Best/Up-to-date practice on WKWebView snapshots

[nspassov]

I am trying to snapshot several SwiftUI views, some of which contain a WKWebView subclass. Now I've been trying to follow every piece of advice on the topic, however when the WebView is a subview I can't seem to get the snapshot (I get a test timeout).

Here's the code that works:

            let html = "..."
            let exp1 = XCTestExpectation(description: "webview loaded")
            
            let svgview = WKWebView(frame: CGRect(origin: .zero, size: CGSize(width: 392, height: 852)))
            
            let d = NavigationDelegate()
            d.callback = {
                exp1.fulfill()
            }
            svgview.navigationDelegate = d
            svgview.loadHTMLString(html, baseURL: nil)
            
            await fulfillment(of: [exp1], timeout: 5) // without this, the test would timeout
            
            let failure = verifySnapshot(of: svgview, as: .image)
            // ...

plus the Snapshotting extension:

class NavigationDelegate: NSObject, WKNavigationDelegate {
    var callback: (() -> Void)?
    
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        self.callback?()
    }
}

extension Snapshotting where Value == WKWebView, Format == UIImage {
    public static let image = Snapshotting(
        pathExtension: "png",
        diffing: .image,
        asyncSnapshot: { webView in
            Async { callback in
                let config = WKSnapshotConfiguration()
                config.afterScreenUpdates = false // magical flag, if it's not `false` the test would timeout
                webView.takeSnapshot(with: config) { image, error in
                    if let image = image {
                        callback(image)
                    }
                    if let error = error {
                        print("Could not take snapshot: \(error)")
                    }
                }
            }
        }
    )
}

Using Xcode 16.4, Swift 5.9, swift-snapshot-testing 1.18.4

Any pointers to what changes are needed to get this setup working for any WKWebView subclass that is a subview of the main view being snapshotted?