Eliminate animation hitches with XCTest

6:35 - Create an animation os_signpost interval

os_signpost(.animationBegin, log: logHandle, name: "performAnimationInterval")
os_signpost(.end, log: logHandle, name: "performAnimationInterval")

6:55 - Use a UIKit instrumented animation os_signpost interval

extension XCTOSSignpostMetric {
     open class var navigationTransitionMetric: XCTMetric { get }
     open class var customNavigationTransitionMetric: XCTMetric { get }
     open class var scrollDecelerationMetric: XCTMetric { get }
     open class var scrollDraggingMetric: XCTMetric { get }
}

7:12 - Measure scrolling animation performance using a Performance XCTest

// Measure scrolling animation performance using a Performance XCTest
func testScrollingAnimationPerformance() throws {
    app.launch()
    app.staticTexts["Meal Planner"].tap()
    let foodCollection = app.collectionViews.firstMatch
    
    measure(metrics: [XCTOSSignpostMetric.scrollDecelerationMetric]) {
        foodCollection.swipeUp(velocity: .fast)
    }
}

8:02 - Reset the application state between runs

func testScrollingAnimationPerformance() throws { 
    app.launch()
    app.staticTexts["Meal Planner"].tap()
    let foodCollection = app.collectionViews.firstMatch

    let measureOptions = XCTMeasureOptions()
    measureOptions.invocationOptions = [.manuallyStop]
        
    measure(metrics: [XCTOSSignpostMetric.scrollDecelerationMetric],
            options: measureOptions) {
        foodCollection.swipeUp(velocity: .fast)
        stopMeasuring()
        foodCollection.swipeDown(velocity: .fast)
    }
}