Stabilize iOS/watchOS/tvOS apps and add cross-platform audit remediation

iphone/Werkout_ios/Extensions.swift

@@ -9,6 +9,67 @@ import Foundation
 import UIKit
 import SwiftUI
 
+private enum DateFormatterCache {
+    static let lock = NSLock()
+
+    static let serverDateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssX"
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter
+    }()
+
+    static let plannedDateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyy-MM-dd"
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter
+    }()
+
+    static let weekDayFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "EEE"
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter
+    }()
+
+    static let monthFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "MMM"
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter
+    }()
+
+    static let dayFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "d"
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        return formatter
+    }()
+
+    static func withLock<T>(_ block: () -> T) -> T {
+        lock.lock()
+        defer { lock.unlock() }
+        return block()
+    }
+}
+
+private enum DurationFormatterCache {
+    static let lock = NSLock()
+    static let formatter: DateComponentsFormatter = {
+        let formatter = DateComponentsFormatter()
+        formatter.allowedUnits = [.hour, .minute, .second, .nanosecond]
+        return formatter
+    }()
+
+    static func string(from seconds: Double, style: DateComponentsFormatter.UnitsStyle) -> String {
+        lock.lock()
+        defer { lock.unlock() }
+        formatter.unitsStyle = style
+        return formatter.string(from: seconds) ?? ""
+    }
+}
+
 extension Dictionary {
     func percentEncoded() -> Data? {
         map { key, value in
@@ -34,25 +95,23 @@ extension CharacterSet {
 
 extension Date {
     var timeFormatForUpload: String {
-        let isoFormatter = DateFormatter()
-        isoFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssX"
-        return isoFormatter.string(from: self)
+        DateFormatterCache.withLock {
+            DateFormatterCache.serverDateFormatter.string(from: self)
+        }
     }
 }
 
 extension String {
     var dateFromServerDate: Date? {
-        let df = DateFormatter()
-        df.dateFormat = "yyyy-MM-dd'T'HH:mm:ssX"
-        df.locale = Locale(identifier: "en_US_POSIX")
-        return df.date(from: self)
+        DateFormatterCache.withLock {
+            DateFormatterCache.serverDateFormatter.date(from: self)
+        }
     }
     
     var plannedDate: Date? {
-        let df = DateFormatter()
-        df.dateFormat = "yyyy-MM-dd"
-        df.locale = Locale(identifier: "en_US_POSIX")
-        return df.date(from: self)
+        DateFormatterCache.withLock {
+            DateFormatterCache.plannedDateFormatter.date(from: self)
+        }
     }
 }
 
@@ -66,31 +125,27 @@ extension Date {
     }
     
     var formatForPlannedWorkout: String {
-        let df = DateFormatter()
-        df.dateFormat = "yyyy-MM-dd"
-        df.locale = Locale(identifier: "en_US_POSIX")
-        return df.string(from: self)
+        DateFormatterCache.withLock {
+            DateFormatterCache.plannedDateFormatter.string(from: self)
+        }
     }
     
     var weekDay: String {
-        let dateFormatter = DateFormatter()
-        dateFormatter.dateFormat = "EEE"
-        let weekDay = dateFormatter.string(from: self)
-        return weekDay
+        DateFormatterCache.withLock {
+            DateFormatterCache.weekDayFormatter.string(from: self)
+        }
     }
     
     var monthString: String {
-        let dateFormatter = DateFormatter()
-        dateFormatter.dateFormat = "MMM"
-        let weekDay = dateFormatter.string(from: self)
-        return weekDay
+        DateFormatterCache.withLock {
+            DateFormatterCache.monthFormatter.string(from: self)
+        }
     }
     
     var dateString: String {
-        let dateFormatter = DateFormatter()
-        dateFormatter.dateFormat = "d"
-        let weekDay = dateFormatter.string(from: self)
-        return weekDay
+        DateFormatterCache.withLock {
+            DateFormatterCache.dayFormatter.string(from: self)
+        }
     }
 }
 
@@ -116,10 +171,7 @@ extension Double {
      10000.asString(style: .brief)       // 2hr 46min 40sec
      */
     func asString(style: DateComponentsFormatter.UnitsStyle) -> String {
-        let formatter = DateComponentsFormatter()
-        formatter.allowedUnits = [.hour, .minute, .second, .nanosecond]
-        formatter.unitsStyle = style
-        return formatter.string(from: self) ?? ""
+        DurationFormatterCache.string(from: self, style: style)
     }
 }