无法为 UI 测试调整日期选择器的值：类型 6 的 PickerWheel

Question

我们正在使用 XCTest 框架为我们的 iOS 应用编写 UI 自动化，我们必须使用日期选择器 select 日期。 使用 iOS 13，我们使用 adjust() 方法来设置日期选择器的值。 但是对于 iOS 14，当我们尝试将 datepicker 的值设置如下时

element.adjust(toPickerWheelValue: "September")

我收到以下错误

Unsupported picker wheel "2020" PickerWheel of type 6

其他人已在 https://developer.apple.com/forums/thread/661809 上发布了类似问题。

有人遇到过这个问题吗？

Answer 1

从 Xcode 12.1 开始，似乎仍然没有支持更改新日期选择器轮的方法。

我想出了这个方法来解决这个问题：

func adjustDatePicker(wheel: XCUIElement, to newValue: String) -> Bool {    
    let x = wheel.frame.width / 2.0
    let y = wheel.frame.height / 2.0
    // each wheel notch is about 30px high, so tapping y - 30 rotates up. y + 30 rotates down.
    var offset: CGFloat = -30.0
    var reversed = false
    let previousValue = wheel.value as? String
    while wheel.value as? String != newValue {
        wheel.coordinate(withNormalizedOffset: .zero).withOffset(CGVector(dx: x, dy: y + offset)).tap()
        let briefWait = expectation(description: "Wait for wheel to rotate")
        briefWait.isInverted = true
        wait(for: [briefWait], timeout: 0.25)
        if previousValue == wheel.value as? String {
            if reversed {
                // we already tried reversing, can't find the desired value
                break
            }
            // we didn't move the wheel. try reversing direction
            offset = 30.0
            reversed = true
        }
    }
    
    return wheel.value as? String == newValue
}

Answer 2

import Foundation
import XCTest

struct ScrollParameters {
    let halfX: CGFloat
    let dy: CGFloat
    let tapCount: Int
    
    // how many notches to rotate with one tap
    let notchCountToRotate: Int
    
    // To rotate n notches with one tap, we have to multiply notch height with nth value in following array
    // e.g. To rotate 3 notches, multiply notch height with 2.7
    static let reverseScrollingOffset:[CGFloat] = [0, 1, 2, 2.7]
    static let forwardScrollingOffset:[CGFloat] = [0, 1, 2, 2.5]
    
    // each wheel notch is about 30px high, so tapping y - 30 rotates up. y + 30 rotates down.
    static let wheelNotchHeight:CGFloat = 30.0
    
    static let maxAttempts = 50
}

/// Given the number of notches to be rotated with one tap, this function determines how many taps are required in order to minimize the difference between current picker value and the value to be set.
private func calculateTapCount(forZeroing difference: Int, withNotchRotationCount notchRotationCount: Int) -> Int {
    if difference == 0 {
        return 0
    }
    let positiveDiff = difference < 0 ? (difference * -1) : difference
    return positiveDiff / notchRotationCount
}

private func scroll(_ wheel: XCUIElement, with scrollParams: ScrollParameters) {
    var currentTapCount = 0
    while currentTapCount < scrollParams.tapCount {
        wheel.coordinate(withNormalizedOffset: .zero)
            .withOffset(CGVector(dx: scrollParams.halfX, dy: scrollParams.dy))
            .tap()
        currentTapCount += 1
    }
}

/// Determines number of notches to be rotated with one tap.
private func getNotchRotationCountWithOneTap(_ difference: Int) -> Int {
    if difference == 0 {
        return 0
    }
    
    if (difference >= 3) || (difference <= -3) {
        return 3
    }
    
    return (difference % 2 == 0) ? 2 : 1
}

/// Returns the y-axis offset required for rotating n notches of pickerwheel with 1 tap.
/// The offset values are stored in static arrays in ScrollParameters.
/// If we want to rotate the wheel in reverse direction, we have to subtract the offset from center coordinate.
/// Hence, offset value is multiplied by -1.
private func getTappingOffset(_ difference: Int, _ notchRotationCountForOneTap: Int) -> CGFloat {
    if difference > 0 {
        return ScrollParameters.reverseScrollingOffset[notchRotationCountForOneTap] * (-1.0)
    } else {
        return ScrollParameters.forwardScrollingOffset[notchRotationCountForOneTap]
    }
}

