al borrar el buscador sigue funcionando

ContactsApp/ContactsViewController.swift

@@ -14,6 +14,7 @@ class ContactsViewController: UIViewController {
     @IBOutlet weak var searchBar: UISearchBar!
     @IBOutlet weak var contactsTable: UITableView!
     var contactStructArray = [ContactStruct]()
+    var contactAux = [ContactStruct]()
     var contactStruct : ContactStruct?
     let contactStore = CNContactStore()
     
@@ -27,6 +28,7 @@ class ContactsViewController: UIViewController {
     }
     
     func importContacts() {
+        self.contactStructArray = []
         let keys = [CNContactFormatter.descriptorForRequiredKeys(for: .fullName), CNContactEmailAddressesKey, CNContactPhoneNumbersKey, CNContactImageDataKey] as [Any]
         let request = CNContactFetchRequest( keysToFetch: keys as! [CNKeyDescriptor])
         request.sortOrder = CNContactSortOrder.givenName
@@ -50,10 +52,10 @@ class ContactsViewController: UIViewController {
                         auxLetter = String(contact.givenName.prefix(1)) //auxLetter tiene la primera letra del nombre
                         isNotTheFirst = true //la siguiente vez que las letras no sean iguales guardara en el array
                     }
-
                 }
             }
             self.contactStructArray.append(ContactStruct(isExpanded: true, contacts: contacts, letter: auxLetter)) //agregamos el ultimo nombre
+            self.contactAux = self.contactStructArray
         }
         catch {
             print("unable to fetch contacts")
@@ -152,21 +154,26 @@ extension ContactsViewController: UISearchBarDelegate, UISearchDisplayDelegate,
     }
     
     func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
-        importContacts()
+        contactStructArray = contactAux
     }
     
     func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
         var foundContacts = [ContactStruct]()
         
         if searchText == "" {
-            importContacts()
+            contactStructArray = contactAux
             contactsTable.reloadData()
         } else {
-            for indexContact in contactStructArray.indices{
-                let contactFound = contactStructArray[indexContact].contacts.filter({$0.givenName.lowercased().contains(searchText.lowercased())})
+            for indexContact in contactAux.indices{
+                let contactFound = contactAux[indexContact].contacts.filter(
+                    {
+                    let fullName = "\($0.givenName) \($0.familyName)"
+                    return fullName.lowercased().contains(searchText.lowercased())
+                    }
+                )
                 
                 if !contactFound.isEmpty {
-                    foundContacts.append(ContactStruct(isExpanded: true, contacts: contactFound, letter: contactStructArray[indexContact].letter))
+                    foundContacts.append(ContactStruct(isExpanded: true, contacts: contactFound, letter: contactAux[indexContact].letter))
                 }
             }
             contactStructArray = foundContacts