Implement didHighlight and didUnhighlight APIs (#123)

nuomi1 · jessesquires · web-flow · commit 46e19c58276f · 2024-08-13T10:56:49.000-07:00
Closes #95 --------- Co-authored-by: Jesse Squires <jesse@jessesquires.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,11 @@ NEXT
 
 - TBA
 
+0.1.5
+-----
+
+- Implemented `didHighlight()` and `didUnhighlight()` APIs for `CellViewModel`. ([@nuomi1](https://github.com/nuomi1), [#123](https://github.com/jessesquires/ReactiveCollectionsKit/pull/123))
+
 0.1.4
 -----
 
diff --git a/Sources/CellViewModel.swift b/Sources/CellViewModel.swift
@@ -44,6 +44,14 @@ public protocol CellViewModel: DiffableViewModel, ViewRegistrationProvider {
     /// Tells the view model that its cell was removed from the collection view.
     /// This corresponds to the delegate method `collectionView(_:didEndDisplaying:forItemAt:)`.
     func didEndDisplaying()
+
+    /// Tells the view model that its cell was highlighted.
+    /// This corresponds to the delegate method `collectionView(_:didHighlightItemAt:)`.
+    func didHighlight()
+
+    /// Tells the view model that the highlight was removed from its cell.
+    /// This corresponds to the delegate method `collectionView(_:didUnhighlightItemAt:)`.
+    func didUnhighlight()
 }
 
 extension CellViewModel {
@@ -65,6 +73,12 @@ extension CellViewModel {
 
     /// Default implementation. Does nothing.
     public func didEndDisplaying() { }
+
+    /// Default implementation. Does nothing.
+    public func didHighlight() { }
+
+    /// Default implementation. Does nothing.
+    public func didUnhighlight() { }
 }
 
 extension CellViewModel {
@@ -148,6 +162,16 @@ public struct AnyCellViewModel: CellViewModel {
         self._didEndDisplaying()
     }
 
+    /// :nodoc:
+    public func didHighlight() {
+        self._didHighlight()
+    }
+
+    /// :nodoc:
+    public func didUnhighlight() {
+        self._didUnhighlight()
+    }
+
     /// :nodoc: "override" the extension
     public let cellClass: AnyClass
 
@@ -165,6 +189,8 @@ public struct AnyCellViewModel: CellViewModel {
     private let _didSelect: (CellEventCoordinator?) -> Void
     private let _willDisplay: () -> Void
     private let _didEndDisplaying: () -> Void
+    private let _didHighlight: () -> Void
+    private let _didUnhighlight: () -> Void
 
     // MARK: Init
 
@@ -190,6 +216,8 @@ public struct AnyCellViewModel: CellViewModel {
         }
         self._willDisplay = viewModel.willDisplay
         self._didEndDisplaying = viewModel.didEndDisplaying
+        self._didHighlight = viewModel.didHighlight
+        self._didUnhighlight = viewModel.didUnhighlight
         self.cellClass = viewModel.cellClass
         self.reuseIdentifier = viewModel.reuseIdentifier
     }
diff --git a/Sources/CollectionViewDriver.swift b/Sources/CollectionViewDriver.swift
@@ -302,6 +302,18 @@ extension CollectionViewDriver: UICollectionViewDelegate {
         self.viewModel.cellViewModel(at: indexPath).shouldHighlight
     }
 
+    /// :nodoc:
+    public func collectionView(_ collectionView: UICollectionView,
+                               didHighlightItemAt indexPath: IndexPath) {
+        self.viewModel.cellViewModel(at: indexPath).didHighlight()
+    }
+
+    /// :nodoc:
+    public func collectionView(_ collectionView: UICollectionView,
+                               didUnhighlightItemAt indexPath: IndexPath) {
+        self.viewModel.cellViewModel(at: indexPath).didUnhighlight()
+    }
+
     // MARK: Managing context menus
 
     /// :nodoc:
diff --git a/Tests/Fakes/FakeCellNibView.swift b/Tests/Fakes/FakeCellNibView.swift
@@ -54,6 +54,16 @@ struct FakeCellNibViewModel: CellViewModel {
         self.expectationDidEndDisplaying?.fulfillAndLog()
     }
 
