PreviewProvider.stencil

import SwiftUI
import SnapshotTesting
import XCTest
@testable import SnapshotArticle

private func assertPreviewSnapshot<T: PreviewProvider>(_ target: T.Type,
                                                       file: StaticString = #file,
                                                       testName: String = #function,
                                                       line: UInt = #line,
                                                       isDarkMode: Bool = false) {
    for preview in T._allPreviews {
        let content = preview.content
        let viewController = content.toViewController()
        if isDarkMode {
            viewController.overrideUserInterfaceStyle = .dark
        }
        assertSnapshot(matching: viewController,
                       as: .image(on: .iPhone13),
                       file: file,
                       testName: testName,
                       line: line)
    }
}

class PreviewSnapshotTests: XCTestCase {
{% for type in types.based.PreviewProvider %}
    func test{{type.name}}() {
        assertPreviewSnapshot({{type.name}}.self)
    }

    func test{{type.name}}_dark() {
        assertPreviewSnapshot({{type.name}}.self, isDarkMode: true)
    }

{% endfor %}
}