fixed crash

Example/UBottomSheet/Cells/EmbeddedCell.swift

@@ -45,9 +45,10 @@ class EmbeddedCell: UITableViewCell, UICollectionViewDataSource, UICollectionVie
     }
 
     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
-        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "HorizontalCell", for: indexPath) as! HorizontalCell
+        guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "HorizontalCell", for: indexPath) as? HorizontalCell else {
+            return UICollectionViewCell()
+        }
         cell.configure(with: items[indexPath.item])
         return cell
     }
-
 }

Example/UBottomSheet/DataSource/MyDataSource.swift

@@ -11,10 +11,10 @@ import UBottomSheet
 
 class MyDataSource: UBottomSheetCoordinatorDataSource {
     func sheetPositions(_ availableHeight: CGFloat) -> [CGFloat] {
-        return [0.2, 0.4, 0.6, 0.8].map{$0*availableHeight}
+        return [0.2, 0.4, 0.6, 0.8].map{ $0 * availableHeight }
     }
 
     func initialPosition(_ availableHeight: CGFloat) -> CGFloat {
-        return availableHeight*0.4
+        return availableHeight * 0.4
     }
 }

Example/UBottomSheet/DataSource/PullToDismissDataSource.swift

@@ -11,10 +11,10 @@ import UBottomSheet
 
 class PullToDismissDataSource: UBottomSheetCoordinatorDataSource {
     func sheetPositions(_ availableHeight: CGFloat) -> [CGFloat] {
-        return [0.5, 1.1].map{$0*availableHeight} /// Trick is to set bottom position to any value more than available height such as 1.1*availableHeight
+        return [0.5, 1.1].map{ $0 * availableHeight } /// Trick is to set bottom position to any value more than available height such as 1.1*availableHeight
     }
 
     func initialPosition(_ availableHeight: CGFloat) -> CGFloat {
-        return availableHeight*0.5
+        return availableHeight * 0.5
     }
 }

Example/UBottomSheet/ViewControllers/AppleMapsSheetViewController/AppleMapsSheetViewController.swift

@@ -73,10 +73,14 @@ extension AppleMapsSheetViewController: UITableViewDelegate, UITableViewDataSour
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         switch indexPath.section {
         case 0:
-            let cell = tableView.dequeueReusableCell(withIdentifier: "EmbeddedCell", for: indexPath) as! EmbeddedCell
+            guard let cell = tableView.dequeueReusableCell(withIdentifier: "EmbeddedCell", for: indexPath) as? EmbeddedCell else {
+                return UITableViewCell()
+            }
             return cell
         default:
-            let cell = tableView.dequeueReusableCell(withIdentifier: "MapItemCell", for: indexPath) as! MapItemCell
+            let cell = tableView.dequeueReusableCell(withIdentifier: "MapItemCell", for: indexPath) as? MapItemCell else {
+                return UITableViewCell()
+            }
             let title: String
             let subtitle: String
             switch indexPath.row {
@@ -102,9 +106,10 @@ extension AppleMapsSheetViewController: UITableViewDelegate, UITableViewDataSour
 
         switch indexPath.row {
         case 0:
-            let sc = UBottomSheetCoordinator(parent: sheetCoordinator!.parent)
+            guard let sheetCoordinator = sheetCoordinator else { return }
+            let sc = UBottomSheetCoordinator(parent: sheetCoordinator.parent)
             vc.sheetCoordinator = sc
-            sc.addSheet(vc, to: sheetCoordinator!.parent)
+            sc.addSheet(vc, to: sheetCoordinator.parent)
         case 1:
             vc.sheetCoordinator = sheetCoordinator
             sheetCoordinator?.addSheetChild(vc)

Example/UBottomSheet/ViewControllers/ListViewController/ListViewController.swift

@@ -53,7 +53,9 @@ extension ListViewController: UITableViewDelegate, UITableViewDataSource{
     }
 
