if let loopStatus = lastLoopRecord["recommendedTempBasal"] as? [String: AnyObject] {
-                if let tempBasalTime = formatter.date(from: (loopStatus["timestamp"] as! String))?.timeIntervalSince1970 {
+                if let tempBasalString = loopStatus["timestamp"] as? String,
+                   let tempBasalTime = formatter.date(from: tempBasalString)?.timeIntervalSince1970
+                {
                     var lastBGTime = updatedTime ?? Date().timeIntervalSince1970
                     if bgData.count > 0 {
                         lastBGTime = bgData[bgData.count - 1].date

LoopFollow/Controllers/Nightscout/IAge.swift

@@ -44,7 +44,7 @@ extension MainViewController {
                                    .withDashSeparatorInDate,
                                    .withColonSeparatorInTime]
 
-        if let iageTime = formatter.date(from: (lastIageString as! String))?.timeIntervalSince1970 {
+        if let iageTime = formatter.date(from: lastIageString)?.timeIntervalSince1970 {
             Storage.shared.iageInsertTime.value = iageTime
             let now = dateTimeUtils.getNowTimeIntervalUTC()
             let secondsAgo = now - iageTime

LoopFollow/Controllers/Nightscout/SAge.swift

@@ -36,14 +36,18 @@ extension MainViewController {
             return
         }
         currentSage = data[0]
-        var lastSageString = data[0].created_at
+        let lastSageString = data[0].created_at
 
         let formatter = ISO8601DateFormatter()
         formatter.formatOptions = [.withFullDate,
                                    .withTime,
                                    .withDashSeparatorInDate,
                                    .withColonSeparatorInTime]
-        Storage.shared.sageInsertTime.value = formatter.date(from: lastSageString)?.timeIntervalSince1970 as! TimeInterval
+        guard let sageInsertTime = formatter.date(from: lastSageString)?.timeIntervalSince1970 else {
+            LogManager.shared.log(category: .nightscout, message: "updateSage: unparseable created_at '\(lastSageString)'")
+            return
+        }
+        Storage.shared.sageInsertTime.value = sageInsertTime
 
         // -- Auto-snooze CGM start ────────────────────────────────────────────────
         let now = Date()
@@ -62,7 +66,7 @@ extension MainViewController {
             }
         }
 
-        if let sageTime = formatter.date(from: (lastSageString as! String))?.timeIntervalSince1970 {
+        if let sageTime = formatter.date(from: lastSageString)?.timeIntervalSince1970 {
             let now = dateTimeUtils.getNowTimeIntervalUTC()
             let secondsAgo = now - sageTime
 

LoopFollow/Controllers/Nightscout/Treatments/Bolus.swift

@@ -11,16 +11,7 @@ extension MainViewController {
         var lastFoundIndex = 0
 
         for currentEntry in entries.reversed() {
-            var bolusDate: String
-            if currentEntry["timestamp"] != nil {
-                bolusDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                bolusDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
-            guard let parsedDate = NightscoutUtils.parseDate(bolusDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let bolus = currentEntry["insulin"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970

LoopFollow/Controllers/Nightscout/Treatments/Carbs.swift

@@ -13,18 +13,9 @@ extension MainViewController {
         var lastFoundSmb = 0
 
         for currentEntry in entries.reversed() {
-            var carbDate: String
-            if currentEntry["timestamp"] != nil {
-                carbDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                carbDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
             let absorptionTime = currentEntry["absorptionTime"] as? Int ?? 0
 
-            guard let parsedDate = NightscoutUtils.parseDate(carbDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let carbs = currentEntry["carbs"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970

LoopFollow/Controllers/Nightscout/Treatments/Notes.swift

@@ -13,16 +13,7 @@ extension MainViewController {
         for currentEntry in entries.reversed() {
             guard let currentEntry = currentEntry as? [String: AnyObject] else { continue }
 
-            var date: String
-            if currentEntry["timestamp"] != nil {
-                date = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                date = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
-            if let parsedDate = NightscoutUtils.parseDate(date) {
+            if let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry) {
                 let dateTimeStamp = parsedDate.timeIntervalSince1970
                 let sgv = findNearestBGbyTime(needle: dateTimeStamp, haystack: bgData, startingIndex: lastFoundIndex)
                 lastFoundIndex = sgv.foundIndex

LoopFollow/Controllers/Nightscout/Treatments/SMB.swift

@@ -10,16 +10,7 @@ extension MainViewController {
         var lastFoundIndex = 0
 
         for currentEntry in entries.reversed() {
-            var bolusDate: String
-            if currentEntry["timestamp"] != nil {
-                bolusDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                bolusDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
-            guard let parsedDate = NightscoutUtils.parseDate(bolusDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let bolus = currentEntry["insulin"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970

