Fix crash when user taps tab key on external keyboard (#2205)

* Fix crash when user taps tab key on external keyboard

* Fix CI Xcode version

* Address comments and fix warning

.github/workflows/ci.yml

@@ -11,9 +11,12 @@ jobs:
     runs-on: macOS-latest
     strategy:
       matrix:
-        destination: ['platform=iOS Simulator,OS=14.4,name=iPhone 11']
+        destination: ['platform=iOS Simulator,OS=15.2,name=iPhone 11']
 
     steps:
     - uses: actions/checkout@v2
+    - uses: maxim-lobanov/setup-xcode@v1
+      with:
+        xcode-version: '13.2.1'
     - name: Build and test
       run: set -o pipefail && xcodebuild -project Eureka.xcodeproj -scheme 'Eureka' -sdk 'iphonesimulator' -destination "${{ matrix.destination }}" -configuration Debug test | xcpretty

Source/Core/Cell.swift

@@ -52,7 +52,7 @@ open class BaseCell: UITableViewCell, BaseCellType {
             if let formVC = responder as? FormViewController {
               return formVC
             }
-            responder = (responder as? UIResponder)?.next
+            responder = responder?.next
         }
         return nil
     }

Source/Core/Core.swift

@@ -1088,6 +1088,26 @@ extension FormViewController {
         navigateTo(direction: .down)
     }
 
+    open override func pressesBegan(_ presses: Set<UIPress>, with event: UIPressesEvent?) {
+        var didHandleEvent = false
+        for press in presses {
+            guard let key = press.key,
+                key.keyCode == .keyboardTab,
+                !key.modifierFlags.contains(.command) else { continue }
+            if key.modifierFlags.contains(.shift) {
+                navigateTo(direction: .up)
+            } else {
+                navigateTo(direction: .down)
+            }
+            didHandleEvent = true
+        }
+
+        if !didHandleEvent {
+            // Didn't handle this key press, so pass the event to the next responder.
+            super.pressesBegan(presses, with: event)
+        }
+    }
+
     public func navigateTo(direction: Direction) {
         guard let currentCell = tableView?.findFirstResponder()?.formCell() else { return }
         guard let currentIndexPath = tableView?.indexPath(for: currentCell) else { return }