Merge pull request #10 from daangn/feature/david/tracking-delegate-im…

…provement willBeginTracking and didTrack redefinition
daangn · Oct 28, 2022 · bca0d56 · bca0d56
2 parents de0f3e7 + 97cf427
commit bca0d56
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Showing 9 changed files with 111 additions and 26 deletions.
diff --git a/Example/SushiBelt/ViewController.swift b/Example/SushiBelt/ViewController.swift
@@ -179,6 +179,11 @@ extension ViewController: SushiBeltTrackerDelegate {
 
     print("🚀 begin tracking: \(item.debugDescription)")
   }
+
+  func didTrack(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem) {
+
+    print("🎯 tracked: \(item.debugDescription)")
+  }
 
   func didEndTracking(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem) {
 

diff --git a/Sources/SushiBelt/Private/SushiBeltTrackerItemDiffChecker.swift b/Sources/SushiBelt/Private/SushiBeltTrackerItemDiffChecker.swift
@@ -24,9 +24,11 @@ public final class DefaultSushiBeltTrackerItemDiffChecker: SushiBeltTrackerItemD
     )
 
     let endedItems = updatedItems.subtracting(newItems)
+    let newItems = updatedItems.subtracting(oldItems)
 
     return SushiBeltTrackerItemDiffResult(
       calculationTargetedItems: updatedItems.subtracting(endedItems),
+      newItems: newItems,
       endedItems: endedItems
     )
   }

diff --git a/Sources/SushiBelt/Private/SushiBeltTrackerItemDiffResult.swift b/Sources/SushiBelt/Private/SushiBeltTrackerItemDiffResult.swift
@@ -9,13 +9,16 @@ import Foundation
 
 public struct SushiBeltTrackerItemDiffResult {
   public let calculationTargetedItems: Set<SushiBeltTrackerItem>
+  public let newItems: Set<SushiBeltTrackerItem>
   public let endedItems: Set<SushiBeltTrackerItem>
 
   public init(
     calculationTargetedItems: Set<SushiBeltTrackerItem>,
+    newItems: Set<SushiBeltTrackerItem>,
     endedItems: Set<SushiBeltTrackerItem>
   ) {
     self.calculationTargetedItems = calculationTargetedItems
+    self.newItems = newItems
     self.endedItems = endedItems
   }
 }
diff --git a/Sources/SushiBelt/SushiBeltTracker.swift b/Sources/SushiBelt/SushiBeltTracker.swift
@@ -48,7 +48,7 @@ public final class SushiBeltTracker {
     )
 
     self.cachedItems = result.calculationTargetedItems
-
+    self.willBeginTracking(items: result.newItems)
     self.checkBeginTrackingItems(items: self.cachedItems)
     self.didEndTracking(items: result.endedItems)
 
@@ -97,7 +97,7 @@ extension SushiBeltTracker {
       /// delegate willBeginTracking
       if shouldSendWillBeginTracking {
         mutableItem.isTracked = true
-        self.delegate?.willBeginTracking(self, item: mutableItem)
+        self.delegate?.didTrack(self, item: mutableItem)
       }
 
       /// update cached item
@@ -139,7 +139,13 @@ extension SushiBeltTracker {
       scrollDirection: self.recentScrollDirection
     )
   }
-
+
+  private func willBeginTracking(items: Set<SushiBeltTrackerItem>) {
+    items.forEach {
+      self.delegate?.willBeginTracking(self, item: $0)
+    }
+  }
+
   private func didEndTracking(items: Set<SushiBeltTrackerItem>) {
     items.forEach {
       self.delegate?.didEndTracking(self, item: $0)

diff --git a/Sources/SushiBelt/SushiBeltTrackerDelegate.swift b/Sources/SushiBelt/SushiBeltTrackerDelegate.swift
@@ -10,5 +10,6 @@ import UIKit
 
 public protocol SushiBeltTrackerDelegate: AnyObject {
   func willBeginTracking(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem)
+  func didTrack(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem)
   func didEndTracking(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem)
 }
diff --git a/Tests/SushiBeltTests/Private/SushiBeltTrackerItemDiffCheckerTests.swift b/Tests/SushiBeltTests/Private/SushiBeltTrackerItemDiffCheckerTests.swift
@@ -64,7 +64,7 @@ extension SushiBeltTrackerItemDiffCheckerTests {
   }
 }
 
