fix(sync): wrap the start function in async dispatch

Author: Donald

ios/DeviceUpgrade.swift

@@ -35,38 +35,40 @@ class DeviceUpgrade {
     }
 
     func startUpgrade(resolver resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) {
-        self.upgradeResolver = resolve
-        self.upgradeRejecter = reject
-
-        guard let bleUuid = UUID(uuidString: bleId) else {
-            let error = NSError(domain: "", code: 200, userInfo: nil)
-            return reject("error", "failed to parse uuid", error);
-        }
-
-        guard let fileUrl = URL(string: fileURI) else {
-            let error = NSError(domain: "", code: 200, userInfo: nil)
-            return reject("error", "failed to parse file uri as url", error);
-        }
-
-        do {
-            let filehandle = try FileHandle(forReadingFrom: fileUrl)
-            let file = Data(filehandle.availableData)
-            filehandle.closeFile()
-
-            self.bleTransport = McuMgrBleTransport(bleUuid)
-            self.dfuManager = FirmwareUpgradeManager(transporter: self.bleTransport!, delegate: self)
-
-            let estimatedSwapTime: TimeInterval = options["estimatedSwapTime"] as! TimeInterval
-            let config = FirmwareUpgradeConfiguration(
-                estimatedSwapTime: estimatedSwapTime
-            )
-
-            self.dfuManager!.logDelegate = self.logDelegate
-            self.dfuManager!.mode = self.getMode();
-
-            try self.dfuManager!.start(data: file as Data, using: config)
-        } catch {
-            reject(error.localizedDescription, error.localizedDescription, error)
+        DispatchQueue.main.async {
+            self.upgradeResolver = resolve
+            self.upgradeRejecter = reject
+
+            guard let bleUuid = UUID(uuidString: bleId) else {
+                let error = NSError(domain: "", code: 200, userInfo: nil)
+                return reject("error", "failed to parse uuid", error);
+            }
+
+            guard let fileUrl = URL(string: fileURI) else {
+                let error = NSError(domain: "", code: 200, userInfo: nil)
+                return reject("error", "failed to parse file uri as url", error);
+            }
+
+            do {
+                let filehandle = try FileHandle(forReadingFrom: fileUrl)
+                let file = Data(filehandle.availableData)
+                filehandle.closeFile()
+
+                self.bleTransport = McuMgrBleTransport(bleUuid)
+                self.dfuManager = FirmwareUpgradeManager(transporter: self.bleTransport!, delegate: self)
+
+                let estimatedSwapTime: TimeInterval = options["estimatedSwapTime"] as! TimeInterval
+                let config = FirmwareUpgradeConfiguration(
+                    estimatedSwapTime: estimatedSwapTime
+                )
+
+                self.dfuManager!.logDelegate = self.logDelegate
+                self.dfuManager!.mode = self.getMode();
+
+                try self.dfuManager!.start(data: file as Data, using: config)
+            } catch {
+                reject(error.localizedDescription, error.localizedDescription, error)
+            }
         }
     }