Crash on route index access

[emartinson]

Sometimes I get crash on

 mutating func dismiss(count: Int = 1) {
    assert(count >= 0)
    var index = endIndex - 1
    var dismissed = 0
    while dismissed < count, index + 1 > rootIndex {
      if self[index].isPresented {
        dismissed += 1
      }
      index -= 1
    }
    goBackTo(index: index)
  }

I suggest to use

self[safe: index]?.isPresented == true instead

extension Collection {
    /// Returns the element at the specified index if it is within bounds, otherwise nil.
    subscript(safe index: Index) -> Element? {
        indices.contains(index) ? self[index] : nil
    }
}

this will eliminate crashes.

Workaround - I do preconditions check on app side for now