Mockingjay 3.0.0-alpha.1

Mockingjay 3.0.0-alpha.1

LangLanguage SwiftSwift
License BSD-3-Clause
ReleasedLast Release Jun 2019
SPMSupports SPM

Maintained by Kyle Fuller.

Mockingjay 3.0.0-alpha.1


An elegant library for stubbing HTTP requests in Swift, allowing you to stub any HTTP/HTTPS using NSURLConnection or NSURLSession. That includes any request made from libraries such as Alamofire and AFNetworking.


CocoaPods is the recommended installation method.

pod 'Mockingjay'


Mockingjay has full integration to XCTest and you simply just need to register a stub, it will automatically be unloaded at the end of your test case. It will also work with the Quick behaviour-driven development framework.

Simple stub using a URI Template, returning a response with the given JSON encoded structure

let body = [ "user": "Kyle" ]
stub(uri("/{user}/{repository}"), json(body))

The uri function takes a URL or path which can have a URI Template. Such as the following:

  • /kylef/{repository}
  • /kylef/URITemplate.swift

Stubbing a specific HTTP method with a JSON structure

let body = [ "description": "Kyle" ]
stub(http(.put, uri: "/kylef/Mockingjay"), json(body))

Stubbing everything request to result in an error

let error = NSError()
stub(everything, failure(error))

Stub with a specific HTTP response

stub(everything, http(status: 404))

Note, the http builder can take a set of headers and a body too.


The stub method in Mockingjay takes two functions or closures, one to match the request and another to build the response. This allows you to easily extend the syntax to provide your own specific functions.

stub(matcher, builder)


A matcher is simply a function that takes a request and returns a boolean value for if the stub matches the request.

func matcher(request:URLRequest) -> Bool {
  return true  // Let's match this request

stub(matcher, failure(error))


Builders are very similar to a matcher, it takes a request, and it returns either a success or failure response.

func builder(request: URLRequest) -> Response {
  let response = HTTPURLResponse(url: request.url!, statusCode: 200, httpVersion: nil, headerFields: nil)!
  return .success(response, .noContent)

stub(matcher, builder)


You can make use of the builtin generic matchers and builders. These can be used alone, or in conjunction with custom components.

Builtin Matchers

  • everything - Matches every given request.
  • uri(template) - Matches using a URI Template.
  • http(method, template) - Matches using a HTTP Method and URI Template.

Builtin Builders

  • failure(error) - Builds a response using the given error.
  • http(status, headers, data) - Constructs a HTTP response using the given status, headers and data.
  • json(body, status, headers) - Constructs a JSON HTTP response after serialising the given body as JSON data.
  • jsonData(data, status, headers) - Constructs a JSON HTTP response with raw JSON data.

Using JSON files as test fixtures

During setUp, load the JSON file as NSData and use jsonData.

override func setUp() {
  let url = Bundle(for: type(of: self)).url(forResource: "fixture", withExtension: "json")!
  let data = try! Data(contentsOf: url)
  stub(matcher, jsonData(data))


Mockingjay is licensed under the BSD license. See LICENSE for more info.