Feat: adds clear function to HitsSource

Sources/InstantSearchCore/Hits/AnyHitsInteractor.swift

@@ -46,4 +46,6 @@ public protocol AnyHitsInteractor: AnyObject {
 
   func notifyQueryChanged()
   func process(_ error: Swift.Error, for query: Query)
+
+  func clear()
 }

Sources/InstantSearchCore/Hits/HitsInteractor.swift

@@ -100,6 +100,7 @@ public class HitsInteractor<Record: Codable>: AnyHitsInteractor {
     guard let hitsPageMap = paginator.pageMap, !paginator.isInvalidated else { return 0 }
 
     if isLastQueryEmpty && !settings.showItemsOnEmptyQuery {
+      clear()
       return 0
     } else {
       return hitsPageMap.count
@@ -150,6 +151,10 @@ public class HitsInteractor<Record: Codable>: AnyHitsInteractor {
 
     infiniteScrollingController.calculatePagesAndLoad(currentRow: rowIndex, offset: pageLoadOffset, pageMap: hitsPageMap)
   }
+
+  public func clear() {
+    paginator.clear()
+  }
 }
 
 public extension HitsInteractor {

Sources/InstantSearchCore/Pagination/Paginator.swift

@@ -35,4 +35,8 @@ class Paginator<Item> {
   public func invalidate() {
     isInvalidated = true
   }
+
+  public func clear() {
+    pageMap = nil
+  }
 }

Sources/InstantSearchSwiftUI/DataModel/HitsObservableController.swift

@@ -16,11 +16,12 @@ import InstantSearchTelemetry
   /// HitsController implementation adapted for usage with SwiftUI views
   @available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
   public class HitsObservableController<Hit: Codable>: ObservableObject, HitsController {
-    /// List of hits itemsto present
-    @Published public var hits: [Hit?]
+
+    /// List of hits items to present
+    @Published private(set) public var hits: [Hit?]
 
     /// The state ID to assign to the scrollview presenting the hits
-    @Published public var scrollID: UUID
+    @Published private(set) public var scrollID: UUID
 
     public var hitsSource: HitsInteractor<Hit>?
 

Sources/InstantSearchSwiftUI/View/HitsList.swift

@@ -71,13 +71,46 @@
   #if os(iOS)
     @available(iOS 13.0, tvOS 13.0, watchOS 7.0, *)
     struct HitsView_Previews: PreviewProvider {
+
+      struct PreviewRecord<Value: Codable>: Codable {
+        let objectID: ObjectID
+        let value: Value
+
+        init(_ value: Value, objectID: ObjectID = ObjectID(rawValue: UUID().uuidString)) {
+          self.value = value
+          self.objectID = objectID
+        }
+
+        static func withValue(_ value: Value) -> Self {
+          .init(value)
+        }
+      }
+
+      static let rawHits: Data = """
+          {
+            "hits": [
+              {
+              "objectID": "1",
+              "value": "h1"
+              },
+              {
+              "objectID": "2",
+              "value": "h2"
+              }
+            ]
+          }
+          """.data(using: .utf8)!
+
+      static let hitsController: HitsObservableController<PreviewRecord<String>> = .init()
+
+      static let interactor = HitsInteractor<PreviewRecord<String>>(infiniteScrolling: .off, showItemsOnEmptyQuery: true)
+
       static var previews: some View {
-        let hitsController: HitsObservableController<String> = .init()
         NavigationView {
           HitsList(hitsController) { string, _ in
             VStack {
               HStack {
-                Text(string ?? "---")
+                Text(string?.value ?? "---")
                   .frame(maxWidth: .infinity, minHeight: 30, maxHeight: .infinity, alignment: .leading)
                   .padding(.horizontal, 16)
               }
@@ -88,20 +121,30 @@
           }
           .padding(.top, 20)
           .onAppear {
-            hitsController.hits = ["One", "Two", "Three"]
-          }.navigationBarTitle("Hits")
+            hitsController.hitsSource = interactor
+
+            let results = try! JSONDecoder().decode(SearchResponse.self, from: rawHits)
+
+            interactor.onResultsUpdated.subscribe(with: hitsController) { (reb, hit) in
+              reb.reload()
+            }
+            interactor.update(results)
+          }
+          .navigationBarTitle("Hits")
         }
+
         NavigationView {
           HitsList(hitsController) { string, _ in
             VStack {
               HStack {
-                Text(string ?? "---")
+                Text(string?.value ?? "---")
               }
               Divider()
             }
           } noResults: {
             Text("No results")
-          }.navigationBarTitle("Hits")
+          }
+          .navigationBarTitle("Hits")
         }
       }
     }

Tests/InstantSearchCoreTests/Unit/Hits/HitsInteractorTests.swift

@@ -220,7 +220,35 @@ class HitsInteractorTests: XCTestCase {
       XCTAssertEqual(hitsInteractor.hit(atIndex: 1), Person(firstName: "Helen", lastName: "Smith"))
       exp.fulfill()
     }
-
+    
     waitForExpectations(timeout: 5)
+
   }
+
+  func testClearTriggering() throws {
+    let paginationController = Paginator<TestRecord<Int>>()
+    let infiniteScrollingController = TestInfiniteScrollingController()
+
+    let hits = (0..<20).map(TestRecord.withValue)
+    let results = SearchResponse(hits: hits)
+
+    let vm = HitsInteractor(
+      settings: .init(showItemsOnEmptyQuery: true),
+      paginationController: paginationController,
+      infiniteScrollingController: infiniteScrollingController
+    )
+
+    let exp = expectation(description: "on results updated")
+
+    vm.onResultsUpdated.subscribe(with: self) { (_, _) in
+      XCTAssertEqual(vm.numberOfHits(), hits.count)
+      exp.fulfill()
+    }
+    vm.update(results)
+    waitForExpectations(timeout: 3, handler: .none)
+
+    vm.clear()
+    XCTAssertEqual(vm.numberOfHits(), 0)
+  }
+
 }

Tests/InstantSearchCoreTests/Unit/MultiIndexHitsInteractorTests.swift

@@ -356,5 +356,9 @@ class MultiIndexHitsInteractorTests: XCTestCase {
     func loadMoreResults() {
       didCallLoadMoreResults()
     }
+
+    func clear() {
+
+    }
   }
 }

Tests/InstantSearchCoreTests/Unit/PaginatorTests.swift

@@ -86,4 +86,15 @@ class PaginatorTests: XCTestCase {
     XCTAssertNotNil(paginator.pageMap)
     XCTAssertEqual(paginator.pageMap?.count, 3)
   }
+
+  func testClear() {
+    let paginator = Paginator<String>()
+    let page = TestPageable(index: 0, items: ["i1", "i2", "i3"])
+    paginator.process(page)
+    XCTAssertEqual(paginator.pageMap?.count, 3)
+
+    paginator.clear()
+    XCTAssertNil(paginator.pageMap)
+  }
+
 }