https://cocoacasts.com If you're looking for a quick fix, then I don't have anything to offer you. If you want to become a better Swift developer, then have a seat and let me share with you what I know. en-us Mon, 3 Oct 2022 11:07:36 +0000 Mon, 3 Oct 2022 11:07:36 +0000 40 Enums have a wide range of applications and some of them are not obvious until you learn about them. In this episode of Writing Elegant Code with Enums, you learn how you can use enums to increase type safety and eliminate stringly typed code. Wed, 10 Aug 2022 06:30:00 +0000 https://cocoacasts.com/writing-elegant-code-with-enums-type-safety-with-enums https://cocoacasts.com/writing-elegant-code-with-enums-type-safety-with-enums A magic number is a number that is used in code without much meaning due to the lack of context. Magic numbers are considered an anti-pattern because they make code harder to read, understand, and maintain. Refactoring code that uses magic numbers is also more risky and can be time-consuming. Wed, 3 Aug 2022 06:30:00 +0000 https://cocoacasts.com/code-smells-in-swift-stringly-typed-code https://cocoacasts.com/code-smells-in-swift-stringly-typed-code Remember that a view should be dumb. It doesn't care what it displays. The notes view doesn't match that description. It can access the array of notes through its view model. That is a code smell and something we need to change. You learn how to do that in this episode. Wed, 27 Jul 2022 06:30:00 +0000 https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-hiding-the-model-layer https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-hiding-the-model-layer In the previous episode, we solved some of the problems we discussed earlier in this series. At the same time, we introduced a few code smells. We address those code smells in this episode. Wed, 20 Jul 2022 06:30:00 +0000 https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-fixing-code-smells https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-fixing-code-smells In the previous episode, I highlighted a few problems a typical SwiftUI application can suffer from. These problems can be resolved in several ways. In this series, we explore how the Model-View-ViewModel pattern solves these problems. The goal is to put the views of the application on a diet and decouple view logic from business logic. Wed, 13 Jul 2022 06:30:00 +0000 https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-a-solution https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-a-solution In the previous episode, you learned about the benefits of Swift Concurrency and what problem it solves. Swift Concurrency solves several more problems, which we discuss later in this series. In this episode, we take a peek under the hood to understand how Swift Concurrency does its magic. Wed, 6 Jul 2022 06:30:00 +0000 https://cocoacasts.com/mastering-swift-concurrency-suspending-and-resuming https://cocoacasts.com/mastering-swift-concurrency-suspending-and-resuming With this and the next episode, I want to make sure you choose for the Model-View-ViewModel pattern for the right reasons. I want to avoid that you adopt MVVM in a project because you were told it is a sound architecture or because you think you need view models if you use SwiftUI. In this episode, I want to highlight a few problems a typical SwiftUI application can suffer from. Those problems can be resolved by the Model-View-ViewModel pattern with relative ease. Wed, 29 Jun 2022 06:30:00 +0000 https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-the-problem https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-the-problem You're probably familiar with Swift's nil-coalescing operator. The nil-coalescing operator returns a fallback value if the statement on its left doesn't produce a value. I use it quite often and there is nothing inherently wrong with it. The code smell we discuss in this episode of Code Smells in Swift is the value the statement on the right of the nil-coalescing operator produces, the fallback value. Wed, 22 Jun 2022 06:30:00 +0000 https://cocoacasts.com/code-smells-in-swift-meaningless-fallback-values https://cocoacasts.com/code-smells-in-swift-meaningless-fallback-values The JSONDecoder and JSONEncoder classes make working with JSON a breeze. The true star is Codable, though. Codable, a type alias for Decodable & Encodable, is flexible and provides a lot of functionality for very little effort. From time to time, you run into a situation that makes you scratch your head. This episode covers one such situation. How do you encode null using JSONEncoder? The good news is that the solution is fairly straightforward. Wed, 15 Jun 2022 06:30:00 +0000 https://cocoacasts.com/tips-and-tricks-how-to-encode-null-using-jsonencoder https://cocoacasts.com/tips-and-tricks-how-to-encode-null-using-jsonencoder Before I show you how to adopt Swift Concurrency in a project, I want to take a moment to show you why native support for concurrency was added to the language. Let's take a look at an example to better understand what problem Swift Concurrency solves. Wed, 8 Jun 2022 06:30:00 +0000 https://cocoacasts.com/mastering-swift-concurrency-what-problem-does-swift-concurrency-solve https://cocoacasts.com/mastering-swift-concurrency-what-problem-does-swift-concurrency-solve Before we take a look at Swift Concurrency, it is important that you become familiar with a few core concepts