add deleteAtIndex method (#101)

mac-gallagher · Jul 12, 2020 · 9a21773 · 9a21773
1 parent 58cbf76
commit 9a21773
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diff --git a/Shuffle-iOS.podspec b/Shuffle-iOS.podspec
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
 s.name         = "Shuffle-iOS"
-s.version      = "0.3.1"
+s.version      = "0.3.2"
 s.platform     = :ios, "9.0"
 s.summary      = "A multi-directional card swiping library inspired by Tinder"
 
@@ -13,7 +13,7 @@ s.homepage     = "https://github.com/mac-gallagher/Shuffle"
 s.documentation_url = "https://github.com/mac-gallagher/Shuffle/tree/master/README.md"
 s.license      = { :type => 'MIT', :file => 'LICENSE' }
 s.author       = { "Mac Gallagher" => "[email protected]" }
-s.source       = { :git => "https://github.com/mac-gallagher/Shuffle.git", :tag => "v0.3.1" }
+s.source       = { :git => "https://github.com/mac-gallagher/Shuffle.git", :tag => "v0.3.2" }
 
 s.swift_version = "5.0"
 s.source_files = "Sources/**/*.{h,swift}"

diff --git a/Shuffle.xcodeproj/project.pbxproj b/Shuffle.xcodeproj/project.pbxproj
@@ -91,6 +91,7 @@
 		ADEE86E822ADF3C200AAE7A1 /* CardStackLayoutProviderSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = ADEE86E722ADF3C200AAE7A1 /* CardStackLayoutProviderSpec.swift */; };
 		ADFAAC0A23FA66540084323B /* CardStackStateManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = ADFAAC0923FA66540084323B /* CardStackStateManager.swift */; };
 		ADFAAC0C23FB75D30084323B /* MockCardStackStateManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = ADFAAC0B23FB75D30084323B /* MockCardStackStateManager.swift */; };
+		ADFDBA0524B9B94C0069E256 /* SwipeCardStackSpec_StateManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = ADFDBA0424B9B94C0069E256 /* SwipeCardStackSpec_StateManager.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -203,6 +204,7 @@
 		ADEE86E722ADF3C200AAE7A1 /* CardStackLayoutProviderSpec.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CardStackLayoutProviderSpec.swift; sourceTree = "<group>"; };
 		ADFAAC0923FA66540084323B /* CardStackStateManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CardStackStateManager.swift; sourceTree = "<group>"; };
 		ADFAAC0B23FB75D30084323B /* MockCardStackStateManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MockCardStackStateManager.swift; sourceTree = "<group>"; };
+		ADFDBA0424B9B94C0069E256 /* SwipeCardStackSpec_StateManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SwipeCardStackSpec_StateManager.swift; sourceTree = "<group>"; };
 		CF2ADEA1F05DDE3996336C1F /* Pods-ShuffleExample.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-ShuffleExample.release.xcconfig"; path = "Target Support Files/Pods-ShuffleExample/Pods-ShuffleExample.release.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -507,6 +509,7 @@
 				AD4170A724034D4200BD40C8 /* CardStackStateManagerSpec.swift */,
 				ADEE86DE22ADED3600AAE7A1 /* SwipeCardStackSpec_Base.swift */,
 				AD9F44BB2468D04600725A8D /* SwipeCardStackSpec_MainMethods.swift */,
+				ADFDBA0424B9B94C0069E256 /* SwipeCardStackSpec_StateManager.swift */,
 				AD9F44BD2468D08B00725A8D /* SwipeCardStackSpec_SwipeCardDelegate.swift */,
 			);
 			path = Specs;
@@ -796,6 +799,7 @@
 				AD439DF92285FB7E009DE2F7 /* TestableSwipeView.swift in Sources */,
 				AD4170A824034D4200BD40C8 /* CardStackStateManagerSpec.swift in Sources */,
 				ADC3622D2466B23E00FB9F1C /* SwipeCardSpec_Base.swift in Sources */,
+				ADFDBA0524B9B94C0069E256 /* SwipeCardStackSpec_StateManager.swift in Sources */,
 				AD9F44BC2468D04600725A8D /* SwipeCardStackSpec_MainMethods.swift in Sources */,
 				AD52EF8B22E532B90063AE5D /* TestableNotificationCenter.swift in Sources */,
 				AD1098382287CAD4008CB197 /* TestableSwipeCard.swift in Sources */,

diff --git a/Sources/Shuffle/SwipeCardStack/CardStackStateManager.swift b/Sources/Shuffle/SwipeCardStack/CardStackStateManager.swift
@@ -32,6 +32,7 @@ protocol CardStackStateManagable {
   var totalIndexCount: Int { get }
 
