Apple pay unit testing - ios

Question

I'm working with apple pay on iOS 11
I have unit testing for our credit card tokenization. But I'm trying to tokenize an apple pay request.
Is it possible to unit test apple pay?
import XCTest
import PassKit
#testable import os_ios
extension apiTests{
func testBraintreeApplePay(){
let expect = expectation(description: "testBraintreeApplePay")
var responseReceived = false
let number = "4111111111111111"
let month = "12"
let year = "20"
let securityCode = "411"
let postalCode = "70433"
let payment = PKPayment()
// add the above info to this payment
Braintree.paymentAuthorizationViewController(
didAuthorizePayment: payment,
completion: {(status: PKPaymentAuthorizationStatus,nonce:String?) in
responseReceived = true
// Check to see if we've received a nonce
expect.fulfill()
})
waitForExpectations(timeout: expectationTimeoutDuration, handler: nil)
XCTAssert(responseReceived)
}
}

Answer 1

In order to initialize 'PKPaymentAuthorizationController', you need to inject the value that each specific test needs. In the case of Apple Pay, it usually involves the method 'canMakePayments(usingNetworks: [PKPaymentNetwork]) -> Bool' and the failable initializer for the 'PKPaymentAuthorizationController' or 'PKPaymentAuthorizationViewController'.
You can do it either by constructor injection (passing the values on the initializer) or by property injection.
Here's an example of a class that handles authorization controller initialization, and completes with the controller, or completes with an error.
public class PaymentAuthorizationHandler {
public typealias ApplePayControllerFactory = (PKPaymentRequest) -> PKPaymentAuthorizationViewController?
public typealias ApplePayCompletionHandler = (Result<PKPaymentAuthorizationViewController, Error>) -> Void
public typealias NetworkAuthorizationHandler = ([PKPaymentNetwork]) -> Bool
public enum Error: Swift.Error {
case networkNotSupported
case unableToInitialize
}
private let controllerFactory: ApplePayControllerFactory
private let networkAuthorizationHandler: NetworkAuthorizationHandler
public init(
controllerFactory: #escaping ApplePayControllerFactory = PKPaymentAuthorizationViewController.init,
networkAuthorizationHandler: #escaping NetworkAuthorizationHandler = PKPaymentAuthorizationViewController.canMakePayments
) {
self.controllerFactory = controllerFactory
self.networkAuthorizationHandler = networkAuthorizationHandler
}
private func makeRequest() -> PKPaymentRequest { //... }
public func requestAuthorization(completion: ApplePayCompletionHandler) {
let request = makeRequest()
guard networkAuthorizationHandler(request.supportedNetworks) else {
completion(.failure(.networkNotSupported))
return
}
guard let paymentVC = controllerFactory(request) else {
completion(.failure(.unableToInitialize))
return
}
completion(.success(paymentVC))
}
}
The view controller initializer and the 'canMakePayments(usingNetworks: [PKPaymentNetwork]) -> Bool' method signature are being injected via constructor injection, represented by the typealiases. With this change, it’s possible to pass, in production, the real method, and for test use, the value required for the test case can be provided by injecting it during the test setup.
Here's an example of the tests:
func test_requestAuthorization_failsWhenControllerInitializationFails() {
let authController = PKPaymentAuthorizationViewController(paymentRequest: .invalidRequest)
let sut = PaymentAuthorizationHandler(controllerFactory: { request in
authController
}, networkAuthorizationHandler: { networks in
true
})
let exp = expectation(description: "Wait for request permission")
var expectedError: PaymentAuthorizationHandler.Error?
sut.requestAuthorization { response in
switch response {
case let.success(controller):
XCTFail("Expected failure, received \(String(describing: controller)) instead")
case let .failure(receivedError):
expectedError = receivedError
}
exp.fulfill()
}
wait(for: [exp], timeout: 1.0)
XCTAssertEqual(expectedError, .unableToInitialize)
}
func test_requestAuthorization_succeedsWhenPaymentNetworkSupported() {
let authController = PKPaymentAuthorizationViewController(paymentRequest: .validRequest)
let sut = PaymentAuthorizationHandler(controllerFactory: { request in
authController
}, networkAuthorizationHandler: { networks in
true
})
let exp = expectation(description: "Wait for request permission")
sut.requestAuthorization { response in
switch response {
case let.success(receivedController):
XCTAssertNotNil(receivedController, "Request might be incomplete, or payment is not possible")
case let .failure(receivedError):
XCTFail("Expected success, received \(receivedError) instead")
}
exp.fulfill()
}
wait(for: [exp], timeout: 1.0)
}
You can check a more thorough explanation here.