-// MARK: - diff calculationTargeted & ended items
+// MARK: - diff calculationTargeted & new/ended items
 
 extension SushiBeltTrackerItemDiffCheckerTests {
 
@@ -84,7 +84,10 @@ extension SushiBeltTrackerItemDiffCheckerTests {
 
     // then
     XCTAssertEqual(result.calculationTargetedItems.count, 1)
-
+
+    XCTAssertEqual(result.newItems.count, 1)
+    XCTAssertEqual(result.newItems.first?.id, .index(1))
+
     XCTAssertEqual(result.endedItems.count, 0)
   }
 
@@ -111,9 +114,12 @@ extension SushiBeltTrackerItemDiffCheckerTests {
     // then
     XCTAssertEqual(result.calculationTargetedItems.count, 1)
     XCTAssertEqual(result.calculationTargetedItems.first, newItems.first)
-
+
+    XCTAssertEqual(result.newItems.count, 1)
+    XCTAssertEqual(result.newItems.first?.id, .index(200))
+
     XCTAssertEqual(result.endedItems.count, 1)
-    XCTAssertEqual(result.endedItems.first, oldItems.first)
+    XCTAssertEqual(result.endedItems.first?.id, .index(1))
   }
 
   func test_diff_overlaped_items_should_return_as_calculationTargetedItems() {
@@ -146,7 +152,10 @@ extension SushiBeltTrackerItemDiffCheckerTests {
       guard case let .index(index) = item.id else { return false }
       return index == 1
     }))
-
+
+    XCTAssertEqual(result.newItems.count, 1)
+    XCTAssertEqual(result.newItems.first?.id, .index(200))
+
     XCTAssertEqual(result.endedItems.count, 0)
   }
 
@@ -181,11 +190,11 @@ extension SushiBeltTrackerItemDiffCheckerTests {
     // then
     XCTAssertEqual(result.calculationTargetedItems.count, 2)
     XCTAssertEqual(result.calculationTargetedItems, newItems)
-
+
+    XCTAssertEqual(result.newItems.count, 1)
+    XCTAssertEqual(result.newItems.first?.id, .index(200))
+
     XCTAssertEqual(result.endedItems.count, 1)
-    XCTAssertTrue(result.endedItems.contains(where: { item in
-      guard case let .index(index) = item.id else { return false }
-      return index == 1
-    }))
+    XCTAssertEqual(result.endedItems.first?.id, .index(1))
   }
 }
diff --git a/Tests/SushiBeltTests/SushiBeltTrackerTests.swift b/Tests/SushiBeltTests/SushiBeltTrackerTests.swift
@@ -180,7 +180,7 @@ extension SushiBeltTrackerTests {
   }
 }
 
-// MARK: - checkBeginTrackingItems
+// MARK: - tracked
 
 extension SushiBeltTrackerTests {
 
@@ -221,7 +221,7 @@ extension SushiBeltTrackerTests {
     XCTAssertEqual(trackedItems.count, 1)
   }
 
-  func test_checkBeginTrackingItems_should_call_willBeginTracking() {
+  func test_checkBeginTrackingItems_should_call_didTrack() {
     // given
     let tracker = self.createTracker()
     let items = [
@@ -256,13 +256,14 @@ extension SushiBeltTrackerTests {
     // then
     let trackedItems = tracker.cachedItems.filter({ $0.isTracked })
     XCTAssertEqual(trackedItems.count, 1)
-    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItem?.currentVisibleRatio, 0.8)
-    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItem?.objectiveVisibleRatio, 0.5)
-    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItem?.isTracked, true)
-    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItem?.id, .index(2))
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.count, 1)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.first?.currentVisibleRatio, 0.8)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.first?.objectiveVisibleRatio, 0.5)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.first?.isTracked, true)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.first?.id, .index(2))
   }
 
