Blog: ObservableObjects and Protocols - Use type erasure to workaround Cuckoo mocking issue

blog--observableobject+protocols--cuckoo-workaround-option-2.swift

// Copyright 2021 Expedia, Inc.
// SPDX-License-Identifier: Apache-2.0

import Combine

protocol PriceRequesting {
    
    var price: Price? { get }
    
    var pricePublisher: AnyPublisher<Price?, Never> { get }
    
    func fetch()
}

class PricingProvider: PriceRequesting, ObservableObject {
    
    @Published private(set) var price: Price?
    
    var pricePublisher: AnyPublisher<Price?, Never> {
        return $price.eraseToAnyPublisher()
    }
    
    init(price initialValue: Price? = nil) {
        self.price = initialValue
    }
    
    func fetch() {
        // .. fetch pricing from a service
    }
}