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 Sat, 25 Jun 2022 16:43:33 +0000 Sat, 25 Jun 2022 16:43:33 +0000 40 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 We start this series by making a simple GET request to the mock API to fetch the list of episodes. We won't be using a third party library. One of the goals of this series is to show you how to build a modern networking layer that relies on Foundation's URLSession API. It is simpler than you might think. Wed, 20 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-fetching-a-list-of-episodes https://cocoacasts.com/building-a-modern-networking-layer-in-swift-fetching-a-list-of-episodes In this series, you build a modern networking layer for a Swift application using Foundation's URLSession API. We cover a range of topics, basic and more advanced, from making a simple GET request to signing requests with an access token. We make use of generics and protocol-oriented programming to create a networking layer that is flexible, testable, and easy to extend. Mon, 18 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-modern-networking-layer-in-swift-exploring-the-api https://cocoacasts.com/building-a-modern-networking-layer-in-swift-exploring-the-api With the view and the view model in place, we can authenticate the user. In this episode, you learn how to authenticate a user using the URLSession API and basic authentication. Wed, 13 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-sign-in-form-using-swiftui-authenticating-the-user https://cocoacasts.com/building-a-sign-in-form-using-swiftui-authenticating-the-user In the previous episode, we built a sign in form using SwiftUI. In this episode, we create and integrate a view model that drives the sign in form. Tue, 12 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-sign-in-form-using-swiftui-adopting-the-model-view-viewmodel-pattern https://cocoacasts.com/building-a-sign-in-form-using-swiftui-adopting-the-model-view-viewmodel-pattern In this series, we build a sign in form using SwiftUI. In the first episode, we build the user interface. In the next episodes, we apply the model-view-viewmodel pattern and perform a network request to sign the user in. At the end of this series, we have a fully functional sign in form that is ready to be integrated into an application. Mon, 11 Oct 2021 06:30:00 +0000 https://cocoacasts.com/building-a-sign-in-form-using-swiftui-building-the-user-interface https://cocoacasts.com/building-a-sign-in-form-using-swiftui-building-the-user-interface A few years ago, Apple added a number of APIs to the Foundation framework to make it easier to work with units and measurements. The APIs are flexible and straightforward to use. As of this year, SwiftUI integrates with these APIs to make it trivial to display units and measurements. The SwiftUI APIs we discuss in this episode are available as of iOS 15, tvOS 15, macOS 12, and watchOS 8. Wed, 6 Oct 2021 06:30:00 +0000 https://cocoacasts.com/swiftui-essentials-working-with-units-and-measurements-in-swiftui https://cocoacasts.com/swiftui-essentials-working-with-units-and-measurements-in-swiftui To customize a view in a UIKit or AppKit application, you update one or more of the view's properties. For example, to change the text color of a UILabel instance, you update the label's textColor property. That is an imperative approach to user interface development. Wed, 28 Jul 2021 04:30:00 +0000 https://cocoacasts.com/swiftui-fundamentals-customizing-views-with-modifiers https://cocoacasts.com/swiftui-fundamentals-customizing-views-with-modifiers SwiftUI's declarative syntax makes it straightforward to describe the user interface you have in mind. The API is intuitive and the framework's learning curve is gentle. But Apple didn't stop there. SwiftUI is deeply integrated into Xcode, making it almost trivial to build user interfaces using SwiftUI. Wed, 21 Jul 2021 04:30:00 +0000 https://cocoacasts.com/swiftui-fundamentals-working-with-xcode-previews https://cocoacasts.com/swiftui-fundamentals-working-with-xcode-previews A view is the fundamental building block of your application's user interface. You already know that a view is a type that conforms to the View protocol. In this episode, we take a closer look at views and the View protocol. Wed, 14 Jul 2021 04:30:00 +0000 https://cocoacasts.com/swiftui-fundamentals-what-is-a-view https://cocoacasts.com/swiftui-fundamentals-what-is-a-view While it is possible to integrate SwiftUI into a UIKit or AppKit application, this series focuses on building applications that are built entirely using SwiftUI. Wed, 7 Jul 2021 04:30:00 +0000 https://cocoacasts.com/swiftui-fundamentals-exploring-a-swiftui-application https://cocoacasts.com/swiftui-fundamentals-exploring-a-swiftui-application SwiftUI is Apple's brand new framework for building user interfaces for iOS, tvOS, macOS, and watchOS. Apple introduced SwiftUI in 2019 and the framework has been evolving at a rapid pace ever since. Unlike UIKit and AppKit, SwiftUI is a cross-platform framework. With SwiftUI, Apple offers developers a solution for rapidly building applications. In this series, you learn everything you need to build applications using SwiftUI. Wed, 30 Jun 2021 04:30:00 +0000 https://cocoacasts.com/swiftui-fundamentals-what-is-swiftui https://cocoacasts.com/swiftui-fundamentals-what-is-swiftui The API the image service exposes no longer accepts a completion handler. It returns a publisher instead. This is an improvement, but the image service still uses completion handlers under the hood. In this episode, we replace the completion handlers the image service uses internally with publishers. Wed, 23 Jun 2021 04:30:00 +0000 https://cocoacasts.com/building-reactive-applications-with-combine-transforming-publishers-with-flat-map https://cocoacasts.com/building-reactive-applications-with-combine-transforming-publishers-with-flat-map In the previous episode, you learned about futures and promises. In this episode, I show you how to use them in a project. Wed, 16 Jun 2021 04:30:00 +0000 https://cocoacasts.com/building-reactive-applications-with-combine-replacing-completion-handlers-with-futures https://cocoacasts.com/building-reactive-applications-with-combine-replacing-completion-handlers-with-futures Earlier in this series, you learned how a subject can bridge the gap between imperative programming and reactive programming. While subjects are convenient in many ways, they are not always the best option. The Combine framework provides another option. In this episode, we zoom in on futures and promises to bridge the gap between imperative programming and reactive programming. Wed, 9 Jun 2021 04:30:00 +0000 https://cocoacasts.com/building-reactive-applications-with-combine-futures-and-promises https://cocoacasts.com/building-reactive-applications-with-combine-futures-and-promises The first application I published on the App Store was littered with code smells, bad practices, and anti-patterns. The application worked, but it was a challenge to maintain. Adding features to a large, complex project becomes increasingly difficult if it lacks direction and structure. Wed, 2 Jun 2021 04:30:00 +0000 https://cocoacasts.com/five-signs-of-code-smell-in-swift https://cocoacasts.com/five-signs-of-code-smell-in-swift Infinite loops are every developer's nightmare, especially if they have disastrous consequences. You need to be mindful of infinite loops when working with Combine or any other reactive framework. The difficulty is that it isn't always obvious that you created an infinite loop. As a matter of fact, we introduced an infinite loop earlier in this series. You receive a bonus point if you can spot it. Wed, 26 May 2021 04:30:00 +0000 https://cocoacasts.com/building-reactive-applications-with-combine-avoiding-infinite-loops https://cocoacasts.com/building-reactive-applications-with-combine-avoiding-infinite-loops To be productive and efficient, you need to know your tools. For a Swift developer, that means mastering Xcode. While Xcode is a complex piece of software with a fairly steep learning curve, the tricks I show you in this episode should significantly boost your productivity. Wed, 19 May 2021 04:30:00 +0000 https://cocoacasts.com/seven-xcode-tricks-every-developer-should-know https://cocoacasts.com/seven-xcode-tricks-every-developer-should-know