+    var expectationDidHighlight: XCTestExpectation?
+    func didHighlight() {
+        self.expectationDidHighlight?.fulfillAndLog()
+    }
+
+    var expectationDidUnhighlight: XCTestExpectation?
+    func didUnhighlight() {
+        self.expectationDidUnhighlight?.fulfillAndLog()
+    }
+
     nonisolated static func == (left: Self, right: Self) -> Bool {
         left.id == right.id
     }
diff --git a/Tests/Fakes/FakeCollectionViewModel.swift b/Tests/Fakes/FakeCollectionViewModel.swift
@@ -34,7 +34,9 @@ extension XCTestCase {
         expectDidSelectCell: Bool = false,
         expectConfigureCell: Bool = false,
         expectWillDisplay: Bool = false,
-        expectDidEndDisplaying: Bool = false
+        expectDidEndDisplaying: Bool = false,
+        expectDidHighlight: Bool = false,
+        expectDidUnhighlight: Bool = false
     ) -> CollectionViewModel {
         let sections = (0..<numSections).map { sectionIndex in
             self.fakeSectionViewModel(
@@ -50,7 +52,9 @@ extension XCTestCase {
                 expectDidSelectCell: expectDidSelectCell,
                 expectConfigureCell: expectConfigureCell,
                 expectWillDisplay: expectWillDisplay,
-                expectDidEndDisplaying: expectDidEndDisplaying
+                expectDidEndDisplaying: expectDidEndDisplaying,
+                expectDidHighlight: expectDidHighlight,
+                expectDidUnhighlight: expectDidUnhighlight
             )
         }
         return CollectionViewModel(id: "collection_\(id)", sections: sections)
@@ -70,7 +74,9 @@ extension XCTestCase {
         expectDidSelectCell: Bool = false,
         expectConfigureCell: Bool = false,
         expectWillDisplay: Bool = false,
-        expectDidEndDisplaying: Bool = false
+        expectDidEndDisplaying: Bool = false,
+        expectDidHighlight: Bool = false,
+        expectDidUnhighlight: Bool = false
     ) -> SectionViewModel {
         let cells = self.fakeCellViewModels(
             id: cellId,
@@ -80,7 +86,9 @@ extension XCTestCase {
             expectDidSelectCell: expectDidSelectCell,
             expectConfigureCell: expectConfigureCell,
             expectWillDisplay: expectWillDisplay,
-            expectDidEndDisplaying: expectDidEndDisplaying
+            expectDidEndDisplaying: expectDidEndDisplaying,
+            expectDidHighlight: expectDidHighlight,
+            expectDidUnhighlight: expectDidUnhighlight
         )
         var header = includeHeader ? FakeHeaderViewModel() : nil
         header?.expectationWillDisplay = self._willDisplayExpectation(expect: expectWillDisplay, id: "Header")
@@ -114,7 +122,9 @@ extension XCTestCase {
         expectDidSelectCell: Bool = false,
         expectConfigureCell: Bool = false,
         expectWillDisplay: Bool = false,
-        expectDidEndDisplaying: Bool = false
+        expectDidEndDisplaying: Bool = false,
+        expectDidHighlight: Bool = false,
+        expectDidUnhighlight: Bool = false
     ) -> [AnyCellViewModel] {
         var cells = [AnyCellViewModel]()
         for cellIndex in 0..<count {
@@ -125,7 +135,9 @@ extension XCTestCase {
                 expectDidSelectCell: expectDidSelectCell,
                 expectConfigureCell: expectConfigureCell,
                 expectWillDisplay: expectWillDisplay,
-                expectDidEndDisplaying: expectDidEndDisplaying
+                expectDidEndDisplaying: expectDidEndDisplaying,
+                expectDidHighlight: expectDidHighlight,
+                expectDidUnhighlight: expectDidUnhighlight
             )
             cells.append(model)
         }
@@ -140,14 +152,18 @@ extension XCTestCase {
         expectDidSelectCell: Bool,
         expectConfigureCell: Bool,
         expectWillDisplay: Bool,
-        expectDidEndDisplaying: Bool
+        expectDidEndDisplaying: Bool,
+        expectDidHighlight: Bool,
+        expectDidUnhighlight: Bool
     ) -> AnyCellViewModel {
         if useNibs {
             var viewModel = FakeCellNibViewModel(id: id)
             viewModel.expectationDidSelect = self._cellDidSelectExpectation(expect: expectDidSelectCell, id: viewModel.id)
             viewModel.expectationConfigureCell = self._cellConfigureExpectation(expect: expectConfigureCell, id: viewModel.id)
             viewModel.expectationWillDisplay = self._willDisplayExpectation(expect: expectWillDisplay, id: viewModel.id)
             viewModel.expectationDidEndDisplaying = self._didEndDisplayingExpectation(expect: expectDidEndDisplaying, id: viewModel.id)
+            viewModel.expectationDidHighlight = self._didHighlightExpectation(expect: expectDidHighlight, id: viewModel.id)
+            viewModel.expectationDidUnhighlight = self._didUnhighlightExpectation(expect: expectDidUnhighlight, id: viewModel.id)
             return viewModel.eraseToAnyViewModel()
         }
 
