How do I move my project to Swift 6?

To move your project to Swift 6, you can follow a structured process as outlined in the WWDC sessions. Here are the key steps:

1. Enable Complete Concurrency Checking:

   • This is a per-module setting that leaves your project in Swift 5 mode but enables warnings for all the code that would fail with Swift 6's enforced data isolation.
   • Go through and resolve all these warnings for each target in your project.

2. Enable Swift 6 Mode:

   • Once you have resolved the warnings for a target, enable Swift 6 mode for that target. This locks in all your changes and prevents any future refactorings from regressing to an unsafe state.
   • Repeat this process for each target in your project.

3. Incremental Migration:

   • You can migrate to Swift 6 incrementally, one module at a time. This means you don't need to wait for all your dependencies to migrate before you start.
   • When your dependencies do migrate, you don't need to make any changes to your code until you decide to use the new language mode.

4. Compiler Diagnostics:

   • The new Swift 6 compiler diagnostics will guide you towards the places in your code that need fixing, acting like a pair programmer pointing out potential bugs.

5. Adopt Concurrency Features:

   • Swift 6 introduces full data isolation enforcement, which helps catch mistakes in concurrent code at compile time. This is especially useful for eliminating hard-to-reproduce crashes and ensuring that new concurrency changes don't introduce data races.

6. Follow the Migration Guide:

   • Swift.org provides a migration guide with insights and patterns on how best to modify your code to eliminate data races.

For a detailed walkthrough, you can refer to the session Migrate your app to Swift 6 (06:20).

Relevant Sessions

• What’s new in Swift
• Migrate your app to Swift 6
• Platforms State of the Union

These sessions provide comprehensive guidance on the new features in Swift 6 and the migration process.