Xcode: URL Shared Session not running when unit testing - ios

Question

I have made a simple app which adds data to a database, and then retrieves it. Whilst creating unit testing, it appears that the URLSession.Shared.dataTask is not running. I can see this through the output of the print statements I have setup. Below is my code:
func addChild(childName:String,dob:String,number1:String,number2:String,parentNum:String,parentPass:String,notes:String){
//url to php file
let url = NSURL(string:"http://localhost/addChild.php")
//request to this file
let request = NSMutableURLRequest(url: url as! URL)
//method to pass data to this file
request.httpMethod = "POST"
//body to be appended to url
let body = "childName=\(childName)&dateOfBirth=\(dob)&contact1=\(number1)&contact2=\(number2)&parentAccNum=\(parentNum)&parentAccPass=\(parentPass)&notes=\(notes)"
request.httpBody = body.data(using: String.Encoding.utf8)
print("a")
//launching the request
URLSession.shared.dataTask(with: request as URLRequest, completionHandler: { (data:Data?, response:URLResponse?, error:Error?) in
print("b")
if (error == nil){
print("c")
//send request
//get main queue in code process to communicate back to user interface
DispatchQueue.main.async(execute: {
do{
//get json result
let json = try JSONSerialization.jsonObject(with: data!,options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary
print("d")
//assigning json to parseJSON in guard/secure way
//checking whether the parsing has worked
guard let parseJSON = json else{
print("Error while parsing")
return
}
//get id from parseJSON dictionary
let id = parseJSON["id"]
//if there is some id value
if id != nil{
print(parseJSON)
self.success = true
print("success")
}
}
catch{
print("Caught an error:\(error)")
}
} )
}
//if unable to proceed request
else{
print("Error:\(error)")
}
//launch prepared session
}).resume()
}
And then below is my unit testing script:
import XCTest
#testable import computerScienceCoursework
class addChildTest: XCTestCase {
//Setting up the values of the text fields
var testChildName:String = "Test name"
var testDOB:String = "99/99/99"
var testContact1:String = "00000000000"
var testContact2:String = "11111111111"
var testParAccNum:String = "-1"
var testParAccPass:String = "Password"
var testNotes:String = "Insert notes here"
var newChild = AddChildController()
override func setUp() {
super.setUp()
// Put setup code here. This method is called before the invocation of each test method in the class.
}
override func tearDown() {
// Put teardown code here. This method is called after the invocation of each test method in the class.
super.tearDown()
}
func testAddChildIsWorking(){
//Assigning the values to the text fields
newChild.addChild(childName: testChildName,dob: testDOB,number1: testContact1,number2: testContact2,parentNum: testParAccNum,parentPass: testParAccPass,notes: testNotes)
XCTAssert(newChild.success == true)
}
}

Answer 1

Problem here is that you don´t know when the async task is finished and the success property is getting updated.
There are some possible solutions for your problem one of them is to add a completion handler to your method.
func addChild(childName:String,dob:String,number1:String,number2:String,parentNum:String,parentPass:String,notes:String, completion: (Bool) -> Void){
//url to php file
let url = NSURL(string:"http://localhost/addChild.php")
//request to this file
let request = NSMutableURLRequest(url: url as! URL)
//method to pass data to this file
request.httpMethod = "POST"
//body to be appended to url
let body = "childName=\(childName)&dateOfBirth=\(dob)&contact1=\(number1)&contact2=\(number2)&parentAccNum=\(parentNum)&parentAccPass=\(parentPass)&notes=\(notes)"
request.httpBody = body.data(using: String.Encoding.utf8)
print("a")
//launching the request
URLSession.shared.dataTask(with: request as URLRequest, completionHandler: { (data:Data?, response:URLResponse?, error:Error?) in
print("b")
if (error == nil){
print("c")
//send request
//get main queue in code process to communicate back to user interface
DispatchQueue.main.async(execute: {
do{
//get json result
let json = try JSONSerialization.jsonObject(with: data!,options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary
print("d")
//assigning json to parseJSON in guard/secure way
//checking whether the parsing has worked
guard let parseJSON = json else{
print("Error while parsing")
completion(false)
return
}
//get id from parseJSON dictionary
let id = parseJSON["id"]
//if there is some id value
if id != nil{
print(parseJSON)
self.success = true
print("success")
completion(true)
}
}
catch{
print("Caught an error:\(error)")
completion(false)
}
} )
}
//if unable to proceed request
else{
print("Error:\(error)")
completion(false)
}
//launch prepared session
}).resume()
}
Then in your test method you can the method.
func testAddChildIsWorking()
{
let asyncExpectation = expectationWithDescription("addChildIsWorkingFunction")
newChild.addChild(childName: testChildName, dob: testDOB, number1: testContact1,
number2: testContact2, parentNum: testParAccNum, parentPass: testParAccPass, notes: testNotes) { (success) in
asyncExpectation.fulfill()
}
self.waitForExpectationsWithTimeout(10) { error in
XCTAssert(newChild.success == true)
}
}
waitForExpectationWithTimeout is waiting until a fulfill is trigger or a timeout occurs. In this way you could test your async code.
For more informations check this link
Hope that helps.