that relate to Swift Concurrency. While you may already be familiar with some of them, this episode should take away any doubt or confusion you have. Wed, 1 Jun 2022 06:30:00 +0000 https://cocoacasts.com/mastering-swift-concurrency-understanding-the-core-concepts https://cocoacasts.com/mastering-swift-concurrency-understanding-the-core-concepts Swift is a type-safe, statically typed language, which means that the compiler checks your code for type errors at compile time. Put simply, you are not able to release your application if your code contains even a single type error. That is a good thing. Wed, 25 May 2022 06:30:00 +0000 https://cocoacasts.com/mastering-unit-testing-in-swift-are-you-writing-unit-tests https://cocoacasts.com/mastering-unit-testing-in-swift-are-you-writing-unit-tests Swift is a type-safe, statically typed language, meaning that each value has a type and the compiler performs type checking at compile time. Your code won't compile if it contains type errors. The benefit is that common bugs are caught early by the compiler. Swift's type system is strict and that also has its drawbacks. It makes the language less dynamic compared to other languages you may be familiar with, such as Ruby and JavaScript. Wed, 18 May 2022 06:30:00 +0000 https://cocoacasts.com/understanding-type-erasure-in-swift-what-is-type-erasure https://cocoacasts.com/understanding-type-erasure-in-swift-what-is-type-erasure If you have been reading or watching Cocoacasts for some time, then you know that the Model-View-ViewModel pattern is one of my preferred patterns for architecting applications. I have been using MVVM for several years in various projects and it continues to prove its value in every project I work on. Wed, 11 May 2022 06:30:00 +0000 https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-views-models-and-view-models https://cocoacasts.com/mastering-model-view-viewmodel-with-swiftui-views-models-and-view-models I love working with enums in Swift. While that may sound odd, I feel enums are undervalued and developers miss out on some of their nicer applications, especially when combined with associated values. Wed, 4 May 2022 06:30:00 +0000 https://cocoacasts.com/writing-elegant-code-with-enums-creating-builders-with-enums https://cocoacasts.com/writing-elegant-code-with-enums-creating-builders-with-enums Types are a fundamental aspect of the Swift language. Swift's type system was pretty easy to understand in the early days. As the language matured, the type system gained in complexity to increase its flexibility. That flexibility came at a cost, though. Today's type system is pretty advanced and some aspects make your head spin. Wed, 27 Apr 2022 06:30:00 +0000 https://cocoacasts.com/mastering-types-in-swift-type-safety-in-swift https://cocoacasts.com/mastering-types-in-swift-type-safety-in-swift In the early days of the Swift language, it took just a few hours to learn the fundamentals of the language. I'm sorry to say that that is no longer true. Swift has become richer and, as a result, more complex. The language has become much more capable, but those capabilities come at a price, increased complexity. Wed, 20 Apr 2022 06:30:00 +0000 https://cocoacasts.com/mastering-swift-concurrency-working-in-a-multithreaded-environment https://cocoacasts.com/mastering-swift-concurrency-working-in-a-multithreaded-environment You learned in the previous episode that it is fine to ignore some of the gaps Xcode finds in your test suite. Even though the goal isn't to fill every gap, we need to write a few more unit tests for the APIClient class. Wed, 13 Apr 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-a-few-more-unit-tests https://cocoacasts.com/building-a-modern-networking-layer-in-swift-a-few-more-unit-tests Unit tests are very useful for testing edge cases. We explored that in the previous episode. Because bugs sometimes hide in edge cases, unit tests can help you track down hard to find bugs. This is only true if the unit tests you write are sound and cover your code. Wed, 6 Apr 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-catching-bugs-with-unit-tests https://cocoacasts.com/building-a-modern-networking-layer-in-swift-catching-bugs-with-unit-tests One of the key benefits of a robust test suite is its ability to quickly and easily test scenarios that are uncommon or hard to reproduce. In this and the next episode, we write unit tests for several scenarios that are difficult to test manually. Manual testing has value, but it is time-consuming and it can be tedious to test edge cases. Wed, 30 Mar 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-unit-tests-for-edge-cases https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-unit-tests-for-edge-cases Step by step we are increasing the code coverage of the APIClient class. In the previous episode, you learned how to use the APIs the APIClient class exposes to unit test its private methods. Remember that the goal isn't to unit test the private methods of the APIClient class. The goal is to increase the code coverage of the APIClient class. We have a few more unit tests to write. Wed, 23 Mar 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-the-wrong-unit-tests https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-the-wrong-unit-tests Code coverage is a very helpful tool to detect gaps in a test suite. In the previous episode, we enabled code