The background color of SecondView doesn’t change as expected when I push the button, however, the random number in ThirdView updates each time. Why does this happen, both secondView and thirdView have no explicit dependency on the state, I think both of them should not be re-created.

Apple Docs: When the @State value changes, SwiftUI updates the parts of the view hierarchy that depend on the value.

struct ParentView: View {
    @State var counter: Int = 0

    var body: some View {
        VStack {
            Text("ContentView (counter)")
            SecondView()
            ThirdView()
            Button {
                counter += 1
            } label: {
                Text("Go!")
            }
        }
    }
}

struct SecondView: View {
    var body: some View {
        Text("SecondView")
            .background(.debug)
    }
}

struct ThirdView: View {
  let randomNumber = Int.random(in: 1...100)
  var body: some View {
    Text("Random Number: (randomNumber)")
  }
}


public extension ShapeStyle where Self == Color {
    static var debug: Color {
        Color(
            red: .random(in: 0...1),
            green: .random(in: 0...1),
            blue: .random(in: 0...1)
        )
    }
}