handler-specification

version	1.0.0
description	Implementation guide for complying with the 4-layer separation principle and handler specification standards of Mocking GUI
name	handler-specification

Skill: Mocking GUI Handler Pattern (Spec-Driven Implementation)

The standard pattern for engineers writing Mocking GUI handlers in a format that the Mocking GUI engine can recognize.

1. Core Competencies

• Atomic Implementation: Defining specifications via HandlerConfigOption constants instead of calling msw directly.
• 4-Layer Separation: Ensuring maintainability of large-scale mock data through separation of concerns.
• HandlerType Awareness: Distinguishing between MANUAL (responseVariants) / AUTO (responseVariantsFn) / SWAGGER (swaggerResponseVariants) modes.

2. Reference & Detailed Specs

• Handler Specification: HandlerConfigOption Detailed Specification
• Architecture Standard: Mocking GUI Internal Layer Structure

3. Decision Tree / Standard Workflow

• Q1. Real-time control (toggle, manipulation) from the GUI is required? -> Action: Define with HandlerConfigOption and register in the mocks array.
• Q2. Multiple static response cases exist? -> Action: Configure MANUAL mode with a responseVariants[] array.
• Q3. Dynamic responses based on request parameters are required? -> Action: Configure AUTO mode with a responseVariantsFn function.
• Q4. Non-JSON response (HTML, Binary, etc.)? -> Action: Use the rawBody field (kind: 'html' | 'text' | 'binary' | ...).
• Q5. Migrating an existing MSW project? -> Action: Map http.xxx call statements 1:1 to HandlerConfigOption properties.
• Q6. Non-HTTP protocols (GraphQL/WebSocket, etc.) are required? -> Action: Outside the current library scope. Requires a separate raw MSW configuration.

4. Engineering Constraints & Mandates

• "All handler layers must be clearly separated into Handlers, Constants, Factories, and Utils."
• "Direct raw MSW calls are prohibited. All handlers must be defined in HandlerConfigOption format."
• "All handler names (name) must be uniquely named to avoid duplicates."
• "Cross-origin APIs must use absolute URL paths (including domain)."