I have a DTO. I need to validate user entries against some strings . Those values are coming from ENV file. I got it to work, but I also need to ignore the case.
This is the value from the env file:
SEARCH_BY_LANGUAGE="Java,Javascript"
This is my version where it works, but it is sensitive to cases:
@Expose()
@IsNotEmpty()
@ApiProperty()
@IsIn(process.env.SEARCH_BY_LANGUAGE.toLowerCase().split(","))
targetLanguage: string
Problem with this approach is that, java and Java are treated differently.
I have tried to use the @Matches, like this:
@Expose()
@IsNotEmpty()
@ApiProperty()
@Matches(`^${process.env.SEARCH_BY_LANGUAGE.split(",")}$`, 'i')
targetLanguage: string
But I am getting this error:
[ExceptionsHandler] Invalid flags supplied to RegExp constructor '^Java,Javascript$' +14493m
I feel I am close, but cant figure it out.
You have two possible approaches for that, the first one is @Transform() decorator from class-transformer, like Jay McDoniel commented above:
You can perform additional data transformation using @Transform decorator. For example, you want to make your Date object to be a moment object when you are transforming object from plain to class:
import { Transform } from 'class-transformer'; import * as moment from 'moment'; import { Moment } from 'moment'; export class Photo { id: number; @Type(() => Date) @Transform(({ value }) => moment(value), { toClassOnly: true }) date: Moment; }Now when you call plainToClass and send a plain representation of the Photo > object, it will convert a date value in your photo object to moment date. @Transform decorator also supports groups and versioning.
So you would do something like this:
@Transform((value) => value.toLowerCase() })
targetLanguage: string
Your second approach would be to use a NestJS custom interceptor and manually change your payload/data before using it