Test-Driven Development in Swift: Compile Better Code with XCTest and TDD

Cheatsheet

XCTest Test Structure

Create a test case by subclassing XCTestCase and define tests as methods with the test prefix. A good structure for your test is to separate it into three stages: Arrange, Act, and Assert:

@testable import MyApp

import XCTest

class UserTests: XCTestCase {

    func testFullNameMergesFirstAndLastNames() {

        // Arrange the system under test and its inputs

        let user = User(firstName: "Grace", lastName: "Hopper")

        // Act on the SUT to generate the output

        let fullName = user.fullName

        // Assert the output matches the expected result

        XCTAssertEqual(fullName, "Grace Hopper")

    }

}

See Chapter 2 for more details.

How to Test Asynchronous Code

To test callback-based asynchronous behavior, ...