-  func test_checkBeginTrackingItems_should_not_call_willBeginTracking_on_already_tracked() {
+  func test_checkBeginTrackingItems_should_not_call_didTrack_on_already_tracked() {
     // given
     let tracker = self.createTracker()
     let items = [
@@ -297,6 +298,57 @@ extension SushiBeltTrackerTests {
     // then
     let trackedItems = tracker.cachedItems.filter({ $0.isTracked })
     XCTAssertEqual(trackedItems.count, 1)
-    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItem, nil)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didTrackItems.isEmpty, true)
+  }
+}
+
+// MARK: - willBeginTracking
+
+extension SushiBeltTrackerTests {
+
+  func test_checkBeginTrackingItems_willBeginTracking() {
+    // given
+    let tracker = self.createTracker()
+    let items = [
+      SushiBeltTrackerItem(
+        id: .index(1),
+        view: UIView(frame: .zero)
+      ).frameInWindow(CGRect(x: 0.0, y: 100.0, width: 100.0, height: 100.0))
+    ]
+
+    tracker.cachedItems = .init()
+
+    // when
+    tracker.calculateItemsIfNeeded(items: items)
+
+    // then
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItems.count, 1)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didEndTrackingItems.count, 0)
+  }
+}
+
+
+// MARK: - didEndTracking
+
+extension SushiBeltTrackerTests {
+
+  func test_checkBeginTrackingItems_didEndTracking() {
+    // given
+    let tracker = self.createTracker()
+    let items: [SushiBeltTrackerItem] = []
+
+    tracker.cachedItems = .init([
+      SushiBeltTrackerItem(
+        id: .index(1),
+        view: UIView(frame: .zero)
+      ).frameInWindow(CGRect(x: 0.0, y: 100.0, width: 100.0, height: 100.0))
+    ])
+
+    // when
+    tracker.calculateItemsIfNeeded(items: items)
+
+    // then
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.willBeginTrackingItems.count, 0)
+    XCTAssertEqual(self.sushiBeltTrackerDelegate.didEndTrackingItems.count, 1)
   }
 }
diff --git a/Tests/SushiBeltTests/TestDoubles/SushiBeltTrackerDelegateSpy.swift b/Tests/SushiBeltTests/TestDoubles/SushiBeltTrackerDelegateSpy.swift
@@ -10,16 +10,22 @@ import Foundation
 
 final class SushiBeltTrackerDelegateSpy: SushiBeltTrackerDelegate {
 
-  var willBeginTrackingItem: SushiBeltTrackerItem?
+  var willBeginTrackingItems: [SushiBeltTrackerItem] = []
 
   func willBeginTracking(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem) {
-    self.willBeginTrackingItem = item
+    self.willBeginTrackingItems.append(item)
   }
-
-  var didEndTrackingItem: SushiBeltTrackerItem?
+
+  var didTrackItems: [SushiBeltTrackerItem] = []
+
+  func didTrack(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem) {
+    self.didTrackItems.append(item)
+  }
+
+  var didEndTrackingItems: [SushiBeltTrackerItem] = []
 
   func didEndTracking(_ tracker: SushiBeltTracker, item: SushiBeltTrackerItem) {
-    self.didEndTrackingItem = item
+    self.didEndTrackingItems.append(item)
   }
 
 }
diff --git a/Tests/SushiBeltTests/TestDoubles/SushiBeltTrackerItemDiffCheckerSpy.swift b/Tests/SushiBeltTests/TestDoubles/SushiBeltTrackerItemDiffCheckerSpy.swift
@@ -15,6 +15,7 @@ final class SushiBeltTrackerItemDiffCheckerSpy: SushiBeltTrackerItemDiffChecker
   var diffNewItems: Set<SushiBeltTrackerItem>?
   var diffStub: SushiBeltTrackerItemDiffResult = .init(
     calculationTargetedItems: .init(),
+    newItems: .init(),
     endedItems: .init()
   )