AffineTransform: implement hashValue and improve tests (#1212)

* NSAffineTransform: implement hashValue and enable tests

* AffineTransform: add rotation test

Author: ianpartridge

Foundation/AffineTransform.swift

@@ -338,6 +338,10 @@ open class NSAffineTransform : NSObject, NSCopying, NSSecureCoding {
         return other === self
             || (other.transformStruct == self.transformStruct)
     }
+
+    open override var hashValue: Int {
+        return transformStruct.hashValue
+    }
 
     public static var supportsSecureCoding: Bool {
         return true

TestFoundation/TestAffineTransform.swift

@@ -38,6 +38,9 @@ class TestAffineTransform : XCTestCase {
             ("test_AppendTransform", test_AppendTransform),
             ("test_PrependTransform", test_PrependTransform),
             ("test_TransformComposition", test_TransformComposition),
+            ("test_hashing_identity", test_hashing_identity),
+            ("test_hashing_values", test_hashing_values),
+            ("test_rotation_compose", test_rotation_compose),
             ("test_Equal", test_Equal),
             ("test_NSCoding", test_NSCoding),
         ]
@@ -345,6 +348,16 @@ class TestAffineTransform : XCTestCase {
             XCTAssertEqual(ref.hashValue, val.hashValue)
         }
     }
+
+    func test_rotation_compose() {
+        var t = AffineTransform.identity
+        t.translate(x: 1.0, y: 1.0)
+        t.rotate(byDegrees: 90)
+        t.translate(x: -1.0, y: -1.0)
+        let result = t.transform(NSPoint(x: 1.0, y: 2.0))
+        XCTAssertEqual(0.0, Double(result.x), accuracy: accuracyThreshold)
+        XCTAssertEqual(1.0, Double(result.y), accuracy: accuracyThreshold)
+    }
 
     func test_Equal() {
         let transform = NSAffineTransform()