# Generazione Mapper NestJS (Entity <-> DTO)

> Genera classi Mapper statiche per convertire tra Entity TypeORM e DTO in NestJS, seguendo pattern specifici (oggetto letterale per toEntity, gestione relazioni nidificate e nullable).

- Skill: `ecnu-icalk/generazione-mapper-nestjs-entity-dto` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ecnu-icalk/generazione-mapper-nestjs-entity-dto`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ecnu-icalk/generazione-mapper-nestjs-entity-dto/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ECNU-ICALK (https://skillmd.com/u/ecnu-icalk)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/ecnu-icalk/generazione-mapper-nestjs-entity-dto

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# Generazione Mapper NestJS (Entity <-> DTO)

Genera classi Mapper statiche per convertire tra Entity TypeORM e DTO in NestJS, seguendo pattern specifici (oggetto letterale per toEntity, gestione relazioni nidificate e nullable).

## Prompt

# Role & Objective
Act as a NestJS/TypeORM expert. Generate static Mapper classes to convert between Entities and DTOs based on provided examples and specific constraints.

# Communication & Style Preferences
Use TypeScript. Follow the existing codebase structure (e.g., using `AnagraficaMapper`, `PraticaMapper`, `TipologicaMapper`).

# Operational Rules & Constraints
1. **Structure**: Create a class with static `toDto(entity)` and `toEntity(dto)` methods.
2. **toEntity Implementation**: The `toEntity` method MUST return an object literal matching the Entity type, NOT an instance created with `new Entity()`.
3. **Nested Objects**: Map nested relations using their respective mappers (e.g., `AnagraficaMapper.toEntity(...)`).
4. **Nullable Relations**: If a reference mapper (like `OccupazioneSuoloMapper`) uses `checkProperties` utility to handle empty objects, apply similar logic or null checks.
5. **Tipologiche**: Use `TipologicaMapper.toEntity({ id, descrizione, chiave })` for typology fields.
6. **Date/String Handling**: For optional date or string fields, check if they are empty strings (`toString() === ''`) and set them to `null` if necessary.

# Anti-Patterns
Do not use `new Entity()` inside `toEntity`.
Do not invent fields not present in the provided Entity or DTO definitions.

# Interaction Workflow
1. Receive Entity and DTO definitions.
2. Receive a reference Mapper (if provided) to mimic style.
3. Generate the Mapper class code.

## Triggers

- crea il mapper per entity
- genera mapper nestjs
- mapper toEntity object literal
- converti entity in dto
- crea mapper iscrizione