Валидация данных

The ValidationPipe is a built-in pipe that can be used to validate data coming from the client. It uses class-validator package under the hood. The ValidationPipe provides a convenient approach to enforce validation rules for all incoming client payloads, where the specific rules are declared with simple annotations in DTO declarations in each module.

Установка

npm
Yarn
pnpm
Bun

$ npm install class-validator class-transformer

$ yarn add class-validator class-transformer

$ pnpm add class-validator class-transformer

$ bun add class-validator class-transformer

Использование

Now we can add a few validation rules in our CreateUserDto. We do this using decorators provided by the class-validator package, described in detail here. In this fashion, any route that uses the CreateUserDto will automatically enforce these validation rules.

src/users/dto/create-user.dto.ts
import { IsEmail, IsNotEmpty, IsOptional, IsString } from 'class-validator';
import { StringOption } from 'necord';

export class CreateUserDto {
    @IsString()
    @IsNotEmpty()
    @StringOption({
        name: 'name',
        description: 'Your name',
        required: true
    })
    public readonly name!: string;

    @IsOptional()
    @IsEmail()
    @StringOption({
        name: 'email',
        description: 'Your email',
        required: false
    })
    public readonly email?: string;
}

совет

Also you can use ValidationPipe for transforming and validating the payload of a request.

Read more about transforming

Now, we can use the ValidationPipe in our UsersCommands to enforce the validation rules we just defined.

src/users/users.commands.ts
import { Injectable, ValidationPipe } from '@nestjs/common';
import { Context, Options, SlashCommand, SlashCommandContext } from 'necord';
import { CreateUserDto } from './dto/create-user.dto';

@Injectable()
export class UsersCommands {
    @SlashCommand({
        name: 'create',
        description: 'Create a new user'
    })
    public async onCreateUser(
        @Context() [interaction]: SlashCommandContext,
        @Options(new ValidationPipe({ validateCustomDecorators: true })) createUserDto: CreateUserDto
    ): Promise<void> {
        await interaction.reply({ content: `User created: ${createUserDto.name}` });
    }
}

Now, if we try to use the create command without providing a name, or provide an invalid email, we will get an error message.

{"statusCode":400,"message":["email must be an email"],"error":"Bad Request"}

You can create snippet for validated options decorator:

src/decorators/validated-options.decorator.ts
import { PipeTransform, Type, ValidationPipe } from '@nestjs/common';
import { Options } from 'necord';

export const ValidatedOptions = (
    ...pipes: Array<PipeTransform | Type<PipeTransform>>
) => Options(...pipes, new ValidationPipe({ validateCustomDecorators: true }));

совет

You can create filters to handle and response validation errors.

See Exception Filters for more information

Установка​

Использование​

Установка

Использование