NestJS Drizzle CRUD Generator

Overview

Automatically generates complete CRUD modules for NestJS applications using Drizzle ORM. Creates all necessary files following the zaccheroni-monorepo patterns: feature modules, controllers, services, Zod-validated DTOs, Drizzle schemas, and Jest unit tests.

When to Use

• Creating new entity modules with full CRUD endpoints
• Building database-backed features in NestJS
• Generating type-safe DTOs with Zod validation
• Adding services with Drizzle ORM queries
• Creating unit tests with mocked database

Instructions

Step 1: Define Entity Fields

Gather entity definition:

• Entity name (e.g., user, product, order)
• List of fields with types (see references/field-types.md for supported types)
• Required fields vs optional fields with defaults

Step 2: Run the Generator

python scripts/generate_crud.py --feature <name> --fields '<json-array>' --output <path>

Step 3: Verify Generated Files

Check that all expected files were created:

ls -la libs/server/<feature-name>/src/lib/

Expected structure:

controllers/
services/
dto/
schema/
<feature>-feature.module.ts

Step 4: Run TypeScript Compilation

cd libs/server && npx tsc --noEmit

Step 5: Execute Unit Tests

cd libs/server && npm test -- --testPathPattern=<feature-name>

Examples

Generate a User module

python scripts/generate_crud.py \
  --feature user \
  --fields '[{"name": "name", "type": "string", "required": true}, {"name": "email", "type": "email", "required": true}, {"name": "password", "type": "string", "required": true}]' \
  --output ./libs/server

Generate a Product module

python scripts/generate_crud.py \
  --feature product \
  --fields '[{"name": "title", "type": "string", "required": true}, {"name": "price", "type": "number", "required": true}, {"name": "description", "type": "text", "required": false}, {"name": "inStock", "type": "boolean", "required": false, "default": true}]' \
  --output ./libs/server

Generated Structure

libs/server/{feature-name}/
├── src/
│   ├── index.ts
│   └── lib/
│       ├── {feature}-feature.module.ts
│       ├── controllers/
│       │   ├── index.ts
│       │   └── {feature}.controller.ts
│       ├── services/
│       │   ├── index.ts
│       │   ├── {feature}.service.ts
│       │   └── {feature}.service.spec.ts
│       ├── dto/
│       │   ├── index.ts
│       │   └── {feature}.dto.ts
│       └── schema/
│           └── {feature}.table.ts

Features

Module

• Uses forRootAsync pattern for lazy configuration
• Exports generated service for other modules
• Imports DatabaseModule for feature tables

Controller

• Full CRUD endpoints: POST, GET, PATCH, DELETE
• Query parameter validation for pagination
• Zod validation pipe integration

Service

• Drizzle ORM query methods
• Soft delete support (via deletedAt column)
• Pagination with limit/offset
• Filtering support
• Type-safe return types

DTOs

• Zod schemas for Create and Update
• Query parameter schemas for filtering
• NestJS DTO integration

Tests

• Jest test suite
• Mocked Drizzle database
• Test cases for all CRUD operations

Manual Integration

After generation, integrate into your app module:

// app.module.ts
import { {{FeatureName}}FeatureModule } from '@your-org/server-{{feature}}';

@Module({
  imports: [
    {{FeatureName}}FeatureModule.forRootAsync({
      useFactory: () => ({
        defaultPageSize: 10,
        maxPageSize: 100,
      }),
    }),
  ],
})
export class AppModule {}

Dependencies

Required packages:

• @nestjs/common
• @nestjs/core
• drizzle-orm
• drizzle-zod
• zod
• nestjs-zod

Best Practices

1. Verify before commit: Always run tsc --noEmit and tests before committing generated code
2. Customize services: Add business logic to generated services after validation
3. Database migrations: Create migrations separately for generated Drizzle schemas
4. Use generated types: Reference generated types in your application code
5. Review DTOs: Adjust Zod validation rules based on your API requirements

Constraints and Warnings

• Soft delete only: Delete operations use soft delete (deletedAt timestamp). Hard deletes require manual modification
• No authentication: Generated code does not include auth guards - add them based on your security requirements
• Basic CRUD only: Complex queries, transactions, or business logic must be implemented manually
• JSON escaping: Use single quotes around the JSON array when passing fields on command line