@@ -157,6 +173,8 @@ extension XCTestCase {
             viewModel.expectationConfigureCell = self._cellConfigureExpectation(expect: expectConfigureCell, id: viewModel.id)
             viewModel.expectationWillDisplay = self._willDisplayExpectation(expect: expectWillDisplay, id: viewModel.id)
             viewModel.expectationDidEndDisplaying = self._didEndDisplayingExpectation(expect: expectDidEndDisplaying, id: viewModel.id)
+            viewModel.expectationDidHighlight = self._didHighlightExpectation(expect: expectDidHighlight, id: viewModel.id)
+            viewModel.expectationDidUnhighlight = self._didUnhighlightExpectation(expect: expectDidUnhighlight, id: viewModel.id)
             return viewModel.eraseToAnyViewModel()
         }
 
@@ -165,6 +183,8 @@ extension XCTestCase {
         viewModel.expectationConfigureCell = self._cellConfigureExpectation(expect: expectConfigureCell, id: viewModel.id)
         viewModel.expectationWillDisplay = self._willDisplayExpectation(expect: expectWillDisplay, id: viewModel.id)
         viewModel.expectationDidEndDisplaying = self._didEndDisplayingExpectation(expect: expectDidEndDisplaying, id: viewModel.id)
+        viewModel.expectationDidHighlight = self._didHighlightExpectation(expect: expectDidHighlight, id: viewModel.id)
+        viewModel.expectationDidUnhighlight = self._didUnhighlightExpectation(expect: expectDidUnhighlight, id: viewModel.id)
         return viewModel.eraseToAnyViewModel()
     }
 
@@ -187,6 +207,16 @@ extension XCTestCase {
     private func _didEndDisplayingExpectation(expect: Bool, id: UniqueIdentifier) -> XCTestExpectation? {
         expect ? self.expectation(description: "didEndDisplaying_\(id)") : nil
     }
+
+    @MainActor
+    private func _didHighlightExpectation(expect: Bool, id: UniqueIdentifier) -> XCTestExpectation? {
+        expect ? self.expectation(description: "didHighlight_\(id)") : nil
+    }
+
+    @MainActor
+    private func _didUnhighlightExpectation(expect: Bool, id: UniqueIdentifier) -> XCTestExpectation? {
+        expect ? self.expectation(description: "didUnhighlight_\(id)") : nil
+    }
 }
 
 // swiftlint:enable function_parameter_count
diff --git a/Tests/Fakes/FakeNumberModel.swift b/Tests/Fakes/FakeNumberModel.swift
@@ -56,6 +56,16 @@ struct FakeNumberCellViewModel: CellViewModel {
         self.expectationDidEndDisplaying?.fulfillAndLog()
     }
 
