packtpublishing/package-swift-cleanup

Skill: Package.swift Structural Cleanup

Context

This project uses Package.swift files not only as dependency manifests, but as architectural artifacts.

Package files encode:

• feature-based modularization,
• dependency classification (external, utility, abstraction),
• and architectural intent through enums and helper extensions.

This structure is not standard Swift Package Manager usage and must be handled explicitly.

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1. Domain-Scoped Data Modules

Modules such as BasketData, ProductData, and UserData belong to the Data layer. They provide infrastructure implementations (repositories, services, data sources) scoped by domain.

Rules:

• Each enum case represents an active Data-layer module.
• Modules are organized by business domain, not by UI feature.
• Targets and test targets are generated from enum cases.
• Do not inline targets manually.

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2. Dependency Classification

Dependencies are classified using enums:

• ExternalModule → third-party libraries (e.g. RxSwift)
• Utility → cross-cutting technical packages (e.g. Networking / API)
• AbstractionModule → domain-facing contracts (interfaces)

These enums are semantic, not incidental.

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3. Cleanup Rules

When a dependency is removed from the codebase:

Required actions:

• Remove the package from Package.dependencies
• Remove all target-level references
• Remove unused enum cases in dependency classification enums
• Remove entire enums if they become empty
• Remove helper extensions that exist only for removed dependencies

Forbidden actions:

• Do not comment out obsolete dependencies
• Do not keep unused enum cases as placeholders
• Do not preserve architectural constructs that no longer reflect reality

Package.swift must describe the current architecture, not its history.

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4. Obsolete Dependency Cleanup Rule

Any dependency classification entry (external, abstraction, or utility) that is no longer referenced by any target must be removed.

This includes:

• enum cases that are no longer used,
• entire enums that become empty after cleanup,
• helper extensions that only exist to support removed dependencies.

Leaving unused architectural constructs in Package.swift is considered a structural error.

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5. Consistency Across Packages

This cleanup must be applied consistently:

• across all feature packages,
• across Data, Domain, Utilities, etc.

Partial cleanup is not acceptable.

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Validation Checklist

Before considering Package.swift cleanup complete:

• [ ] No unused enums remain
• [ ] No unused dependency helpers remain
• [ ] Dependency graph reflects actual code usage
• [ ] Package.swift still compiles
• [ ] Architectural intent remains readable

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Goal

The goal of this Skill is to ensure that Package.swift remains:

• truthful to the codebase,
• expressive of architecture,
• free of obsolete concepts after refactoring.

This Skill prioritizes semantic clarity over mechanical cleanup.