coverage to learn how to write better unit tests for the APIClient class. The coverage report shows that the episodes() method is fully covered. It also reveals that the private request(_:) method lacks coverage. Even though the request(_:) method is private to the APIClient class, we can write unit tests to indirectly test it and increase coverage of the APIClient class. That is the focus of this episode. Wed, 16 Mar 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-unit-tests-for-private-methods https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-unit-tests-for-private-methods Are the unit tests we wrote for the /api/v1/episodes endpoint sufficient? How many unit tests should we write? These are some of the questions we answer in this episode. Developers often struggle with unit testing because they aren't sure when enough is enough. As a developer, you want a simple, straightforward answer. The good news is that code coverage can provide that answer. Wed, 9 Mar 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-enabling-code-coverage-to-find-gaps https://cocoacasts.com/building-a-modern-networking-layer-in-swift-enabling-code-coverage-to-find-gaps We can drastically improve the unit tests we wrote in the previous episodes. Even though the unit tests pass without issues, string literals and code duplication are subtle hints that we should take another look at the unit tests we wrote. At the end of this episode, we have a framework in place that we can use for the remaining unit tests of the APIClient class. Wed, 2 Mar 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-readable-and-maintainable-unit-tests https://cocoacasts.com/building-a-modern-networking-layer-in-swift-writing-readable-and-maintainable-unit-tests To create a robust test suite, we need to be in control of the environment the test suite runs in. That includes being in control of the requests the application sends to the Cocoacasts API. We don't want the application to hit the Cocoacasts API when the test suite is run. In this episode, I show you how to stub the Cocoacasts API using the OHHTTPStubs library. Tue, 22 Feb 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-stubbing-the-cocoacasts-api https://cocoacasts.com/building-a-modern-networking-layer-in-swift-stubbing-the-cocoacasts-api Even though the unit test we wrote in the previous episode passes, we quickly discovered that it gives us a false sense of confidence. The unit test passes because it is executed synchronously. To unit test the networking layer, we need to replace the synchronous unit test with an asynchronous unit test. Let me show you how that works. Tue, 15 Feb 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-unit-testing-asynchronous-code https://cocoacasts.com/building-a-modern-networking-layer-in-swift-unit-testing-asynchronous-code The networking layer we are building is nearing completion. We added support for most endpoints of the Cocoacasts API and, later in this series, we add support for refreshing an access token using a refresh token. In the next few episodes, we focus on unit testing the networking layer. Tue, 8 Feb 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-unit-testing-the-networking-layer https://cocoacasts.com/building-a-modern-networking-layer-in-swift-unit-testing-the-networking-layer A build configuration defines the build settings that are used to build the product of a target. As the name suggests, build settings are used to build the product of a target. Even though you don't commonly access build settings in Swift, it can be useful to keep configuration and implementation separate. It is a pattern I have been using for several years. In this episode, I show you how to access build settings in Swift. Tue, 1 Feb 2022 06:30:00 +0000 https://cocoacasts.com/cocoa-fundamentals-how-to-access-builds-settings-in-swift https://cocoacasts.com/cocoa-fundamentals-how-to-access-builds-settings-in-swift The Swift Package Manager has come a long way and support for Xcode improves with every release of Apple's IDE. Even though there are several third party solutions for managing the dependencies of a project, CocoaPods and Carthage being the most popular, the Swift Package Manager has become a viable option in recent years. In this episode, I show you how to add a Swift package to a project in Xcode. Tue, 25 Jan 2022 06:30:00 +0000 https://cocoacasts.com/xcode-fundamentals-how-to-add-a-swift-package-to-a-project https://cocoacasts.com/xcode-fundamentals-how-to-add-a-swift-package-to-a-project In the previous episodes, we added support for fetching, creating, and updating video progress. In this episode, you learn how to delete the progress for a video, the D in CRUD. Deleting the progress for a video is a bit special because the body of the response is empty. Let me show you what changes we need to make to add support for deleting the progress for a video. Tue, 18 Jan 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-deleting-video-progress https://cocoacasts.com/building-a-modern-networking-layer-in-swift-deleting-video-progress In the previous episode, you learned about CRUD operations and we applied this to video progress. We added the ability to fetch the progress for a video, the R in CRUD. In this episode, we cover creating and updating video progress, the C and U in CRUD. Tue, 11 Jan 2022 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-creating-and-updating-video-progress