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
-        let cell = tableView.dequeueReusableCell(withIdentifier: "MapItemCell", for: indexPath) as! MapItemCell
+        guard let cell = tableView.dequeueReusableCell(withIdentifier: "MapItemCell", for: indexPath) as? MapItemCell else {
+            return UITableViewCell()
+        }
         let title: String
         let subtitle: String
         switch indexPath.row {
@@ -76,9 +78,10 @@ extension ListViewController: UITableViewDelegate, UITableViewDataSource{
         let vc = LabelViewController()
         switch indexPath.row {
         case 0:
-            let sc = UBottomSheetCoordinator(parent: sheetCoordinator!.parent)
+            guard let sheetCoordinator = sheetCoordinator else { return }
+            let sc = UBottomSheetCoordinator(parent: sheetCoordinator.parent)
             vc.sheetCoordinator = sc
-            sc.addSheet(vc, to: sheetCoordinator!.parent)
+            sc.addSheet(vc, to: sheetCoordinator.parent)
         case 1:
             vc.sheetCoordinator = sheetCoordinator
             sheetCoordinator?.addSheetChild(vc)

Example/UBottomSheet/ViewControllers/MapsViewController/MapsViewController.swift

@@ -10,7 +10,7 @@ import UIKit
 import UBottomSheet
 
 class MapsViewController: UIViewController {
-    var sheetCoordinator: UBottomSheetCoordinator!
+    var sheetCoordinator: UBottomSheetCoordinator?
     var backView: PassThroughView?
 
     override func viewDidLoad() {
@@ -36,21 +36,21 @@ class MapsViewController: UIViewController {
 
     }
 
-    private func addBackDimmingBackView(below container: UIView){
-        backView = PassThroughView()
-        self.view.insertSubview(backView!, belowSubview: container)
-        backView!.translatesAutoresizingMaskIntoConstraints = false
-        backView!.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
-        backView!.bottomAnchor.constraint(equalTo: container.topAnchor, constant: 10).isActive = true
-        backView!.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
-        backView!.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
+    private func addBackDimmingBackView(below container: UIView) {
+        guard let backView = PassThroughView() else { return }
+        self.view.insertSubview(backView, belowSubview: container)
+        backView.translatesAutoresizingMaskIntoConstraints = false
+        backView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
+        backView.bottomAnchor.constraint(equalTo: container.topAnchor, constant: 10).isActive = true
+        backView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
+        backView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
     }
 }
 
-extension MapsViewController: UBottomSheetCoordinatorDelegate{
+extension MapsViewController: UBottomSheetCoordinatorDelegate {
 
     func bottomSheet(_ container: UIView?, didPresent state: SheetTranslationState) {
-//        self.addBackDimmingBackView(below: container!)
+//        self.addBackDimmingBackView(below: container!) // if later uncommented, remove the force unwrap and add a guard let for the container
         self.sheetCoordinator.addDropShadowIfNotExist()
         self.handleState(state)
     }

Example/UBottomSheet/ViewControllers/SimpleViewController/SimpleViewController.swift

@@ -10,9 +10,9 @@ import UIKit
 import UBottomSheet
 
 class SimpleViewController: UIViewController {
-    var sheetCoordinator: UBottomSheetCoordinator!
+    var sheetCoordinator: UBottomSheetCoordinator?
 
-    var sheetVC: DraggableItem!
+    var sheetVC: DraggableItem?
     var useNavController = false
     var dataSource: UBottomSheetCoordinatorDataSource?
 
@@ -25,10 +25,10 @@ class SimpleViewController: UIViewController {
 
         guard sheetCoordinator == nil else {return}
         sheetCoordinator = UBottomSheetCoordinator(parent: self)
-        if dataSource != nil{
-            sheetCoordinator.dataSource = dataSource!
+        if let dataSource = dataSource {
+            sheetCoordinator.dataSource = dataSource
         }
-        
+
         let vc: UIViewController
         if useNavController{
             vc = UINavigationController(rootViewController: sheetVC)

Sources/UBottomSheet/Classes/Extensions.swift

@@ -62,7 +62,8 @@ extension UIView {
 }
 
 extension Array where Element == CGFloat {
-    func nearest(to x: CGFloat) -> CGFloat {
-        return self.reduce(self.first!) { abs($1 - x) < abs($0 - x) ? $1 : $0 }
+    func nearest(to x: CGFloat) -> CGFloat? {
+        guard let first = first else { return nil }
+        return self.reduce(first) { abs($1 - x) < abs($0 - x) ? $1 : $0 }
     }
 }