LoopFollow/Helpers/NightscoutUtils.swift

@@ -274,6 +274,32 @@ class NightscoutUtils {
         task.resume()
     }
 
+    /// Effective time of a Nightscout treatment: `timestamp` when present, otherwise `created_at`.
+    /// Uploaders disagree on the value's type (ISO 8601 string, epoch milliseconds, or JSON `null`),
+    /// so never force-cast it; an unreadable value yields `nil` and the entry is skipped.
+    static func treatmentDate(from entry: [String: AnyObject]) -> Date? {
+        for key in ["timestamp", "created_at"] {
+            guard let value = entry[key], !(value is NSNull) else { continue }
+            return parseDateValue(value)
+        }
+        return nil
+    }
+
+    static func parseDateValue(_ value: Any) -> Date? {
+        switch value {
+        case let string as String:
+            return parseDate(string)
+        case let number as NSNumber:
+            // Booleans are NSNumbers too; they are never a date.
+            if CFGetTypeID(number) == CFBooleanGetTypeID() { return nil }
+            let raw = number.doubleValue
+            // Epoch milliseconds are ~1e12; epoch seconds are ~1e9.
+            return Date(timeIntervalSince1970: raw > 1e11 ? raw / 1000 : raw)
+        default:
+            return nil
+        }
+    }
+
     static func parseDate(_ rawString: String) -> Date? {
         var mutableDate = rawString
 

LoopFollow/Stats/StatsDataFetcher.swift

@@ -201,16 +201,7 @@ class StatsDataFetcher {
         var lastFoundIndex = 0
 
         for currentEntry in bolusEntries.reversed() {
-            var bolusDate: String
-            if currentEntry["timestamp"] != nil {
-                bolusDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                bolusDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
-            guard let parsedDate = NightscoutUtils.parseDate(bolusDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let bolus = currentEntry["insulin"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970
@@ -250,16 +241,7 @@ class StatsDataFetcher {
         var lastFoundIndex = 0
 
         for currentEntry in smbEntries.reversed() {
-            var bolusDate: String
-            if currentEntry["timestamp"] != nil {
-                bolusDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                bolusDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
-            guard let parsedDate = NightscoutUtils.parseDate(bolusDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let bolus = currentEntry["insulin"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970
@@ -296,18 +278,9 @@ class StatsDataFetcher {
         var lastFoundBolus = 0
 
         for currentEntry in carbEntries.reversed() {
-            var carbDate: String
-            if currentEntry["timestamp"] != nil {
-                carbDate = currentEntry["timestamp"] as! String
-            } else if currentEntry["created_at"] != nil {
-                carbDate = currentEntry["created_at"] as! String
-            } else {
-                continue
-            }
-
             let absorptionTime = currentEntry["absorptionTime"] as? Int ?? 0
 
-            guard let parsedDate = NightscoutUtils.parseDate(carbDate),
+            guard let parsedDate = NightscoutUtils.treatmentDate(from: currentEntry),
                   let carbs = currentEntry["carbs"] as? Double else { continue }
 
             let dateTimeStamp = parsedDate.timeIntervalSince1970

Tests/NightscoutTreatmentDateTests.swift

@@ -0,0 +1,53 @@
+// LoopFollow
+// NightscoutTreatmentDateTests.swift
+
+import Foundation
+@testable import LoopFollow
+import Testing
+
+struct NightscoutTreatmentDateTests {
+    private typealias Entry = [String: AnyObject]
+
+    private let expected = Date(timeIntervalSince1970: 1_787_000_000)
+
+    @Test("parses an ISO 8601 timestamp string")
+    func parsesStringTimestamp() {
+        let entry: Entry = ["timestamp": "2026-08-17T20:53:20.000Z" as AnyObject]
+        #expect(NightscoutUtils.treatmentDate(from: entry) == expected)
+    }
+
+    @Test("falls back to created_at when timestamp is missing")
+    func fallsBackToCreatedAt() {
+        let entry: Entry = ["created_at": "2026-08-17T20:53:20Z" as AnyObject]
+        #expect(NightscoutUtils.treatmentDate(from: entry) == expected)
+    }
+
+    @Test("falls back to created_at when timestamp is JSON null")
+    func nullTimestampFallsBack() {
+        let entry: Entry = [
+            "timestamp": NSNull(),
+            "created_at": "2026-08-17T20:53:20Z" as AnyObject,
+        ]
+        #expect(NightscoutUtils.treatmentDate(from: entry) == expected)
+    }
+
+    @Test("accepts epoch milliseconds and seconds")
+    func parsesNumericTimestamp() {
+        let millis: Entry = ["timestamp": NSNumber(value: 1_787_000_000_000)]
+        let seconds: Entry = ["timestamp": NSNumber(value: 1_787_000_000)]
+        #expect(NightscoutUtils.treatmentDate(from: millis) == expected)
+        #expect(NightscoutUtils.treatmentDate(from: seconds) == expected)
+    }
+
+    @Test("returns nil instead of trapping on unsupported values")
+    func unsupportedValuesReturnNil() {
+        let bool: Entry = ["timestamp": NSNumber(value: true)]
+        let array: Entry = ["timestamp": ["2026-08-17T20:53:20Z"] as AnyObject]
+        let garbage: Entry = ["timestamp": "not a date" as AnyObject]
+        let empty: Entry = [:]
+        #expect(NightscoutUtils.treatmentDate(from: bool) == nil)
+        #expect(NightscoutUtils.treatmentDate(from: array) == nil)
+        #expect(NightscoutUtils.treatmentDate(from: garbage) == nil)
+        #expect(NightscoutUtils.treatmentDate(from: empty) == nil)
+    }
+}