SearchView.swift

struct SearchView: View {
    @ObservedObject var viewModel: SearchViewModel

    var body: some View {
        VStack {
            TextField("Search", text: $viewModel.query)
            List(viewModel.songs) {
                Text($0.name)
            }
        }
    }
}

final class SearchViewModel: ObservableObject {
    @Published var query: String = ""
    @Published private(set) var songs: [Song] = []
    private var cancellable: AnyCancellable?

    init(service: SearchService) {
        cancellable = $query
            .throttle(for: .milliseconds(300), scheduler: DispatchQueue.main, latest: true)
            .removeDuplicates()
            .flatMap {
                service.searchSongs(query: $0).catch {
                    _ in Just([])
                }
            }
            .receive(on: DispatchQueue.main)
            .assign(to: \.songs, on: self)
    }
}

final class SearchService {
    func searchSongs(query: String) -> Future<[Song], Error>
}