3. Wiring with Design

Coming soon

This chapter is an outline. The full draft ships in a follow-up PR.

What this chapter will cover

Part III goes back to the Design.build shape you already met in Parts I and II, and explains it properly. By the end of it you should be able to look at an unfamiliar Design.newDesign... block and know exactly what it is saying.

Concepts introduced:

• Why constructor injection is preferred over globals, service locators, and runtime reflection.
• bindSingleton, bindImpl, bindInstance, bindProvider — which to reach for, and why.
• design.build[A] { ... } as the convenience entry point, and withSession underneath it for cases where you need access to the session itself.
• Sessions, child sessions, and scoping: when one instance lives for the whole process vs. per-request.
• Lifecycle hooks (onStart, onShutdown) and how they compose with sessions.
• Overriding a design for tests (the foundation for Chapter 12).
• Common mistakes and how to read the error messages Design produces.

Reference you can read now

While this chapter is in progress, the reference page is complete:

• Design (module reference)

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