how_unit_testing_can_help_write_better_designs_8.swift

final class KeyValueStoreSpy: KeyValueStoring {

    // MARK: - Records

    private(set) var keyRecords = [String]()

    private(set) var valueRecords = [StoreValueRepresentable]()

    // MARK: - Stubs

    var getEntryResultStub: [String: Result<Any?, MovieStoreError>]()

    // MARK: - Implementation

    func getValue<Value: StoreValueRepresentable>(for key: String, completion: @escaping (Result<Value?, StoreError>) -> Void) {
        keyRecords.append(key)
        completion(completionResultStub)
    }

    func set(value: StoreValueRepresentable, for key: String) {
        valueRecords.append(value)
        keyRecords.append(key)
    }
}

final class ClientSpy: ClientProtocol {

    // MARK: - Records

    private(set) var pathRecords = [String]()

    // MARK: - Stubs

    var getResultStub = [String: Result<Any, ClientError>]()

    // MARK: - Implementation

    func get<Model: Decodable>(path: String, completion: @escaping (Result<Model, ClientError>) -> Void) {
        pathRecords.append(path)

        let result = getResultStub[path] as! Result<Model, ClientError>
        completion(result)
    }
}