domain-logic-module

Name: domain-logic-module
Availability: InStock
Author: velcrafting

Encapsulate domain rules into a testable module boundary with preconditions and postconditions.

1|Updated Jan 13, 2026

Search Tags:#backend #refactor #module #invariants #domain #unit-tests

Ready to run

npx skills add https://github.com/velcrafting/codex-skills --skill domain-logic-module

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: domain-logic-module
Source: https://github.com/velcrafting/codex-skills/tree/main/skills/backend/domain-logic-module
Command: npx skills add https://github.com/velcrafting/codex-skills --skill domain-logic-module

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Consolidate domain rules into a dedicated, testable module boundary to prevent invariants from leaking into controllers, jobs, or adapters.

Core Features & Use Cases

Encapsulated domain invariants with a clear API surface.
Unit-testable module boundaries that enforce rules across boundaries.
Supports scalable refactoring of business logic while maintaining deterministic errors.

Quick Start

Refactor domain rules into a testable module boundary and add unit tests to cover invariants.

Frequently Asked Questions about domain-logic-module

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I isolate domain logic and invariants from controllers and adapters?▼

To isolate domain logic, you encapsulate domain rules and invariants into a dedicated, testable module boundary, preventing them from leaking into controllers, jobs, or adapters. This approach enforces strict invariants across backend service boundaries.

What is the best way to unit test business logic invariants in a backend service?▼

The best way to unit test business logic invariants is to refactor domain rules into a testable module boundary with defined inputs and outputs. This setup supports unit tests by providing deterministic error behavior through encoded preconditions and postconditions.

How do you refactor domain rules to enforce strict invariants across module boundaries?▼

Refactoring domain rules involves consolidating them into a clear API surface module that enforces invariants with preconditions and postconditions. This scalable refactoring maintains deterministic errors while ensuring rules apply uniformly across controllers and adapters.

Does encapsulating domain rules into a module boundary support scalable refactoring?▼

Yes, encapsulating domain rules into a module boundary supports scalable refactoring of business logic. By enforcing rules through a clear API surface and deterministic error behavior, the module maintains strict invariants while the surrounding backend services scale.

When do I need to consolidate business logic into a dedicated module boundary?▼

You need to consolidate business logic into a dedicated module boundary when invariants begin leaking into controllers, jobs, or adapters. This process is applicable to backend services requiring strict invariants, clear module interfaces, and deterministic unit tests.