Have you ever dealt with writing tests using snapshot testing?

Yes, snapshot testing in iOS is typically used to verify the visual state of UI components. The idea is that on the first run, a snapshot of the interface is saved, and on subsequent runs, it is compared to the current state. If there are discrepancies, the test fails, which helps quickly identify unwanted UI changes.

Example of usage with the iOS Snapshot Testing library:

import SnapshotTesting
import XCTest

class MyViewTests: XCTestCase {
    func testMyViewSnapshot() {
        let view = MyCustomView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
        assertSnapshot(matching: view, as: .image)
    }
}

This approach is convenient for controlling visual regressions, especially when working with custom interface elements.