how can I add a border with a cornerRadius to an Image. I get a deprecation warning saying that i should use a RoundedRectange Shape, but i don't know how to use that exactly

Beta 4:

Image(uiImage: ...)
   .border(Color.black, width: 2, cornerRadius: 10)

SwiftUI 5.0

Using clipShape & overlay Modifiers

Here is another way in which we can use a clipShape modifier (which clips the view) and then overlay a stroke with a color.

VStack(spacing: 40) {
    Text("Image Border").font(.largeTitle)
    Text("Using cornerRadius & overlay").font(.title).foregroundColor(.gray)
    Text("Using cornerRadius will also clip the image. Then overlay a border.")
        .frame(maxWidth: .infinity)
        .font(.title)
        .padding()
        .background(Color.orange)
        .foregroundColor(.black)
    
    Image("profile")
        .clipShape(.rect(cornerRadius: 10))
        .overlay(.rect(cornerRadius: 10)
            .stroke(Color.orange, lineWidth: 4))
        .shadow(radius: 10)
}

Result