Issues running asynchronous code in unit tests - swift

Question

So I am having issues running asynchronous code in the unit tests of my app. I am using expectations in order to wait for the code to execute before the test completes. The asynchronous code runs through heroku in order to get the values and then should return them in the app. With this unit test, I am trying to make sure the connection through heroku is working. Here is a look at my code:
func test() {
let url = "https://s.herokuapp.com/test"
let params: [String: Any] = ["account_id": AppState.sharedInstance.user.accounttoken]
let expectation = self.expectation(description: "Testing returning value")
let totalBalance = ""
Alamofire.request(url, method: .post, parameters: params)
.validate(statusCode: 200..<300)
.responseJSON { response in
switch response.result {
case .success:
print("Returned with success")
case .failure(let error):
let status = response.response?.statusCode
print("Failed, status: \(status)")
print("Here is the error: \(error)")
}
if let result = response.result.value {
let balance = result as! NSDictionary
let totalBalance = String(describing: "\(balance["Balance"]!)")
}
XCTAssert(totalBalance != "")
expectation.fulfill()
}
waitForExpectations(timeout: 10, handler: nil)
XCTAssert(totalBalance != "")
}
The reason I am confused is because I have no error getting the asynchronous code to return values in the actual app. I only have the wait time issue in unit testing. I am getting two fail errors, one for the XCTAssert not being true and one for the waitForExpectations going longer than 10 seconds. Here is some of the errors that are popping up as well if that helps find the solution:
Here is the error messages in text form:
2019-07-01 09:44:38.181971-0400 Spotbirdparking[49677:4306598] TIC TCP
Conn Failed [6:0x6000030b7cc0]: 3:-9816 Err(-9816) 2019-07-01
09:44:38.188607-0400 Spotbirdparking[49677:4306598]
NSURLSession/NSURLConnection HTTP load failed
(kCFStreamErrorDomainSSL, -9816) 2019-07-01 09:44:38.188819-0400
Spotbirdparking[49677:4306598] Task
.<1> HTTP load failed (error
code: -1200 [3:-9816]) 2019-07-01 09:44:38.189215-0400
Spotbirdparking[49677:4306623] Task
.<1> finished with error - code:
-1200 /Users/drewloughran/Desktop/SpotBird/SpotbirdparkingTests/SpotbirdparkingTests.swift:117:
error: -[SpotbirdparkingTests.SpotbirdparkingTests test_stripe] :
Asynchronous wait failed: Exceeded timeout of 10 seconds, with
unfulfilled expectations: "Testing stripe returning value".
I am also fairly new to swift so any help would be appreciated with this problem.

Answer 1

Drew, please check this error first. Your request is failing to load.
HTTP load failed (error code: -1200 [3:-9816]) 2019-07-01 09:44:38.189215-0400 Spotbirdparking[49677:4306623] Task .<1> finished with error - code: -1200
Also make sure that the block you are using to fulfill the expectation is being executed. Probably it's not and that's the reason your expectation is not fulfilled and your test is failing.
Also, from this documentation I can see that your validation intersects an automatic validation case. which is redundant.
Response Validation
By default, Alamofire treats any completed request to be successful, regardless of the content of the response. Calling validate before a response handler causes an error to be generated if the response had an unacceptable status code or MIME type.
Manual Validation
Alamofire.request("https://httpbin.org/get")
.validate(statusCode: 200..<300)
.validate(contentType: ["application/json"])
.response { response in
switch response.result {
case .success:
print("Validation Successful")
case .failure(let error):
print(error)
}
}
Automatic Validation
Automatically validates status code within 200...299 range, and that the Content-Type header of the response matches the Accept header of the request, if one is provided.
Alamofire.request("https://httpbin.org/get").validate().responseJSON { response in
switch response.result {
case .success:
print("Validation Successful")
case .failure(let error):
print(error)
}
}
Good luck!

Answer 2

You should not be testing your Alamofire calls by doing actual networking. This causes you to hit the network every time you test; it is unreliable (the network can fail) and unnecessary. We know what the network does! You also do not have to test Alamofire; it isn't yours to test, and again, you know what it does. Therefore you should refactor your code for testing and mock the network call.