Add motion policy tests and fix settings pane height

ComputerSolitaire/Views/MacSettingsView.swift

@@ -10,7 +10,7 @@ import SwiftUI
 struct MacSettingsView: View {
     private enum PaneMetrics {
         static let width: CGFloat = 500
-        static let generalHeight: CGFloat = 410
+        static let generalHeight: CGFloat = 355
         static let appearanceHeight: CGFloat = 560
         static let rulesHeight: CGFloat = 500
         static let aboutHeight: CGFloat = 400

ComputerSolitaireTests/Shared/MotionPolicyTests.swift

@@ -0,0 +1,73 @@
+import XCTest
+@testable import Computer_Solitaire
+
+/// The motion policy is the single gate every gameplay animation and
+/// completion delay routes through; these tests pin its contract — the speed
+/// catalog's stored scales, the raw-value fallback that protects old saved
+/// defaults, the Reduce Motion clamp, and the builders going nil (apply
+/// without animating) whenever motion is off.
+@MainActor
+final class MotionPolicyTests: XCTestCase {
+    func testAnimationSpeedScales() {
+        XCTAssertEqual(AnimationSpeed.normal.scale, 1)
+        XCTAssertEqual(AnimationSpeed.fast.scale, 0.5)
+        XCTAssertEqual(AnimationSpeed.instant.scale, 0)
+        XCTAssertEqual(AnimationSpeed.defaultValue, .normal)
+    }
+
+    func testFromRawValueRoundTripsEveryOption() {
+        for speed in AnimationSpeed.all {
+            XCTAssertEqual(AnimationSpeed.from(rawValue: speed.id), speed)
+        }
+    }
+
+    func testFromRawValueFallsBackToDefaultOnUnknownID() {
+        XCTAssertEqual(AnimationSpeed.from(rawValue: "warp"), .normal)
+        XCTAssertEqual(AnimationSpeed.from(rawValue: ""), .normal)
+    }
+
+    func testPolicyUsesSpeedScaleWithoutReduceMotion() {
+        for speed in AnimationSpeed.all {
+            let policy = MotionPolicy(speed: speed, reduceMotion: false)
+            XCTAssertEqual(policy.scale, speed.scale)
+        }
+    }
+
+    func testReduceMotionClampsEverySpeedToInstant() {
+        for speed in AnimationSpeed.all {
+            let policy = MotionPolicy(speed: speed, reduceMotion: true)
+            XCTAssertEqual(policy.scale, 0)
+            XCTAssertTrue(policy.isInstant)
+            XCTAssertNil(policy.spring(response: 0.35, dampingFraction: 0.86))
+        }
+    }
+
+    func testIsInstantOnlyForZeroScale() {
+        XCTAssertFalse(MotionPolicy(speed: .normal, reduceMotion: false).isInstant)
+        XCTAssertFalse(MotionPolicy(speed: .fast, reduceMotion: false).isInstant)
+        XCTAssertTrue(MotionPolicy(speed: .instant, reduceMotion: false).isInstant)
+    }
+
+    func testDurationScalesWithSpeed() {
+        XCTAssertEqual(MotionPolicy(speed: .normal, reduceMotion: false).duration(0.32), 0.32)
+        XCTAssertEqual(MotionPolicy(speed: .fast, reduceMotion: false).duration(0.32), 0.16)
+        XCTAssertEqual(MotionPolicy(speed: .instant, reduceMotion: false).duration(0.32), 0)
+        XCTAssertEqual(MotionPolicy(speed: .normal, reduceMotion: true).duration(0.32), 0)
+    }
+
+    func testBuildersReturnAnimationsWhenMotionIsOn() {
+        for speed in [AnimationSpeed.normal, .fast] {
+            let policy = MotionPolicy(speed: speed, reduceMotion: false)
+            XCTAssertNotNil(policy.spring(response: 0.35, dampingFraction: 0.86))
+            XCTAssertNotNil(policy.easeOut(0.2))
+            XCTAssertNotNil(policy.easeInOut(0.32))
+        }
+    }
+
+    func testBuildersReturnNilWhenInstant() {
+        let policy = MotionPolicy(speed: .instant, reduceMotion: false)
+        XCTAssertNil(policy.spring(response: 0.35, dampingFraction: 0.86))
+        XCTAssertNil(policy.easeOut(0.2))
+        XCTAssertNil(policy.easeInOut(0.32))
+    }
+}