Sampling Codebase Patterns in Hanami 2.x

This document guides developers and agents on how to identify, inspect, and match existing design patterns within a Hanami codebase.

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What to Sample

To maintain codebase architectural consistency, analyze files from three main layers:

1. Action Patterns

When sampling files in app/actions/ or slices/*/actions/, identify:

• Base class: What action class do they inherit from (e.g. MyApp::Action, Admin::Action)?
• DI usage: How are dependencies declared (e.g. include Deps["repos.user_repo"])?
• Response handling: Are they rendering views, returning JSON strings directly, or using halt?
• Params validation: Is there an inline params schema block or do they delegate validation?

2. Operation Patterns

When sampling files in app/operations/ or slices/*/operations/, identify:

• Monadic Results: Do they return Success/Failure using dry-monads?
• Do Notation: Is include Dry::Monads::Do.for(:call) used to chain commands?
• Interface: Is #call the universal execution entry point?

3. Repository/Database Patterns

When sampling files in app/repos/ or slices/*/repos/, identify:

• Inheritance: Do they inherit from a central base repository (e.g. Hanami::DB::Repo[:users])?
• Namespace mapping: Is struct_namespace configured to map database results to domain entities?
• Scope usage: Do they call relation scopes or execute custom queries inside repo methods?