nestjs-utils

Utility helpers for Nest.js projects. Comes with opinionated defaults for TypeORM, Swagger and serialisation:

• Symbols (e.g. DTO property names) always camelCase.
• API JSON payload property names always snake_case.
• Database column names always snake_case.

See the example app for a fully wired showcase of all features.

Important: Serialisation uses class-transformer/class-validator (see Nest.js docs). You can use the following helpers for easy setup (see also example/src/app.module.ts)

import { Module } from '@nestjs/common'
import { SERIALIZATION_INTERCEPTOR, VALIDATION_PIPE } from '@metapic/nestjs-utils'

@Module({
  providers: [SERIALIZATION_INTERCEPTOR, VALIDATION_PIPE],
})
export class AppModule {}

TypeORM views

ViewEntity and ViewColumn (from @metapic/nestjs-utils/typeorm) wrap TypeORM's decorators and apply the same snake_case convention as Column: the view name is derived from the class name and each column name from its property key, unless you pass an explicit name. The derived view name is prefixed with v_ by default - override it with prefix: 'view_' or disable it with prefix: ''.

import { ViewColumn, ViewEntity } from '@metapic/nestjs-utils/typeorm'
import { DataSource } from 'typeorm'

import { Cat } from './cat.entity'
@ViewEntity({
  // View name defaults to `v_cat_breed_stats`
  expression: (dataSource: DataSource) =>
    dataSource
      .createQueryBuilder()
      .select('cat.breed', 'breed')
      .addSelect('COUNT(*)', 'cat_count')
      .from(Cat, 'cat')
      .groupBy('cat.breed'),
})
export class CatBreedStats {
  @ViewColumn()
  breed!: string

  // Column name defaults to `cat_count` (snake_case of the property).
  @ViewColumn()
  catCount!: number
}

Testing

All testing runs through the example app’s e2e suite: example/test.