Sleipnir BDD style testing for Swift

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Outline What is BDD Testing in Swift - XCTest vs BDD style What Sleipnir is How to use it Questions

BDD

BDD Behavior Driven Development

BDD Behavior Driven Development BDD species that tests of any unit of software should be specied in terms of the desired behaviour of the unit. (from Wiki) ! BDD is all about specications

BDD describe("Calculator") { ! describe("#add") { ! it("returns the sum of its arguments") { expect(Calculator().add(1, 2)).to(equal(3)) } } }

Testing in Swift

Testing in Swift - XCTest class BookTest : XCTestCase { func testPersonHasName() { let person = Person(name: "John Doe) ! XCTAssertNotNil(person.name, "name should not be nil") XCTAssertEqual(person.name, "John Doe", "incorrect name") } }

Testing in Swift - XCTest class BookTest : XCTestCase { func testPersonHasName() { let person = Person(name: "John Doe) ! XCTAssertNotNil(person.name, "name should not be nil") XCTAssertEqual(person.name, "John Doe", "incorrect name") } } Does not specify behavior of the `Person` class

Testing in Swift - BDD class PersonSpec : SleipnirSpec { var personSpec = describe("Person") { let person = Person(name: "John Doe") context("name") { it("should not be nil") { expect(person.name).toNot(beNil()) } it("should be correct") { expect(person.name).to(equal("John Doe")) } } } }

Testing in Swift - BDD Test code is a specication of a class: Person name should not be nil Person name should be correct

Introducing Sleipnir https://github.com/railsware/Sleipnir

What Sleipnir is Mythological steed of Odin, Norse God

What Sleipnir is BDD-style framework for Swift

What Sleipnir is class HorseSpec : SleipnirSpec { var spec = describe("Horse") { context("usual") { it("is not awesome") { let usualHorse = UsualHorse() expect(usualHorse.legsCount).to(equal(4)) usualHorse.isAwesome.should.beFalse() } } context("Sleipnir") { it("is awesome") { let sleipnirHorse = Sleipnir() expect(sleipnirHorse.legsCount).to(equal(8)) sleipnirHorse.isAwesome.should.beTrue() } } } }

Core principles Not using XCTest Pure Swift BDD testing framework Command line output Seeded random tests invocation

How to use it

Running specs 1. Create a test target in Xcode 2. Invoke Runner.run() method in main.swift 3. Run test target

Running specs Running With Random Seed: 7197 ! ...F...... ! ! FAILURE Some spec should pass: /Path/To/Your/Specs/SomeSpec.swift:27 Expected to equal ! ! Finished in 0.0102 seconds ! 10 examples, 1 failures

Setup/Teardown blocks beforeEach { } afterEach { } beforeAll { } afterAll { }

Setup/Teardown blocks let someSpec = describe("Some spec") { var someArray: [Int]? ! beforeEach { someArray = [1, 2, 3] } afterEach { someArray = nil } it("should pass") { expect(someArray).toNot(beNil()) expect(someArray).to(contain(3)) } }

Focused specs Focus means Run only focused stuff Useful in a project with a lot of specs

Focused specs describe("Some spec") { fit("focused") { // WILL RUN } it("not focused") { // WILL NOT RUN } }

Focused specs fdescribe("focused group") { // ... } ! fcontext("focused group") { // ... } fit("focused example") { // ... }

Pending specs Pending means Dont run this stuff Useful to denote an example that does not pass yet

Pending specs xdescribe("Pending group") { it("will not run") { expect(false).to(beTrue()) } it("is pending", PENDING) } Running With Random Seed: 2428 ! ...P....... ! PENDING Pending group is pending ! ! Finished in 0.0062 seconds ! 11 examples, 0 failures, 1 pending

Shared example groups Useful for extracting common specs Allow to run same specs in different context

Shared example groups sharedExamplesFor("some awesome stuff") { (sharedContext : SharedContext) in var stuff: Stuff? beforeEach { stuff = sharedContext()["stuff"] as Stuff } it("should be awesome") { expect(stuff.awesome).to(beTrue()) } }

Matchers equal beNil beFalse/beTrue beGreaterThan/beLessThan expect(3).to(equal(3)) expect(3).toNot(beNil()) expect(true).to(beTrue()) expect(3).to(beGreaterThan(1))

Matchers on collections/strings contain beginWith/endWith beEmpty expect([1,2,3]).to(contain(1,2)) expect("foobar").to(beginWith("foo")) expect([1,2,3]).toNot(beEmpty())

Questions? https://github.com/railsware/Sleipnir