From 6006079dc8709a57df8c6f280955fc84d0a199c9 Mon Sep 17 00:00:00 2001
From: Soojin Ro <soojin.ro@momenti.tv>
Date: Sat, 11 Dec 2021 15:58:19 -0500
Subject: [PATCH] Fix FingerUp causing UITouch to end in start location (#35)

---
 .../EventGenerator+Hand.swift                 |  1 +
 Sources/Hammer/Utilties/TouchStorage.swift    |  6 +++++
 Tests/HammerTests/DragTests.swift             | 24 +++++++++++++++++++
 .../HammerTests/Utilities/TouchTestView.swift | 13 ++++++++++
 4 files changed, 44 insertions(+)
 create mode 100644 Tests/HammerTests/DragTests.swift
 create mode 100644 Tests/HammerTests/Utilities/TouchTestView.swift

diff --git a/Sources/Hammer/EventGenerator/EventGenerator+Hand/EventGenerator+Hand.swift b/Sources/Hammer/EventGenerator/EventGenerator+Hand/EventGenerator+Hand.swift
index beac887..a184d0d 100644
--- a/Sources/Hammer/EventGenerator/EventGenerator+Hand/EventGenerator+Hand.swift
+++ b/Sources/Hammer/EventGenerator/EventGenerator+Hand/EventGenerator+Hand.swift
@@ -498,6 +498,7 @@ extension EventGenerator {
                 throw HammerError.touchForFingerDoesNotExist(index: finger.fingerIndex)
             }
 
+            try self.activeTouches.update(finger: finger, forIdentifier: existingIdentifier)
             return existingIdentifier
         case .ended, .cancelled:
             guard let existingIdentifier = existingIdentifier else {
diff --git a/Sources/Hammer/Utilties/TouchStorage.swift b/Sources/Hammer/Utilties/TouchStorage.swift
index 6b707a5..bb620a1 100644
--- a/Sources/Hammer/Utilties/TouchStorage.swift
+++ b/Sources/Hammer/Utilties/TouchStorage.swift
@@ -54,4 +54,10 @@ struct TouchStorage {
             self.stylusStore = nil
         }
     }
+
+    mutating func update(finger: FingerInfo, forIdentifier identifier: UInt32) throws {
+        if let index = self.fingerStore.firstIndex(where: { $0.identifier == identifier }) {
+            self.fingerStore[index].finger = finger
+        }
+    }
 }
diff --git a/Tests/HammerTests/DragTests.swift b/Tests/HammerTests/DragTests.swift
new file mode 100644
index 0000000..75ca891
--- /dev/null
+++ b/Tests/HammerTests/DragTests.swift
@@ -0,0 +1,24 @@
+import Hammer
+import XCTest
+import Foundation
+
+final class DragTests: XCTestCase {
+
+    func test_drag() throws {
+        let view = TouchTestView()
+
+        view.widthAnchor.constraint(equalToConstant: 300).isActive = true
+        view.heightAnchor.constraint(equalToConstant: 300).isActive = true
+
+        let eventGenerator = try EventGenerator(view: view)
+        try eventGenerator.waitUntilHittable(timeout: 1)
+
+        try eventGenerator.fingerDown(at: view.frame.center.offset(x: -50, y: 0))
+        try eventGenerator.fingerMove(to: view.frame.center.offset(x: 50, y: 0), duration: 0.3)
+        try eventGenerator.fingerUp()
+
+        let endPoint = view.touches.first!.location(in: view)
+        XCTAssertEqual(endPoint, CGPoint(x: 200, y: 150), accuracy: 0.001)
+    }
+
+}
diff --git a/Tests/HammerTests/Utilities/TouchTestView.swift b/Tests/HammerTests/Utilities/TouchTestView.swift
new file mode 100644
index 0000000..fe02490
--- /dev/null
+++ b/Tests/HammerTests/Utilities/TouchTestView.swift
@@ -0,0 +1,13 @@
+import UIKit
+
+final class TouchTestView: UIView {
+
+  var touches: Set<UITouch> = .init()
+
+  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
+    super.touchesBegan(touches, with: event)
+
+    touches.forEach { self.touches.insert($0) }
+  }
+
+}