Beam/PreviewTests/PreviewTests.stencil

// swiftlint:disable all
// swiftformat:disable all

import XCTest
import SwiftUI
import Prefire
@testable import SnapshotTesting
#if canImport(AccessibilitySnapshot)
    import AccessibilitySnapshot
#endif
{% if argument.mainTarget %}
@testable import {{ argument.mainTarget }}
{% endif %}
{% for import in argument.imports %}
{% if import != "last" %}
import {{ import }}
{% endif %}
{% endfor %}
{% for import in argument.testableImports %}
{% if import != "last" %}
@testable import {{ import }}
{% endif %}
{% endfor %}

class PreviewTests: XCTestCase {
    private let deviceConfig: ViewImageConfig = .iPhoneX
    private var simulatorDevice: String?{% if argument.simulatorDevice %} = "{{ argument.simulatorDevice|default:nil }}"{% endif %}
    private var requiredOSVersion: Int?{% if argument.simulatorOSVersion %} = {{ argument.simulatorOSVersion }}{% endif %}
    private let snapshotDevices: [String]{% if argument.snapshotDevices %} = {{ argument.snapshotDevices|split:"|" }}{% else %} = []{% endif %}
    
    
    {% if argument.file %}

    private var file: StaticString { .init(stringLiteral: "{{ argument.file }}") }
    {% endif %}

    override func setUp() {
        super.setUp()

        checkEnvironments()
        UIView.setAnimationsEnabled(false)
    }

    // MARK: - PreviewProvider

    {% for type in types.types where (type.implements.PrefireProvider or type.based.PrefireProvider or type|annotated:"PrefireProvider") and type.name != "TestablePreview" %}
    func test_{{ type.name|lowerFirstLetter|replace:"_Previews", "" }}() {
        for preview in {{ type.name }}._allPreviews {
            assertSnapshots(matching: preview)
        }
    }
    {%- if not forloop.last %}

    {% endif %}
    {% endfor %}
    {% if argument.previewsMacros %}
    // MARK: - Macros

    {{ argument.previewsMacros }}
    {% endif %}
    // MARK: Private

    private func assertSnapshots(matching preview: _Preview, testName: String = #function) {
        guard !snapshotDevices.isEmpty else {
            if let failure = assertSnapshots(matching: AnyView(preview.content),
                                             name: preview.displayName,
                                             isScreen: preview.layout == .device,
                                             device: preview.device?.snapshotDevice() ?? deviceConfig,
                                             testName: testName) {
                XCTFail(failure)
            }
            return
        }
        
        for deviceName in snapshotDevices {
            guard var device = PreviewDevice(rawValue: deviceName).snapshotDevice() else {
                fatalError("Unknown device name: \(deviceName)")
            }
            
            // Ignore specific device safe area (using the workaround value to fix rendering issues).
            device.safeArea = .one
            
            // Ignore specific device display scale
            let traits = UITraitCollection(displayScale: 2.0)
            
            if let failure = assertSnapshots(matching: AnyView(preview.content),
                                            name: preview.displayName,
                                            isScreen: preview.layout == .device,
                                            device: device,
                                            testName: testName + deviceName + "-" + localeCode,
                                            traits: traits) {
                XCTFail(failure)
            }
        }
    }
    
    private var localeCode: String {
        if UserDefaults.standard.bool(forKey: "NSDoubleLocalizedStrings") {
            return "pseudo"
        }
        return languageCode + "-" + regionCode
    }

    private var languageCode: String {
        Locale.current.language.languageCode?.identifier ?? ""
    }

    private var regionCode: String {
        Locale.current.language.region?.identifier ?? ""
    }

    private func assertSnapshots(matching view: AnyView,
                                 name: String?, isScreen: Bool,
                                 device: ViewImageConfig,
                                 testName: String = #function,
                                 traits: UITraitCollection = .init()) -> String? {
        var delay: TimeInterval = 0
        var precision: Float = 1
        var perceptualPrecision: Float = 1

        let view = view
            .onPreferenceChange(DelayPreferenceKey.self) { delay = $0 }
            .onPreferenceChange(PrecisionPreferenceKey.self) { precision = $0 }
            .onPreferenceChange(PerceptualPrecisionPreferenceKey.self) { perceptualPrecision = $0 }

        let matchingView = isScreen ? AnyView(view) : AnyView(view
            .frame(width: device.size?.width)
            .fixedSize(horizontal: false, vertical: true)
        )

        let failure = verifySnapshot(
            of: matchingView,
            as: .prefireImage(precision: { precision },
                              perceptualPrecision: { perceptualPrecision },
                              duration: { delay },
                              layout: isScreen ? .device(config: device) : .sizeThatFits,
                              traits: traits),
            named: name{% if argument.file %},
            file: file{% endif %},
            testName: testName
        )