https://cocoacasts.com/building-a-modern-networking-layer-in-swift-creating-and-updating-video-progress At this point, you should have a good understanding of the networking layer we are building. Even though we have written quite a bit of code, the networking layer we built isn't complex. We simply combined a number of common patterns and techniques to create a solution that is easy to use and extend. Later in this series, I show you that it is also easy to test. Tue, 21 Dec 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-fetching-video-progress https://cocoacasts.com/building-a-modern-networking-layer-in-swift-fetching-video-progress The video view model is no longer required to pass an access token to the API client if it requests the video of an episode. That is a welcome improvement. The API client passes an access token to an APIEndpoint object and it is the APIEndpoint object that decides when it is appropriate to add an Authorization header to a request. The changes we made in the previous episode improved the networking layer we are building. Tue, 14 Dec 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-hiding-implementation-details-with-type-erasure https://cocoacasts.com/building-a-modern-networking-layer-in-swift-hiding-implementation-details-with-type-erasure In the previous episode, we extended the API client with the ability to fetch the video for an episode. Because videos are protected resources, the request includes an Authorization header with an access token as its value. The solution we implemented works, but it is tedious to pass the access token to the API client and the object invoking the video(id:accessToken:) method shouldn't need to deal with access tokens. That is a responsibility of the API client. Tue, 7 Dec 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-injecting-the-access-token https://cocoacasts.com/building-a-modern-networking-layer-in-swift-injecting-the-access-token In this and the next episodes, we add the ability for the user to watch an episode. For that to work, the application needs to fetch the video for the episode from the mock API. Fetching a video is similar to fetching the list of episodes. The difference is that the user needs to be signed in to fetch a video because a video is a protected resource. The request to the /videos/:id endpoint needs to include an Authorization header. The value of the Authorization header is the access token the application receives after successfully signing in. Tue, 23 Nov 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-working-with-protected-resources https://cocoacasts.com/building-a-modern-networking-layer-in-swift-working-with-protected-resources Earlier in this series, we declared the computed message property in the APIError enum. While that seemed like a good idea at that time, the previous episode showed that we need a solution that is more flexible. The APIError enum doesn't have the context it needs to define a human-readable message for each of its cases. Tue, 16 Nov 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-better-error-handling https://cocoacasts.com/building-a-modern-networking-layer-in-swift-better-error-handling The user needs to be signed in to watch a video so the next feature we implement is the ability for the user to sign in with their email and password. This episode illustrates how a proper foundation can save time and reduce complexity. The improvements we made in the previous episode simplify the changes we need to make in this and the next episodes. Tue, 9 Nov 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-authenticating-the-user https://cocoacasts.com/building-a-modern-networking-layer-in-swift-authenticating-the-user Because the application will interface with a number of endpoints of the mock API, we need to make sure the API client is easy to extend. The more we can reduce code duplication, the easier it is to extend and maintain the API client. In this episode, I show you how to use generics to make the API client extensible and easy to maintain. Tue, 2 Nov 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-making-the-api-client-extensible https://cocoacasts.com/building-a-modern-networking-layer-in-swift-making-the-api-client-extensible Even though there is nothing inherently wrong with a view model performing network requests, it isn't an approach I recommend. Moving the networking logic out of the view model has a number of benefits. It reduces code duplication, facilitates unit testing, and improves the maintainability of the project to name a few. Mon, 25 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-creating-an-api-client https://cocoacasts.com/building-a-modern-networking-layer-in-swift-creating-an-api-client Handling errors is one of the less enjoyable aspects of software development, but it is an important one. You don't want to show the user a cryptic error message when something goes wrong, or worse, no error message. There is no clear-cut recipe you can follow. Every project is different. The good news is that error handling is built into Swift and the Combine framework. Let me show you how we can improve the code we wrote in the previous episode. Fri, 22 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-handling-errors https://cocoacasts.com/building-a-modern-networking-layer-in-swift-handling-errors