Remove the search results predicate when the keyword is empty.

Author: jaclync

WooCommerce/Classes/ViewRelated/Coupons/CouponSearchUICommand.swift

@@ -83,7 +83,7 @@ final class CouponSearchUICommand: SearchUICommand {
         viewController.configure(.simple(message: message, image: .emptySearchResultsImage))
     }
 
-    func searchResultsPredicate(keyword: String) -> NSPredicate {
+    func searchResultsPredicate(keyword: String) -> NSPredicate? {
         NSPredicate(format: "ANY searchResults.keyword = %@", keyword)
     }
 }

WooCommerce/Classes/ViewRelated/Products/Edit Product/Linked Products List Selector/ProductListSelector/ProductListMultiSelectorSearchUICommand.swift

@@ -93,7 +93,7 @@ final class ProductListMultiSelectorSearchUICommand: NSObject, SearchUICommand {
         updateActionButton()
     }
 
-    func searchResultsPredicate(keyword: String) -> NSPredicate {
+    func searchResultsPredicate(keyword: String) -> NSPredicate? {
         NSPredicate(format: "ANY searchResults.keyword = %@", keyword)
     }
 }

WooCommerce/Classes/ViewRelated/Search/Order/OrderSearchUICommand.swift

@@ -94,7 +94,7 @@ final class OrderSearchUICommand: SearchUICommand {
         return keyword
     }
 
-    func searchResultsPredicate(keyword: String) -> NSPredicate {
+    func searchResultsPredicate(keyword: String) -> NSPredicate? {
         NSPredicate(format: "ANY searchResults.keyword = %@", keyword)
     }
 }

WooCommerce/Classes/ViewRelated/Search/Product/ProductSearchUICommand.swift

@@ -121,7 +121,10 @@ final class ProductSearchUICommand: SearchUICommand {
         }
     }
 
-    func searchResultsPredicate(keyword: String) -> NSPredicate {
+    func searchResultsPredicate(keyword: String) -> NSPredicate? {
+        guard keyword.isNotEmpty else {
+            return nil
+        }
         guard isSearchProductsBySKUEnabled else {
             return NSPredicate(format: "ANY searchResults.keyword = %@", keyword)
         }

WooCommerce/Classes/ViewRelated/Search/SearchUICommand.swift

@@ -101,8 +101,8 @@ protocol SearchUICommand {
     /// The predicate to fetch product search results based on the keyword.
     /// Called when a search API request is made for the keyword.
     /// - Parameter keyword: search query.
-    /// - Returns: predicate that is based on the search keyword.
-    func searchResultsPredicate(keyword: String) -> NSPredicate
+    /// - Returns: predicate that is based on the search keyword. When the keyword is empty, `nil` can be returned as an example use case.
+    func searchResultsPredicate(keyword: String) -> NSPredicate?
 }
 
 // MARK: - Default implementation

WooCommerce/Classes/ViewRelated/Search/SearchViewController.swift

@@ -431,7 +431,7 @@ private extension SearchViewController {
         // When the search query changes, also includes the original results predicate in addition to the search keyword.
         let keyword = searchUICommand.sanitizeKeyword(keyword)
         let searchResultsPredicate = searchUICommand.searchResultsPredicate(keyword: keyword)
-        let subpredicates = [resultsPredicate].compactMap { $0 } + [searchResultsPredicate]
+        let subpredicates = [resultsPredicate].compactMap { $0 } + [searchResultsPredicate].compactMap { $0 }
         resultsController.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: subpredicates)
 
         tableView.setContentOffset(.zero, animated: false)