   func insert(_ index: Int, at position: Int)
+  func delete(_ index: Int)
 
   func swipe(_ direction: SwipeDirection)
   func undoSwipe() -> Swipe?
@@ -57,29 +58,34 @@ class CardStackStateManager: CardStackStateManagable {
   }
 
   func insert(_ index: Int, at position: Int) {
-    if position < 0 {
-      fatalError("Attempt to insert card at position \(position)")
-    }
+    precondition(index >= 0, "Attempt to insert card at index \(index)")
+    //swiftlint:disable:next line_length
+    precondition(index <= totalIndexCount, "Attempt to insert card at index \(index), but there are only \(totalIndexCount + 1) cards after the update")
+    precondition(position >= 0, "Attempt to insert card at position \(position)")
+    //swiftlint:disable:next line_length
+    precondition(position <= remainingIndices.count, "Attempt to insert card at position \(position), but there are only \(remainingIndices.count + 1) cards remaining in the stack after the update")
+
+    // Increment all stored indices greater than or equal to index by 1
+    remainingIndices = remainingIndices.map { $0 >= index ? $0 + 1 : $0 }
+    swipes = swipes.map { $0.index >= index ? Swipe($0.index + 1, $0.direction) : $0 }
 
-    if position > remainingIndices.count {
-      //swiftlint:disable:next line_length
-      fatalError("Attempt to insert card at position \(position), but there are only \(remainingIndices.count + 1) cards remaining in the stack after the update")
-    }
+    remainingIndices.insert(index, at: position)
+  }
 
-    if index < 0 {
-      fatalError("Attempt to insert card at data source index \(index)")
-    }
+  func delete(_ index: Int) {
+    precondition(index >= 0, "Attempt to delete card at index \(index)")
+    //swiftlint:disable:next line_length
+    precondition(index < totalIndexCount, "Attempt to delete card at index \(index), but there are only \(totalIndexCount) cards before the update")
 
-    if index > totalIndexCount {
-      //swiftlint:disable:next line_length
-      fatalError("Attempt to insert card at index \(index), but there are only \(totalIndexCount + 1) cards after the update")
-    }
+    swipes.removeAll { return $0.index == index }
 
-    // Increment all stored indices in the range [0, index] by 1
-    remainingIndices = remainingIndices.map { $0 >= index ? $0 + 1 : $0 }
-    swipes = swipes.map { $0.index >= index ? Swipe($0.index + 1, $0.direction) : $0 }
+    if let position = remainingIndices.firstIndex(of: index) {
+      remainingIndices.remove(at: position)
+    }
 
-    remainingIndices.insert(index, at: position)
+    // Decrement all stored indices greater than or equal to index by 1
+    remainingIndices = remainingIndices.map { $0 >= index ? $0 - 1 : $0 }
+    swipes = swipes.map { $0.index >= index ? Swipe($0.index - 1, $0.direction) : $0 }
   }
 
   func swipe(_ direction: SwipeDirection) {

diff --git a/Sources/Shuffle/SwipeCardStack/SwipeCardStack.swift b/Sources/Shuffle/SwipeCardStack/SwipeCardStack.swift
@@ -83,7 +83,7 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
 
   private var animator: CardStackAnimatable = CardStackAnimator.shared
   private var layoutProvider: CardStackLayoutProvidable = CardStackLayoutProvider.shared
-  private var notificationCenter = NotificationCenter.default
+  private var notificationCenter = NotificationCenter()
   private var stateManager: CardStackStateManagable = CardStackStateManager()
   private var transformProvider: CardStackTransformProvidable = CardStackTransformProvider.shared
 
@@ -351,6 +351,26 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
     reloadVisibleCards()
   }
 
+  /// Deletes the card at the specified index. Removes swipes
+  /// - Parameter index: The index of the card in the data source
+  public func deleteCard(atIndex index: Int) {
+    guard let dataSource = dataSource else { return }
+
+    let oldNumberOfCards = stateManager.totalIndexCount
+    let newNumberOfCards = dataSource.numberOfCards(in: self)
+
+    stateManager.delete(index)
+
+    if newNumberOfCards != oldNumberOfCards - 1 {
+      let errorString = StringUtils.createInvalidUpdateErrorString(newCount: newNumberOfCards,
+                                                                   oldCount: oldNumberOfCards,
+                                                                   deletedCount: 1)
+      fatalError(errorString)
+    }
+
+    reloadVisibleCards()
+  }
+
   func reloadVisibleCards() {
     visibleCards.forEach { $0.card.removeFromSuperview() }
     visibleCards.removeAll()

diff --git a/Tests/ShuffleTests/SwipeCardStack/Mocks/MockCardStackStateManager.swift b/Tests/ShuffleTests/SwipeCardStack/Mocks/MockCardStackStateManager.swift
@@ -41,6 +41,14 @@ class MockCardStackStateManager: CardStackStateManagable {
     insertPositions.append(position)
   }
 