+    var expectationDidHighlight: XCTestExpectation?
+    func didHighlight() {
+        self.expectationDidHighlight?.fulfillAndLog()
+    }
+
+    var expectationDidUnhighlight: XCTestExpectation?
+    func didUnhighlight() {
+        self.expectationDidUnhighlight?.fulfillAndLog()
+    }
+
     init(model: FakeNumberModel = FakeNumberModel()) {
         self.model = model
     }
diff --git a/Tests/Fakes/FakeTextModel.swift b/Tests/Fakes/FakeTextModel.swift
@@ -55,6 +55,16 @@ struct FakeTextCellViewModel: CellViewModel {
         self.expectationDidEndDisplaying?.fulfillAndLog()
     }
 
+    var expectationDidHighlight: XCTestExpectation?
+    func didHighlight() {
+        self.expectationDidHighlight?.fulfillAndLog()
+    }
+
+    var expectationDidUnhighlight: XCTestExpectation?
+    func didUnhighlight() {
+        self.expectationDidUnhighlight?.fulfillAndLog()
+    }
+
     init(
         model: FakeTextModel = FakeTextModel(),
         shouldHighlight: Bool = true,
diff --git a/Tests/TestCellViewModel.swift b/Tests/TestCellViewModel.swift
@@ -55,6 +55,12 @@ final class TestCellViewModel: XCTestCase {
         viewModel.expectationDidEndDisplaying = self.expectation(name: "did_end_displaying")
         viewModel.expectationDidEndDisplaying?.expectedFulfillmentCount = 2
 
+        viewModel.expectationDidHighlight = self.expectation(name: "did_highlight")
+        viewModel.expectationDidHighlight?.expectedFulfillmentCount = 2
+
+        viewModel.expectationDidUnhighlight = self.expectation(name: "did_unhighlight")
+        viewModel.expectationDidUnhighlight?.expectedFulfillmentCount = 2
+
         let erased = viewModel.eraseToAnyViewModel()
         XCTAssertEqual(viewModel.hashValue, erased.hashValue)
 
@@ -69,11 +75,15 @@ final class TestCellViewModel: XCTestCase {
         viewModel.didSelect(with: nil)
         viewModel.willDisplay()
         viewModel.didEndDisplaying()
+        viewModel.didHighlight()
+        viewModel.didUnhighlight()
 
         erased.configure(cell: FakeTextCollectionCell())
         erased.didSelect(with: nil)
         erased.willDisplay()
         erased.didEndDisplaying()
+        erased.didHighlight()
+        erased.didUnhighlight()
 
         self.waitForExpectations()
 
diff --git a/Tests/TestCollectionViewDriver.swift b/Tests/TestCollectionViewDriver.swift
@@ -199,6 +199,35 @@ final class TestCollectionViewDriver: UnitTestCase {
         self.keepDriverAlive(driver)
     }
 
+    @MainActor
+    func test_delegate_didHighlight_didUnhighlight_calls_cellViewModel() {
+        let sections = 2
+        let cells = 5
+        let model = self.fakeCollectionViewModel(
+            numSections: sections,
+            numCells: cells,
+            expectDidHighlight: true,
+            expectDidUnhighlight: true
+        )
+        let driver = CollectionViewDriver(
+            view: self.collectionView,
+            viewModel: model,
+            options: .test()
+        )
+
+        for section in 0..<sections {
+            for item in 0..<cells {
+                let indexPath = IndexPath(item: item, section: section)
+                driver.collectionView(self.collectionView, didHighlightItemAt: indexPath)
+                driver.collectionView(self.collectionView, didUnhighlightItemAt: indexPath)
+            }
+        }
+
+        self.waitForExpectations()
+
+        self.keepDriverAlive(driver)
+    }
+
     @MainActor
     func test_dataSource_cellForItemAt_calls_cellViewModel_configure() async {
         let viewController = FakeCollectionViewController()

-Original file line number
+Diff line change
 - TBA
 +0.1.5
 +-----
++
 +- Implemented `didHighlight()` and `didUnhighlight()` APIs for `CellViewModel`. ([@nuomi1](https://github.com/nuomi1), [#123](https://github.com/jessesquires/ReactiveCollectionsKit/pull/123))
++
 .1.4
 -----