Async brew fetching.

AsyncBrew.swift

struct Coffee: Hashable {
    let name: String
}

class CoffeeStore: ObservableObject {
    func getCoffee() async -> [Coffee] {
        Thread.sleep(forTimeInterval: 2)
        return [
            Coffee(name: "Cortado"),
            Coffee(name: "Flat White")
        ]
    }
}

struct ContentView: View {
    
    @StateObject var coffeeStore = CoffeeStore()
    @State var coffees: [Coffee] = []
    
    var body: some View {
        List {
            if coffees.isEmpty {
                ProgressView()
                    .progressViewStyle(CircularProgressViewStyle())
                    .frame(maxWidth: .infinity, alignment: .center)
            } else {
                Section("Coffees") {
                    ForEach(coffees, id: \.self) { coffee in
                        Text(coffee.name)
                            .font(.headline)
                    }
                }
            }
        }
        .onAppear {
            loadContent()
        }
    }
    
    private func loadContent() {
        async {
            let coffee = await coffeeStore.getCoffee()
            self.coffees = coffee
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}