Skip to main content

⚡ Zero-Boilerplate TypeORM CRUD Generator (@nest-yalc-2/crud-gen)

💡 1. What It Is & Architectural Purpose​

@nest-yalc-2/crud-gen is the automated REST and GraphQL code generation module for NestJS 11+. It was designed to eliminate up to 40% of repetitive controller, resolver, service, DTO, and query builder boilerplate for TypeORM database entities, while maintaining full developer control over authorization and middleware.

⚙️ 2. What It Does & Key Features​

  • Automated REST Endpoints: Generates getMany, getOne, createOne, updateOne, deleteOne endpoints automatically.
  • Automated GraphQL Queries & Mutations: Produces strongly-typed GraphQL schemas, input DTOs, and field resolvers.
  • Dynamic SQL Query Parsing: Translates HTTP query strings (e.g. filter[age][gte]=18&sort=-createdAt) into optimized TypeORM WHERE, ORDER BY, and JOIN clauses.
  • Pagination Support: Automatic cursor-based or offset-based pagination.

🔬 3. How It Works Under the Hood​

flowchart TD
    Entity["@Entity() Product Decorator"]
    CrudMacro["@CrudGenEntity() Metadata Processor"]
    RouterBuilder["Dynamic Controller & Resolver Factory"]
    TypeORM["TypeORM QueryBuilder Engine"]

    Entity --> CrudMacro
    CrudMacro --> RouterBuilder
    RouterBuilder --> TypeORM
  1. Metadata Reflection: Decorating a TypeORM entity with @CrudGenEntity() registers entity metadata and route configuration choices.
  2. Dynamic Factory Pattern: On NestJS application bootstrap, the crud-gen factory dynamically instantiates REST controllers and GraphQL resolvers with dependency injection into TypeORM repositories.

🧠 4. Why It Was Designed This Way (CrudGen vs Manual Scaffolding)​

Dimension⚡ @nest-yalc-2/crud-gen🐢 Manual NestJS Scaffolding
Endpoint Setup Time< 2 minutes per Entity2-4 hours per Entity
MaintainabilityCentralized (Modify Entity to Update API)Dozens of files to sync (DTO, Service, Controller, Resolver)
Dynamic FilteringNative SQL Query Filtering SupportRequires Handwritten QueryBuilder Logic

🚀 5. Practical Usage Guide & Extended Code Examples​

import { Entity, PrimaryGeneratedColumn, Column, CreateDateColumn } from 'typeorm';
import { CrudGenEntity } from '@nest-yalc-2/crud-gen';

@Entity('products')
@CrudGenEntity({
  routes: ['getMany', 'getOne', 'createOne', 'updateOne', 'deleteOne'],
  graphql: { enabled: true }
})
export class Product {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column()
  sku: string;

  @Column()
  name: string;

  @Column('decimal', { precision: 10, scale: 2 })
  price: number;

  @CreateDateColumn()
  createdAt: Date;
}

⚠️ 6. Anti-Patterns: How NOT to Use It​

  1. ❌ DO NOT expose all CRUD routes on sensitive entities without Auth Guards: Enabling deleteOne or updateOne without applying @UseGuards() exposes public data mutation endpoints.
  2. ❌ DO NOT use crud-gen for complex business workflows requiring Sagas: For operations involving payment providers or multi-step sagas, write a custom Controller/Resolver instead of standard CRUD logic.

💡 7. Pro-Tips & Best Practices​

[!TIP] Customizing Generated Routes: You can override or extend any automatically generated route by declaring a custom Controller extending the base class produced by crud-gen.