How to use the class-validator.MaxLength function in class-validator

@Field({ nullable: true })
  @MaxLength(24)
  @IsOptional()
  username?: string;
}

@InputType()
export class UserCreateInput {
  @Field()
  @IsEmail()
  @MaxLength(64)
  email: string;

  @Field()
  @MaxLength(24)
  username: string;

  @Field()
  @MinLength(6)
  @MaxLength(64)
  password: string;

  @Field({ nullable: true })
  name?: string;

  @Field({ nullable: true })
  country?: string;

  @Field({ nullable: true })
  city?: string;

import { Cluster as ICluster } from '@ngx-starter-kit/models';
import { Exclude } from 'class-transformer';
import { IsAscii, IsNotEmpty, IsUrl, MaxLength, MinLength } from 'class-validator';
import { Column, Entity, Index, OneToMany, RelationId } from 'typeorm';
import { AuditBase } from '../../core/entities/audit-base';
import { Project } from '../project.entity';

@Entity('cluster')
export class Cluster extends AuditBase implements ICluster {
  @IsNotEmpty()
  @IsAscii()
  @MinLength(3)
  @MaxLength(20)
  @Index({ unique: true })
  @Column({ length: 15 })
  name: string;

  @IsNotEmpty()
  @MinLength(3)
  @MaxLength(6)
  @Column({ length: 6 })
  ver: string;

  @IsNotEmpty()
  @IsUrl()
  @MinLength(10)
  @MaxLength(256)
  @Column()
  baseUrl: string;

import { ApiModelProperty } from '@nestjs/swagger';
import { Type } from 'class-transformer';
import { IsNotEmpty, MaxLength } from 'class-validator';
import { ProjectDto } from './project.dto';

export class StatusDto {
  @ApiModelProperty({ type: Number })
  id: number;

  @MaxLength(100)
  @ApiModelProperty()
  name: string;

  @MaxLength(255)
  @IsNotEmpty()
  @ApiModelProperty()
  title: string;

  @Type(() => ProjectDto)
  @IsNotEmpty()
  @ApiModelProperty({ type: ProjectDto })
  project: ProjectDto;
}

import { ApiModelProperty } from '@nestjs/swagger';
import { IsOptional, MaxLength } from 'class-validator';

export class InGroupDto {
  @IsOptional()
  id: number;

  @MaxLength(100)
  @ApiModelProperty()
  name: string;

  @MaxLength(255)
  @ApiModelProperty()
  title: string;
}

@Matches(RegExp('^[a-zA-Z0-9\\-]+$'))
  @MaxLength(32)
  @IsLowercase()
  @Column('text')
  username: string;

  @IsEmail()
  @Column('text')
  email: string;

  @IsNotEmpty()
  @Column('text')
  passwordHash: string;

  @IsNotEmpty()
  @MaxLength(20)
  @Column('text')
  firstName: string;

  @IsNotEmpty()
  @MaxLength(40)
  @Column('text')
  lastName: string;

  @IsOptional()
  @MaxLength(40)
  @Column('text', { nullable: true })
  middleName?: string;

  @IsOptional()
  @IsUrl()
  @Column('text', { nullable: true })

@Column({ name: 'access_token', length: 500 })
  @IsNotEmpty()
  @MaxLength(500)
  accessToken: string = undefined;

  @Column({ name: 'refresh_token', length: 200, nullable: true })
  @MaxLength(200)
  @IsOptional()
  refreshToken: string = undefined;

  @Column({ type: Date, name: 'expires_at', nullable: true })
  expiresAt: Date = undefined;

  @Column({ name: 'token_type', length: 200, nullable: true })
  @MaxLength(200)
  @IsOptional()
  tokenType: string = undefined;

  @Column({ length: 512, nullable: true })
  @MaxLength(512)
  @IsOptional()
  scope: string = undefined;

  @ManyToOne(type => User, { eager: true })
  @IsNotEmpty()
  @JoinColumn({ name: 'user_id' })
  user: User = undefined;

  @BeforeInsert()
  doBeforeInsertion() {
    const errors = validateSync(this, { validationError: { target: false } });

export class UserDto {
  @ApiModelProperty({ type: Number })
  id: number;

  @Exclude()
  @ApiModelPropertyOptional()
  password: string;

  @ApiModelPropertyOptional({ type: String })
  lastLogin: Date;

  @ApiModelPropertyOptional({ type: Boolean })
  isSuperuser: boolean;

  @MaxLength(150)
  @ApiModelProperty()
  username: string;

  @MaxLength(30)
  @ApiModelProperty()
  firstName: string;

  @MaxLength(30)
  @ApiModelProperty()
  lastName: string;

  @MaxLength(254)
  @ApiModelProperty()
  email: string;

  @ApiModelPropertyOptional({ type: Boolean })

import { ApiModelProperty, ApiModelPropertyOptional } from '@nestjs/swagger';
import { Type } from 'class-transformer';
import { IsNotEmpty, MaxLength } from 'class-validator';
import { UserDto } from '@rucken/core-nestjs';
import { StatusDto } from './status.dto';

export class ProjectDto {
  @ApiModelProperty({ type: Number })
  id: number;

  @MaxLength(255)
  @IsNotEmpty()
  @ApiModelProperty()
  title: string;

  @MaxLength(512)
  @ApiModelPropertyOptional()
  description: string;

  @ApiModelPropertyOptional({ type: Boolean })
  isPublic: boolean;

  @Type(() => StatusDto)
  @ApiModelProperty({ type: StatusDto, isArray: true })
  statuses: StatusDto[];

  @Type(() => UserDto)

ManyToOne,
  OneToMany,
  PrimaryGeneratedColumn,
  UpdateDateColumn
} from 'typeorm';
import { Status } from './status.entity';
import { Task } from './task.entity';

@Entity({ name: 'projects' })
export class Project {
  @PrimaryGeneratedColumn()
  id: number = undefined;

  @Column({ length: 255 })
  @IsNotEmpty()
  @MaxLength(255)
  title: string = undefined;

  @Column({ length: 512, nullable: true })
  @MaxLength(512)
  @IsOptional()
  description: string = undefined;

  @Column({ name: 'is_public', default: false })
  isPublic: boolean = undefined;

  @CreateDateColumn({ name: 'created_at', nullable: true })
  createdAt: Date = undefined;

  @UpdateDateColumn({ name: 'updated_at', nullable: true })
  updatedAt: Date = undefined;

import { ApiModelProperty, ApiModelPropertyOptional } from '@nestjs/swagger';
import { Type } from 'class-transformer';
import { IsOptional, MaxLength } from 'class-validator';
import { GroupDto } from '../dto/group.dto';

export class InCreateUserDto {
  @IsOptional()
  id: number;

  @MaxLength(128)
  @ApiModelPropertyOptional()
  password: string;

  @ApiModelPropertyOptional({ type: String })
  lastLogin: Date;

  @ApiModelProperty({ type: Boolean })
  isSuperuser: boolean;

  @MaxLength(150)
  @ApiModelProperty()
  username: string;

  @MaxLength(30)
  @ApiModelProperty()
  firstName: string;