        #if canImport(AccessibilitySnapshot)
            let vc = UIHostingController(rootView: matchingView)
            vc.view.frame = UIScreen.main.bounds
            assertSnapshot(
                matching: vc,
                as: .wait(for: delay, on: .accessibilityImage(showActivationPoints: .always)),
                named: name.flatMap { $0 + ".accessibility" }{% if argument.file %},
                file: file{% endif %},
                testName: testName
            )
        #endif
        return failure
    }

    /// Check environments to avoid problems with snapshots on different devices or OS.
    private func checkEnvironments() {
        if let simulatorDevice {
            let deviceModel = ProcessInfo().environment["SIMULATOR_MODEL_IDENTIFIER"]
            guard deviceModel?.contains(simulatorDevice) ?? false else {
                fatalError("\(deviceModel ?? "Unknown") is the wrong one. Switch to using \(simulatorDevice) for these tests.")
            }
        }

        if let requiredOSVersion {
            let osVersion = ProcessInfo().operatingSystemVersion
            guard osVersion.majorVersion == requiredOSVersion else {
                fatalError("Switch to iOS \(requiredOSVersion) for these tests.")
            }
        }
    }
}

// MARK: - SnapshotTesting + Extensions

private extension PreviewDevice {
    func snapshotDevice() -> ViewImageConfig? {
        switch rawValue {
        case "iPhone 15", "iPhone 14", "iPhone 13", "iPhone 12", "iPhone 11", "iPhone 10":
            return .iPhoneX
        case "iPhone 6", "iPhone 6s", "iPhone 7", "iPhone 8":
            return .iPhone8
        case "iPhone 6 Plus", "iPhone 6s Plus", "iPhone 8 Plus":
            return .iPhone8Plus
        case "iPhone SE (1st generation)", "iPhone SE (2nd generation)":
            return .iPhoneSe
        case "iPad":
            return .iPad10_2
        case "iPad Mini":
            return .iPadMini
        case "iPad Pro 11":
            return .iPadPro11
        case "iPad Pro 12.9":
            return .iPadPro12_9
        default: return nil
        }
    }
}

private extension Snapshotting where Value: SwiftUI.View, Format == UIImage {
    static func prefireImage(
        drawHierarchyInKeyWindow: Bool = false,
        precision: @escaping () -> Float,
        perceptualPrecision: @escaping () -> Float,
        duration: @escaping () -> TimeInterval,
        layout: SwiftUISnapshotLayout = .sizeThatFits,
        traits: UITraitCollection = .init()
    ) -> Snapshotting {
        let config: ViewImageConfig

        switch layout {
        #if os(iOS) || os(tvOS)
        case let .device(config: deviceConfig):
            config = deviceConfig
        #endif
        case .sizeThatFits:
            // Make sure to use the workaround safe area insets.
            config = .init(safeArea: .one, size: nil, traits: traits)
        case let .fixed(width: width, height: height):
            let size = CGSize(width: width, height: height)
            // Make sure to use the workaround safe area insets.
            config = .init(safeArea: .one, size: size, traits: traits)
        }

        return SimplySnapshotting<UIImage>(pathExtension: "png", diffing: .prefireImage(precision: precision, perceptualPrecision: perceptualPrecision, scale: traits.displayScale))
            .asyncPullback { view in
                var config = config

                let controller: UIViewController

                if config.size != nil {
                    controller = UIHostingController(rootView: view)
                } else {
                    let hostingController = UIHostingController(rootView: view)

                    let maxSize = CGSize.zero
                    config.size = hostingController.sizeThatFits(in: maxSize)

                    controller = hostingController
                }

                return Async<UIImage> { callback in
                    let strategy = snapshotView(
                        config: config,
                        drawHierarchyInKeyWindow: drawHierarchyInKeyWindow,
                        traits: traits,
                        view: controller.view,
                        viewController: controller
                    )

                    let duration = duration()
                    if duration != .zero {
                        let expectation = XCTestExpectation(description: "Wait")
                        DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
                            expectation.fulfill()
                        }
                        _ = XCTWaiter.wait(for: [expectation], timeout: duration + 1)
                    }
                    strategy.run(callback)
                }
            }
    }
}

private extension Diffing where Value == UIImage {
    static func prefireImage(precision: @escaping () -> Float, perceptualPrecision: @escaping () -> Float, scale: CGFloat?) -> Diffing {
        lazy var originalDiffing = Diffing.image(precision: precision(), perceptualPrecision: 0.98, scale: scale)
        return Diffing(
            toData: { originalDiffing.toData($0) },
            fromData: { originalDiffing.fromData($0) },
            diff: { originalDiffing.diff($0, $1) }
        )
    }
}

private extension UIEdgeInsets {
    /// A custom inset that prevents the snapshotting library from rendering the
    /// origin at (10000, 10000) which breaks some of our views such as MessageText.
    static var one: UIEdgeInsets { UIEdgeInsets(top: 1, left: 1, bottom: 1, right: 1) }
}

// swiftlint:enable all
// swiftformat:enable all