Slather logo

Coverage for "LastStepInChainAssembly.swift" : 86.36%

(19 of 22 relevant lines covered)

RouteComposer/Classes/Assemblies/Helpers/LastStepInChainAssembly.swift

1 
//
2 
// RouteComposer
3 
// LastStepInChainAssembly.swift
4 
// https://github.com/ekazaev/route-composer
5 
//
6 
// Created by Eugene Kazaev in 2018-2022.
7 
// Distributed under the MIT license.
8 
//
9 
// Become a sponsor:
10 
// https://github.com/sponsors/ekazaev
11 
//
12
13 
import Foundation
14 
import UIKit
15
16 
/// Helper class to build a chain of steps. Can not be used directly.
17 
public struct LastStepInChainAssembly<ViewController: UIViewController, Context> {
18
19 
    // MARK: Properties
20
21 
    let previousSteps: [RoutingStep]
22
23 
    // MARK: Methods
24
25 
    init(previousSteps: [RoutingStep]) {
 202x
26 
        self.previousSteps = previousSteps
 202x
27 
    }
 202x
28
29 
    /// Assembles all the provided settings.
30 
    ///
31 
    /// - Returns: The instance of `DestinationStep` with all the settings provided inside.
32 
    public func assemble() -> DestinationStep<ViewController, Context> {
 202x
33 
        DestinationStep(chain(previousSteps))
 202x
34 
    }
 202x
35
36 
    private func chain(_ steps: [RoutingStep]) -> RoutingStep {
 202x
37 
        guard let lastStep = steps.last else {
 202x
38 
            preconditionFailure("No steps provided to chain.")
 !
39 
        }
 202x
40
202x
41 
        let firstStep = steps.dropLast().reversed().reduce(lastStep) { result, currentStep in
 248x
42 
            guard var step = currentStep as? BaseStep else {
 248x
43 
                assertionFailure("\(currentStep) can not be chained to non chainable step \(result)")
 !
44 
                return currentStep
 !
45 
            }
 248x
46 
            step.from(result)
 248x
47 
            return step
 248x
48 
        }
 248x
49
202x
50 
        return firstStep
 202x
51 
    }
 202x
52
53 
}