Implement timeout for Risk SDK

Author: okhan-okbay-cko

Checkout/Source/Tokenisation/CheckoutAPIService.swift

@@ -145,6 +145,10 @@ final public class CheckoutAPIService: CheckoutAPIProtocol {
     }
   }
 
+  let timeoutInterval: TimeInterval = 3
+  private let taskCompletionQueue = DispatchQueue(label: "taskCompletionQueue", qos: .userInitiated)
+  private var isTaskCompleted = false
+
   private func createToken(requestParameters: NetworkManager.RequestParameters,
                            paymentType: TokenRequest.TokenType,
                            completion: @escaping (Result<TokenDetails, TokenisationError.TokenRequest>) -> Void) {
@@ -164,19 +168,10 @@ final public class CheckoutAPIService: CheckoutAPIProtocol {
           return
         }
 
-        self.riskSDK.configure { configurationResult in
-              switch configurationResult {
-              case .failure:
-                  completion(.success(tokenDetails))
-                  logManager.resetCorrelationID()
-              case .success():
-                  self.riskSDK.publishData(cardToken: tokenDetails.token) { _ in
-                      logManager.queue(event: .riskSDKCompletion)
-                      completion(.success(tokenDetails))
-                      logManager.resetCorrelationID()
-                  }
-              }
-          }
+        self.callRiskSDK(tokenDetails: tokenDetails) {
+          completion(.success(tokenDetails))
+        }
+
       case .errorResponse(let errorResponse):
         completion(.failure(.serverError(errorResponse)))
         logManager.resetCorrelationID()
@@ -187,6 +182,47 @@ final public class CheckoutAPIService: CheckoutAPIProtocol {
     }
   }
 
+  private func callRiskSDK(tokenDetails: TokenDetails,
+                           completion: @escaping () -> Void) {
+
+    /* Risk SDK calls can be finalised in 3 different ways
+     1. When Risk SDK's configure(...) function completed successfully and publishData(...) completed successfully or not
+     2. When Risk SDK's configure(...) function completed with failure
+     3. When Risk SDK's configure(...) or publishData(...) functions hang and don't call their completion blocks.
+        In this case, we wait for `self.timeoutInterval` amount of time and call the completion block anyway.
+
+     All these operations are done synchronously to avoid the completion closure getting called multiple times.
+    */
+
+    let finaliseRiskSDKCalls = {
+      self.taskCompletionQueue.sync {
+        if !self.isTaskCompleted {
+          self.isTaskCompleted = true
+          completion()
+        }
+      }
+    }
+
+    DispatchQueue.global(qos: .userInitiated).asyncAfter(deadline: .now() + timeoutInterval) {
+      finaliseRiskSDKCalls()
+    }
+
+    self.riskSDK.configure { [weak self] configurationResult in
+      guard let self else { return }
+      switch configurationResult {
+      case .failure:
+        finaliseRiskSDKCalls()
+        logManager.resetCorrelationID()
+      case .success():
+        self.riskSDK.publishData(cardToken: tokenDetails.token) { _ in
+          self.logManager.queue(event: .riskSDKCompletion)
+          finaliseRiskSDKCalls()
+          self.logManager.resetCorrelationID()
+        }
+      }
+    }
+  }
+
   private func logTokenResponse(tokenResponseResult: NetworkRequestResult<TokenResponse, TokenisationError.ServerError>,
                                 paymentType: TokenRequest.TokenType,
                                 httpURLResponse: HTTPURLResponse?) {

CheckoutTests/Stubs/StubRisk.swift

@@ -14,15 +14,24 @@ class StubRisk: RiskProtocol {
 
     var configureCalledCount = 0
     var publishDataCalledCount = 0
-    
+
+    // If set to false, Risk SDK will hang and not call the completion block for that specific function.
+    // It will mimic the behaviour of a bug we have. We need to call Frames's completion block after the defined timeout period in that case.
+    var shouldConfigureFunctionCallCompletion: Bool = true
+    var shouldPublishFunctionCallCompletion: Bool = true
+
     func configure(completion: @escaping (Result<Void, RiskError.Configuration>) -> Void) {
         configureCalledCount += 1
-        completion(.success(()))
+        if shouldConfigureFunctionCallCompletion {
+          completion(.success(()))
+        }
     }
 
     func publishData (cardToken: String? = nil, completion: @escaping (Result<PublishRiskData, RiskError.Publish>) -> Void) {
         publishDataCalledCount += 1
-        completion(.success(PublishRiskData(deviceSessionId: "dsid_testDeviceSessionId")))
+        if shouldPublishFunctionCallCompletion {
+          completion(.success(PublishRiskData(deviceSessionId: "dsid_testDeviceSessionId")))
+        }
     }
 }
 