/// Returns the metadata for rotating pickerwheel notches.
private func getRotationMetadata(for difference: Int, with wheel:XCUIElement) -> ScrollParameters {
    let notchRotationCountForOneTap = getNotchRotationCountWithOneTap(difference) // 0, 1, 2, 3
    let tapCount = calculateTapCount(forZeroing: difference, withNotchRotationCount: notchRotationCountForOneTap)
    let halfX:CGFloat = wheel.frame.width / 2.0
    let halfY:CGFloat = wheel.frame.height / 2.0
    let dy:CGFloat = halfY + (ScrollParameters.wheelNotchHeight * getTappingOffset(difference, notchRotationCountForOneTap))
    return ScrollParameters(halfX: halfX, dy: dy, tapCount: tapCount, notchCountToRotate: notchRotationCountForOneTap)
}

private func getYearWheelValue(_ wheel: XCUIElement) -> Int {
    sleep(for: 250) //will sleep for 250 milliseconds (.025 seconds)
    return Int(wheel.value as! String)!
}

private func setYear(_ wheel: XCUIElement, _ yearToSet: Int) {
    var pickerWheelValue = getYearWheelValue(wheel)
    var counter = 0
    repeat {
        let diff = pickerWheelValue - yearToSet
        let scrollParams = getRotationMetadata(for: diff, with: wheel)
        scroll(wheel, with: scrollParams)
        pickerWheelValue = getYearWheelValue(wheel)
        counter += 1
    } while (pickerWheelValue != yearToSet) && (counter < ScrollParameters.maxAttempts)
}

private func getMonthWheelIndex(_ wheel: XCUIElement) -> Int {
    sleep(for: 250)
    let pickerValue = wheel.value as! String
    let monthNames:[String] = DateFormatter().monthSymbols
    return monthNames.firstIndex(of: pickerValue)!
}
 
private func selectMonth(_ wheel: XCUIElement, _ valueToSet: Int) {
    let expectedValueIndex = valueToSet - 1
    var pickerValueIndex: Int = getMonthWheelIndex(wheel)
    var counter = 0
    repeat {
        let diff = pickerValueIndex - expectedValueIndex
        let scrollParams = getRotationMetadata(for: diff, with: wheel)
        scroll(wheel, with: scrollParams)
        pickerValueIndex = getMonthWheelIndex(wheel)
        counter += 1
    } while (pickerValueIndex != expectedValueIndex) && (counter < ScrollParameters.maxAttempts)
}

private func getButtonForDay(with predicateForDayButton: NSPredicate) -> XCUIElement? {
    let datepicker = GlobalTestContext.shared.app?.datePickers.element(boundBy: 1)
    let buttons = datepicker?.buttons.allElementsBoundByIndex
    for button in buttons! {
        let query = button.descendants(matching: .staticText).matching(predicateForDayButton)
        if query.count == 1 {
            return button
        }
    }
    XCTAssertFalse(true, "No matching day found in the datepicker")
    return nil
}

private func selectDay(_ day: Int) {
    let predicateForDayButton = NSPredicate(format: "label == %@", String(describing: day))
    let dayButton = getButtonForDay(with: predicateForDayButton)
    dayButton?.tap()
}
 
private func dismissDatePicker(_ app: XCUIApplication) {
    let start = app.coordinate(withNormalizedOffset: CGVector(dx: 1.0, dy: 0.8))
    // tapping bottom right corner to dismiss the datepicker
    let end = app.coordinate(withNormalizedOffset: CGVector(dx: 1.0, dy: 1.0))
    start.press(forDuration: 0.1, thenDragTo: end)
}
 
func isNewDatePicker(_ datePicker: XCUIElement) -> Bool {
    return datePicker.pickerWheels.count == 0
}

// entry point 
func setDateInNewDatepicker(_ datePicker: XCUIElement, _ dateComponents: DateComponents) -> Any {
    let app = XCUIApplication()
    app.descendants(matching: .other).matching(identifier: "Date Picker").element.tap()
    app.descendants(matching: .button).matching(identifier: "Show year picker").element.tap()
    
    let yearPicker = (app.descendants(matching: .pickerWheel).element(boundBy: 1))
    setYear(yearPicker, dateComponents.year!)
    
    let monthPicker = (app.descendants(matching: .pickerWheel).element(boundBy: 0))
    selectMonth(monthPicker, dateComponents.month!)
    
    app.descendants(matching: .button).matching(identifier: "Hide year picker").element.tap()
    
    selectDay(dateComponents.day!)
    dismissDatePicker(app)
    return datePicker
}