Swift

What’s the difference? XCTest doesn’t provide a built-in solution for parameterized tests. To achieve this, we create test cases as structs or tuples, defining test inputs and expected results. Then, we write a loop to iterate through these test cases and execute the necessary assertions. Swift Testing simplifies this process by allowing tests to be parameterized directly. Using the @Test macro, you can pass test cases as an argument. What’s the benefit? While you still need to define your test cases, the iteration code is no longer needed — Swift Testing handles it for you. ...

Swift code refactor in action 👨🏻‍💻 Today, let’s talk about refactoring for clarity, maintainability, and scalability! This time, the scenario is calculating the final price depending on the price and membership status. This initial code has a few code smells: 1️⃣ nested ifs - impacts general readability, making the code hard to understand, 2️⃣ duplicated conditions - “price > 100” which violates the Don’t Repeat Yourself principle, 3️⃣ lack of scalability - not possible to easily add a new discount, it’d require to rework everything. Checkout the gif or the post on my website to see how I solve these code smells and make the code cool, clean and scalable! ...

Today we check the diff in conditional disabling. In XCTest there is XCTSkipIf function that takes Bool argument to decide whether a test should run or not. In Swift Testing there’s “disable” trait accepting Bool argument and behaving like XCTSkipIf from XCTest. XCTSkipIf - are you surprised this kind of function exists? To be honest - I was I can admit I learned about it when preparing this post. This already shows how often I’ll be using the Swift Testing version of it, but never say never! ...

This week with Swift Testing starts with checking how test disabling differs from XCTest. In XCTest, Xcode identifies a function as a test only if its name starts with the “test” prefix, so putting e.g. “disabled” instead makes the test inactive. Swift Testing simplifies that approach by introducing the @Test macro with a .disabled trait that you can pass as an argument. What’s the benefit? You no longer need to modify each test name to disable it. What’s more, you can include context directly within the trait to justify why the test is disabled. ...

What is macro? 💡 Macro is a feature that generates code during compilation. Unlike macros in C, which work like “find and replace”, Swift macros are type-safe and context aware, making them powerful tools reducing boilerplate code. Two types of macros attached - use @ prefix, tied to a declaration adding extra logic to it, like: @Test, @Model, @Observable freestanding - use # prefix, standalone code that can be invoked independently as a part of the code, like #expect, #Predicate, #warning Example of attached macro ⤵️ ...