CheckoutTests/Tokenisation/CheckoutAPIServiceTests.swift

@@ -354,3 +354,67 @@ extension CheckoutAPIServiceTests {
       }
   }
 }
+
+// Risk SDK Timeout Recovery Tests
+extension CheckoutAPIServiceTests {
+  func testWhenRiskSDKCallsCompletionThenFramesReturnsSuccess() {
+    let card = StubProvider.createCard()
+    let tokenRequest = StubProvider.createTokenRequest()
+    let requestParameters = StubProvider.createRequestParameters()
+    let tokenResponse = StubProvider.createTokenResponse()
+    let tokenDetails = StubProvider.createTokenDetails()
+
+    stubTokenRequestFactory.createToReturn = .success(tokenRequest)
+    stubRequestFactory.createToReturn = .success(requestParameters)
+    stubTokenDetailsFactory.createToReturn = tokenDetails
+
+    var result: Result<TokenDetails, TokenisationError.TokenRequest>?
+    subject.createToken(.card(card)) { result = $0 }
+    stubRequestExecutor.executeCalledWithCompletion?(.response(tokenResponse), HTTPURLResponse())
+
+    XCTAssertEqual(stubRisk.configureCalledCount, 1)
+    XCTAssertEqual(stubRisk.publishDataCalledCount, 1)
+    XCTAssertEqual(result, .success(tokenDetails))
+  }
+
+  func testWhenRiskSDKConfigureHangsThenFramesSDKCancelsWaitingRiskSDKAndCallsCompletionBlockAnywayAfterTimeout() {
+    stubRisk.shouldConfigureFunctionCallCompletion = false // Configure function will hang forever before it calls its completion closure
+    verifyRiskSDKTimeoutRecovery(timeoutAddition: 1, expectedConfigureCallCount: 1, expectedPublishDataCallCount: 0)
+  }
+
+  func testWhenRiskSDKPublishHangsThenFramesSDKCancelsWaitingRiskSDKAndCallsCompletionBlockAnywayAfterTimeout() {
+    stubRisk.shouldPublishFunctionCallCompletion = false // Publish data function will hang forever before it calls its completion closure
+    verifyRiskSDKTimeoutRecovery(timeoutAddition: 1, expectedConfigureCallCount: 1, expectedPublishDataCallCount: 1)
+  }
+
+  func verifyRiskSDKTimeoutRecovery(timeoutAddition: Double,
+                                    expectedConfigureCallCount: Int,
+                                    expectedPublishDataCallCount: Int,
+                                    file: StaticString = #file,
+                                    line: UInt = #line) {
+    let card = StubProvider.createCard()
+    let tokenRequest = StubProvider.createTokenRequest()
+    let tokenResponse = StubProvider.createTokenResponse()
+    let requestParameters = StubProvider.createRequestParameters()
+    let tokenDetails = StubProvider.createTokenDetails()
+
+    stubTokenRequestFactory.createToReturn = .success(tokenRequest)
+    stubRequestFactory.createToReturn = .success(requestParameters)
+    stubTokenDetailsFactory.createToReturn = tokenDetails
+
+    let expectation = self.expectation(description: "Frames will time out awaiting Risk SDK result")
+
+    var _: Result<TokenDetails, TokenisationError.TokenRequest>?
+    subject.createToken(.card(card)) {
+
+      XCTAssertEqual(self.stubRisk.configureCalledCount, expectedConfigureCallCount, file: file, line: line)
+      XCTAssertEqual(self.stubRisk.publishDataCalledCount, expectedPublishDataCallCount, file: file, line: line)
+      XCTAssertEqual($0, .success(tokenDetails), file: file, line: line)
+
+      expectation.fulfill()
+    }
+    stubRequestExecutor.executeCalledWithCompletion?(.response(tokenResponse), HTTPURLResponse())
+
+    waitForExpectations(timeout: subject.timeoutInterval + timeoutAddition)
+  }
+}