Quick – Waiting for Alamofire in unit test

import Alamofire
import RealmSwift
import SwiftyJSON

class Thingy: Object {

 // some properties 
 dynamic var property

 // refresh instance
 func refreshThingy() {
 Alamofire.request(.GET, URL)
 .responseJSON {
 response in
 self.property = response["JSON"].string
 }
 }
}

import Alamofire
import SwiftyJSON
import XCTest
@testable import MyModule
< br />class Thingy_Tests: XCTestCase {

func testRefreshThingy() {
 let testThingy: Thingy = Thingy.init()
 testThingy.refreshProject()
 XCTAssertEqual( testThingy.property, expected property)
}

func testExample() {
 let e = expectation(description: "Alamofire")

 Alamofire.request(urlString)
 .response {response in
 XCTAssertNil(response.error, "Whoops, error \(response.error!.localizedDescription)")

 XCTAssertNotNil(response, "No response")
 XCTAssertEqual(response.response? .statusCode ?? 0, 200, "Status code not 200")

 e.fulfill()
 }

 waitForExpectations(timeout: 5.0, handler: nil )
}

class Thingy {

 var property: String!

 func refreshThingy(completionHandler: ((String?) -> Void)?) {
 Alamofire.request(someURL) 
 .responseJSON {response in
 if let json = response.result.val ue as? [String: String] {
 completionHandler?(json["JSON"])
} else {
 completionHandler?(nil)
 }
 }< br /> }
}

func testThingy() {
 let e = expectation( description: "Thingy")

 let thingy = Thingy()
 thingy.refreshThingy {string in
 XCTAssertNotNil(string, "Expected non-nil string")
 e.fulfill()
 }

 waitForExpectations(timeout: 5.0, handler: nil)
}

I am trying to write a method where the data object (Realm) uses Alamofire to refresh its properties. But I can’t figure out how to unit test it.

import Alamofire
import RealmSwift
import SwiftyJSON

class Thingy: Object {

 // some properties
 dynamic var property

 // refresh instance
 func refreshThingy() {
 Alamofire.request(.GET, URL)
 .responseJSON {
 response in
 self.property = response["JSON"].string
 }
 }
}

In my unit test, I want to test whether Thingy can refresh the server normally.

import Alamofire
import SwiftyJSON
import XCTest
@testable import MyModule

class Thingy_Tests: XCTestCase {

func testRefreshThingy() {
 let testThingy : Thingy = Thingy.init()
 testThingy.refreshProject()
 XCTAssertEqual(testThingy.property, expected property)
}

How to properly set up unit tests for this?

Use XCTestExpectation to wait for an asynchronous process, for example:

func testExample() {
 let e = expectation(description: "Alamofire")

 Alamofire.request(urlString)
 .response {response in
 XCTAssertNil(response.error, "Whoops, error \(response.error!.localizedDescription)")

 XCTAssertNotNil(response, "No response")
 XCTAssertEqual(response.response?.statusCode ?? 0, 200, "Status code not 200")

 e.fulfill()
 }

 waitForExpectations(timeout: 5.0, handler: nil)
}

In your case, if you want to test an asynchronous method, you must provide a completion handler for refreshThingy:

class Thingy {

 var property : String!

 func refreshThingy(completionHandler: ((String?) -> Void)?) {
 Alamofire.request(someURL)
 .responseJSON {response in
 if let json = response.result.value as? [String: String] {
 compl etionHandler?(json["JSON"])
} else {
 completionHandler?(nil)
 }
 }
 }
}

Then you can test Thingy:

func testThingy() {
 let e = expectation(description: "Thingy")

 let thingy = Thingy()
 thingy.refreshThingy {string in
 XCTAssertNotNil(string, "Expected non-nil string")
 e.fulfill()
 }

 waitForExpectations(timeout: 5.0, handler: nil)
}

Frankly, anyway, this mode of using completion handlers may be what you want in refreshThingy The mode used, but if you may not want to provide a completion handler, I will make it optional.