Fix compile error on Xcode 13 / iOS 15 SDK cause by an optionality change in one of the CBCharacteristic properties. (#260)

Also updates Info.plist to have the correct privacy notice for using Bluetooth

Author: nbrooke

Bluejay/Bluejay/CharacteristicIdentifier.swift

@@ -17,9 +17,16 @@ public struct CharacteristicIdentifier {
     /// The `CBUUID` of this characteristic.
     public let uuid: CBUUID
 
-    /// Create a `CharacteristicIdentifier` using a `CBCharacterstic`.
-    public init(_ cbCharacteristic: CBCharacteristic) {
-        self.service = ServiceIdentifier(uuid: cbCharacteristic.service.uuid)
+    /// Create a `CharacteristicIdentifier` using a `CBCharacterstic`. Creation will fail if the "service" property of the CBCharacteristic is nil.
+    /// Note: It isn't documented in CoreBluetooth under what circumstances that property might be nil, but it seems like it should almost never happen.
+    public init?(_ cbCharacteristic: CBCharacteristic) {
+        let optionalService: CBService? = cbCharacteristic.service // became optional with iOS 15 SDK, do a little dance to make it always optional so code below should compile on Xcode 12 or 13
+
+        guard let service = optionalService else {
+            return nil
+        }
+
+        self.service = ServiceIdentifier(uuid: service.uuid)
         self.uuid = cbCharacteristic.uuid
     }
 
@@ -46,7 +53,8 @@ public struct CharacteristicIdentifier {
 
     /// Check equality between a `CharacteristicIdentifier` and a `CBCharacterstic`.
     public static func == (lhs: CharacteristicIdentifier, rhs: CBCharacteristic) -> Bool {
-        return (lhs.uuid == rhs.uuid) && (lhs.service.uuid == rhs.service.uuid)
+        let optionalService: CBService? = rhs.service // became optional with iOS 15 SDK, do a little dance to make it always optional so code below should compile on Xcode 12 or 13
+        return (lhs.uuid == rhs.uuid) && (lhs.service.uuid == optionalService?.uuid)
     }
 }
 

Bluejay/Bluejay/Peripheral.swift

@@ -298,12 +298,15 @@ extension Peripheral: CBPeripheralDelegate {
 
     /// Captures CoreBluetooth's did receive a notification/value from a characteristic event and pass it to Bluejay's queue for processing.
     public func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
-        let characteristicIdentifier = CharacteristicIdentifier(characteristic)
+        guard let characteristicIdentifier = CharacteristicIdentifier(characteristic) else {
+            debugLog("Received value update for characteristic (\(characteristic.uuid.uuidString) without a valid service. Update will be ignored")
+            return
+        }
 
         guard let listener = listeners[characteristicIdentifier], let listenCallback = listener.0 else {
             if delegate.isReading(characteristic: characteristicIdentifier) {
                 handle(event: .didReadCharacteristic(characteristic, characteristic.value ?? Data()), error: error as NSError?)
-            } else if delegate.willEndListen(on: CharacteristicIdentifier(characteristic)) {
+            } else if delegate.willEndListen(on: characteristicIdentifier) {
                 debugLog("""
                     Received read event with value \(String(data: characteristic.value ?? Data(), encoding: .utf8) ?? "") \
                     on characteristic \(characteristic.debugDescription), \

Bluejay/BluejayHeartSensorDemo/Info.plist

@@ -43,5 +43,7 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
+	<key>NSBluetoothAlwaysUsageDescription</key>
+	<string>Connect to the test device</string>
 </dict>
 </plist>