Unit test :- Prepare URLRequest -> Parse Response, Integration test:- Prepare URLRequest -> Create URLSession Task -> Parse Response

UnitTesting.playground

//Unit test :- Prepare URLRequest -> Parse Response
class PointOfInterestRequestTests: XCTestCase {
    let request = PointsOfInterestRequest()
    func testMakingURLRequest() throws {
        let coordinate = CLLocationCoordinate2D(latitude: 37.3293, longitude: -121.8893)
        let urlRequest = try request.makeRequest(from: coordinate)
        
        XCTAssertEqual(urlRequest.url?.scheme, "https")
        XCTAssertEqual(urlRequest.url?.host, "example.com")
        XCTAssertEqual(urlRequest.url?.query, "lat=37.3293&long=-121.8893")
    }
    func testParsingResponse() throws {
        let jsonData = "[{\"name\":\"My Location\"}]".data(using: .utf8)!
        let response = try request.parseResponse(data: jsonData)
        
        XCTAssertEqual(response, [PointOfInterest(name: "My Location")])
    }
    
    
}
PointOfInterestRequestTests.defaultTestSuite.run()

//Integration test:- Prepare URLRequest -> Create URLSession Task -> Parse Response
class APILoaderTests: XCTestCase {
    var loader: APIRequestLoader<PointsOfInterestRequest>!
    override func setUp() {
        let request = PointsOfInterestRequest()
        let configuration = URLSessionConfiguration.ephemeral
        configuration.protocolClasses = [MockURLProtocol.self]
        let urlSession = URLSession(configuration: configuration)
        loader = APIRequestLoader(apiRequest: request, urlSession: urlSession)
    }
    func testLoaderSuccess() {
        let inputCoordinate = CLLocationCoordinate2D(latitude: 37.3293, longitude: -121.8893)
        let mockJSONData = "[{\"name\":\"MyPointOfInterest\"}]".data(using: .utf8)!
        MockURLProtocol.requestHandler = { request in
            XCTAssertEqual(request.url?.query?.contains("lat=37.3293"), true)
            return (HTTPURLResponse(), mockJSONData)
        }
        let expectation = XCTestExpectation(description: "response")
        loader.loadAPIRequest(requestData: inputCoordinate) { pointsOfInterest, error in
            XCTAssertEqual(pointsOfInterest, [PointOfInterest(name: "MyPointOfInterest")])
            expectation.fulfill()
        }
        wait(for: [expectation], timeout: 1)
    }
}
APILoaderTests.defaultTestSuite.run()