MyRESTClientTests.swift

import XCTest
import Alamofire

class MyRESTClientTests: XCTestCase {

    var client: MyRESTClient?
    var manager: Alamofire.Manager?
    override func setUp() {
        super.setUp()
        // Put setup code here. This method is called before the invocation of each test method in the class.
        let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
        configuration.protocolClasses!.insert(MockingURLProtocol.self, atIndex: 0)
        manager = Manager(configuration: configuration)
    }

    override func tearDown() {
        // Put teardown code here. This method is called after the invocation of each test method in the class.
        client = nil
        super.tearDown()
    }
}

class MockingURLProtocol: NSURLProtocol {

    var cannedResponse: NSData?
    let cannedHeaders = ["Content-Type" : "application/json; charset=utf-8"]

    override func startLoading() {
        let request = self.request
        if request.HTTPMethod == "GET" {
            if request.URL?.absoluteString == "http://notNil/items" {
                cannedResponse = "{\"count\":3,\"items\":[\"car\",\"boat\",\"airplane\"]}".dataUsingEncoding(NSUTF8StringEncoding)
            } else if request.URL?.absoluteString == "http://notRight/items" {
                cannedResponse = "{\"count\":3,\"concepts\":[\"art\",\"beauty\",\"ennui\"]}".dataUsingEncoding(NSUTF8StringEncoding)
            } else {
                cannedResponse = "GARBAGE".dataUsingEncoding(NSUTF8StringEncoding)
            }
            let client = self.client
            let response = NSHTTPURLResponse(URL: request.URL!, statusCode: 200, HTTPVersion: "HTTP/1.1", headerFields: cannedHeaders)
            client?.URLProtocol(self, didReceiveResponse: response!, cacheStoragePolicy: NSURLCacheStoragePolicy.NotAllowed)
            client?.URLProtocol(self, didLoadData: cannedResponse!)
            client?.URLProtocolDidFinishLoading(self)
        }

    }

    override func stopLoading() {
        //noop
    }

    override internal class func canInitWithRequest(request: NSURLRequest) -> Bool {
        return request.URL?.scheme == "http" && (request.HTTPMethod == "GET")
    }

    override internal class func canonicalRequestForRequest(request: NSURLRequest) -> NSURLRequest {
        return request
    }

}