driesschulten / rxexpect

The RxSwift testing framework

RxExpect

RxExpect is a testing framework for RxSwift.

Concept

Provide inputs then test outputs. This is an example code that tests map() operator multiplying the values by 2.

func testMultiply() {
  RxExpect("it should multiply values by 2") { test in
    let value = PublishSubject<Int>()
    let result = value.map { $0 * 2 }

    // provide inputs
    test.input(value, [
      next(100, 1),
      next(200, 2),
      next(300, 3),
      completed(400)
    ])
    
    // test output
    test.assert(result)
      .equal([
        next(2),
        next(4),
        next(6),
        completed(400)
      ])
  }
}

It would be easy to understand if you imagine the marble diagram.

time   --100-200-300-400 // virtual timeline
value  --1---2---3---|   // provide inputs
result --2---4---6---|   // test these values

This is more complicated example.

final class ArticleDetailViewModelTests: RxTestCase {

  func testLikeButtonSelected() {
    RxExpect("like button should become selected when like button tapped") { test in
      let viewModel = ArticleDetailViewModel()

      // providing an user input: user tapped like button
      test.input(viewModel.likeButtonDidTap, [
        next(100),
      ])

      // test output: like button become selected
      test.assert(viewModel.isLikeButtonSelected)
        .filterNext()
        .since(100)
        .equal([true])
    }
    
    RxExpect("like button should become unselected when like button tapped") { test in
      let viewModel = ArticleDetailViewModel()

      // providing an user input: user tapped like button
      test.input(viewModel.likeButtonDidTap, [
        next(100),
      ])

      // test output: like button become selected
      test.assert(viewModel.isLikeButtonSelected)
        .filterNext()
        .since(100)
        .equal([false])
    }
  }

}

Examples

• RxTodo

APIs

Providing Inputs

• input(observer, events)
• input(variable, events)

Start Assertion Chaining

• assert(source)

Filtering Events

• filterNext()
• since(timeSince)
• until(timeUntil)
• within(timeRange)

Reversing Result

• not()

Assertions

• equal(expectedEvents)
• isEmpty()
• contains()

Installation

• For iOS 8+ projects with CocoaPods:

  pod 'RxExpect', '~> 0.5'

• For iOS 8+ projects with Carthage:

  github "devxoul/RxExpect" ~> 0.5
  

Development

$ git clone https://github.com/devxoul/RxExpect
$ cd RxExpect
$ carthage checkout --no-use-binaries
$ open RxExpect.xcworkspace

License

RxExpect is under MIT license. See the LICENSE file for more info.