Validation

Any application that requires input from client, runs a validation before performing any action on it. We love how NestJS provides Validation Pipe and makes it so simple to apply validation.

In this boilerplate, there are few extra added validators, which you can use as per your requirement.

BaseValidator

info

This is just an alternative solution for ValidationPipe, if you wish to continue using DTOs and ValidationPipe, please feel free to do so.

All available decorators will still work for you. 😀

This boilerplate includes a BaseValidator class, which can be used to run validators inside the Services/Providers.

Usage:

import { Injectable } from '@nestjs/common';
import { BaseValidator } from '@app/support/validator';
import { CreateUser } from '../validator';

@Injectable()
export class UserService {
  constructor(private validator: BaseValidator) {}

  async create(
    inputs: Record<string, any>,
  ): Promise<Record<string, any>> {
    await this.validator.fire(inputs, CreateUser);
    // add your logic here...
  }
}

CreateUser is just our DTO that you will need to create to define the schema of incoming payload. To learn, how you can create DTOs, click here.

Available Decorators

Exists

Checks if property is available in the db on the specified table and column.

Options

Option	Description	Default
table	Name of the table	undefined
column	Column in the table	undefined
caseInsensitive	Will run case insensitive query, if true	false
where	extra where clause, will be added in the query, passed as Object	undefined

import { Exists } from '@app/core/validator';

export class UpdateUser {
  @Exists({ table: 'users', column: 'contactNumber' })
  contactNumber: number;
}

IsUnique

Checks if property is unique or not in the db on the specified table and column.

Options

Option	Description	Default
table	Name of the table	undefined
column	Column in the table	undefined
caseInsensitive	Will run case insensitive query, if true	false
where	extra where clause, will be added in the query, passed as Object	undefined

import { IsUnique } from '@app/core/validator';

export class CreateUser {
  @IsUnique({ table: 'users', column: 'contactNumber' })
  contactNumber: number;
}

IsEqualToProp

Compares the value of the property to another property in the same class.

import { IsString, IsEqualToProp } from '@app/core/validator';

export class ForgotPassword {
  @IsString()
  password: string;
  
  @IsEqualToProp('password') // name of the property to be compared with
  confirmPasssword: string;
}

IsValueFromConfig

It is very common to store global configuration values in the Config module and there can be use-case where you may want to compare some property with some property stored in config.

import { IsValueFromConfig } from '@app/core/validator';

export class UpdateDeliveryStatus {
  @IsValueFromConfig({ key: 'settings.delivery.status' })
  status: number;
}

IsDateInFormatConstraint

Use this decorator if you want to validate the format of the date/timestamp.

info

Uses moment package internally.

import { IsDateInFormat } from '@app/support/validator';

export class UpdateProfile {
  @IsDateInFormat('DD-MM-YYYY')
  dob: string;
}

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