MockURL

Countries-MockURL.swift

import Foundation



class MockURL: URLProtocol {
    static var requestHandler: ((URLRequest) throws -> (HTTPURLResponse, Data?))?
    
    override class func canInit(with request: URLRequest) -> Bool {
      // To check if this protocol can handle the given request.
      return true
    }

    override class func canonicalRequest(for request: URLRequest) -> URLRequest {
      // Here you return the canonical version of the request but most of the time you pass the orignal one.
      return request
    }

    override func startLoading() {
     
        guard let handler = MockURLProtocol.requestHandler else {
           fatalError("Handler is unavailable.")
         }
           
         do {
           // 2. Call handler with received request and capture the tuple of response and data.
           let (response, data) = try handler(request)
           
           // 3. Send received response to the client.
           client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: .notAllowed)
           
           if let data = data {
             // 4. Send received data to the client.
             client?.urlProtocol(self, didLoad: data)
           }
           
           // 5. Notify request has been finished.
           client?.urlProtocolDidFinishLoading(self)
         } catch {
           // 6. Notify received error.
           client?.urlProtocol(self, didFailWithError: error)
         }
        
        
    }

    override func stopLoading() {
      // This is called if the request gets canceled or completed.
    }
}