+  var deleteCalled: Bool = false
+  var deleteIndex: Int?
+
+  func delete(_ index: Int) {
+    deleteCalled = true
+    deleteIndex = index
+  }
+
   var swipeCalled = false
   var swipeDirection: SwipeDirection?
 

diff --git a/Tests/ShuffleTests/SwipeCardStack/Specs/CardStackStateManagerSpec.swift b/Tests/ShuffleTests/SwipeCardStack/Specs/CardStackStateManagerSpec.swift
@@ -61,7 +61,7 @@ class CardStackStateManagerSpec: QuickSpec {
         }
 
         it("should throw a fatal error") {
-          expect(subject.insert(4, at: position)).to(throwAssertion())
+          expect(subject.insert(0, at: position)).to(throwAssertion())
         }
       }
 
@@ -73,7 +73,7 @@ class CardStackStateManagerSpec: QuickSpec {
         }
 
         it("should throw a fatal error") {
-          expect(subject.insert(4, at: position)).to(throwAssertion())
+          expect(subject.insert(0, at: position)).to(throwAssertion())
         }
       }
 
@@ -118,7 +118,7 @@ class CardStackStateManagerSpec: QuickSpec {
           expect(subject.remainingIndices[position]) == index
         }
 
-        it("should increment all stored indices greater than index by one") {
+        it("should increment all stored indices greater than or equal to index by one") {
           expect(subject.remainingIndices[3]) == oldRemainingIndices[2] + 1
           expect(subject.remainingIndices[4]) == oldRemainingIndices[3] + 1
           expect(subject.swipes[1].index) == oldSwipes[1].index + 1
@@ -127,6 +127,81 @@ class CardStackStateManagerSpec: QuickSpec {
       }
     }
 
+    // MARK: - Delete
+
+    describe("When calling delete") {
+      context("and index is less than zero") {
+        let index: Int = -1
+
+        it("should throw a fatal error") {
+          expect(subject.delete(index)).to(throwAssertion())
+        }
+      }
+
+      context("and index is greater than the number of remaining indices - 1") {
+        let index: Int = 3
+
+        beforeEach {
+          subject.remainingIndices = [1, 2, 3]
+        }
+
+        it("should throw a fatal error") {
+          expect(subject.delete(index)).to(throwAssertion())
+        }
+      }
+
+      context("and index is at least zero and at most the number of remaining indices - 1") {
+        let oldRemainingIndices: [Int] = [3, 2, 5, 6, 0]
+        let oldSwipes = [Swipe(1, .left), Swipe(4, .left), Swipe(7, .left)]
+
+        beforeEach {
+          subject.remainingIndices = oldRemainingIndices
+          subject.swipes = oldSwipes
+        }
+
+        context("and the index has already been swiped") {
+          let index: Int = 4
+
+          beforeEach {
+            subject.delete(index)
+          }
+
+          it("should remove any swipes with the index") {
+            expect(subject.swipes.contains { $0.index == index }) == false
+            expect(subject.swipes.count) == oldSwipes.count - 1
+          }
+
+          it("should decrement all stored indices greater than or equal to index by one") {
+            expect(subject.remainingIndices[2]) == oldRemainingIndices[2] - 1
+            expect(subject.remainingIndices[3]) == oldRemainingIndices[3] - 1
+            expect(subject.swipes[1].index) == oldSwipes[2].index - 1
+          }
+        }
+
+        context("and the index has not been swiped") {
+          let index: Int = 2
+
+          beforeEach {
+            subject.delete(index)
+          }
+
+          it("should remove the index from remainingIndiecs") {
+            expect(subject.remainingIndices.count) == oldRemainingIndices.count - 1
+          }
+
+          it("should decrement all stored indices greater than or equal to index by one") {
+            expect(subject.remainingIndices[0]) == oldRemainingIndices[0] - 1
+            expect(subject.remainingIndices[1]) == oldRemainingIndices[2] - 1
+            expect(subject.remainingIndices[2]) == oldRemainingIndices[3] - 1
+            expect(subject.swipes[1].index) == oldSwipes[1].index - 1
+            expect(subject.swipes[2].index) == oldSwipes[2].index - 1
+          }
+        }
+      }
+    }
+
+      // MARK: - Delete At Position
+
     // MARK: - Swipe
 
     describe("When calling swipe") {