🔒 We have now totally reimagined the design of our case paths library to create actual key paths

for enum cases, but there is some boilerplate involved. Let’s create a macro that eliminates

all of it and explore a few of the possibilities it unlocks.

🔒 “Case paths” grant key path-like functionality to enum cases. They solve many problems in

navigation, parsing, and architecture, but fall short of native key paths…till now. Let’s

close this gap using macros that generate actual key paths to enum cases.

🔒 We take all we've learned about the Observation framework and apply it to a larger, more real

world application: our rewrite of Apple's Scrumdinger demo. We'll see what changes are easy to

make, what changes are a bit trickier, and encounter a bug that you'll want to know about.

🔒 We've explored the present state of observation in Swift, so what's the future have in store? Currently, observation is restricted to classes, while one of Swift's most celebrated features, value types, is left out in the cold. Let's explore a future in which observation is extended to value types.

🔒 While the `@Observable` macro improves upon nearly every aspect of the `@State` and `@ObservedObject` property wrappers, it is not without its pitfalls. We will explore several gotchas that you should be aware of when adopting observation in your applications.

🔒 The `@Observable` macro is here and we will see how it improves on nearly every aspect of the old tools in SwiftUI. We will also take a peek behind the curtain to not only get comfortable with the code the macro expands to, but also the actual open source code that powers the framework.

🔒 It's time to dive deep into Swift's new observation tools. But to start we will take a look at the tools SwiftUI historically provided, including the `@State` and `@ObservedObject` property wrappers, how they behave and where they fall short, so that we can compare them to the new `@Observable` macro.

🆓 Let's take our MacroTesting library for a spin with some more advanced macros, including those

that Apple has gathered since the feature's introduction, as well as a well-tested library in

the community: Ian Keen's MacroKit.

🆓 Macros are here! To celebrate, we are releasing a brand new tool to aid in writing tests for them. First, let's explore testing macros using the tools that Apple provides, evaluate their shortcomings, and see how we can address them.

🔒 We conclude the series by adding the final bit of functionality to our application: persistence. We'll see how adding a dependency on persistence can wreak havoc on previews and tests, and all the benefits of controlling it.