question: how to have the validate function called for custom validation decorators? #1943
Description
I was trying to use a custom validation decorators
- Added the following source code in my project, as documented here :
ValidationConstraint and decorator
import {
registerDecorator,
ValidationOptions,
ValidatorConstraint,
ValidatorConstraintInterface,
ValidationArguments,
} from 'class-validator';
@ValidatorConstraint({ async: true })
export class IsUserAlreadyExistConstraint implements ValidatorConstraintInterface {
validate(userName: any, args: ValidationArguments) {
console.log('validate')
throw new Error('validate')
}
}
export function IsUserAlreadyExist(validationOptions?: ValidationOptions) {
return function (object: Object, propertyName: string) {
registerDecorator({
target: object.constructor,
propertyName: propertyName,
options: validationOptions,
constraints: [],
validator: IsUserAlreadyExistConstraint,
});
};
}
And put it to use on my NestJS - GraphQL backend:
@InputType()
export class UserInput {
@Field(() => String, { nullable: true })
@IsUserAlreadyExist()
username: string
}
The problem:
I sent a postman request, my mutation is processed as usually and the user can be created.
However, I never pass inside the validate function. No console.log displayed. No error thrown by my backend...
Am I supposed to call it somehow manually?
Like the usage in the documentation, ie call validate on the object? (BTW, adding the call to validate didn't result in an error, so I still have the problem of validate function of my IsUserAlreadyExistContraint not being called...)
validate(post).then(errors => {
// errors is an array of validation errors
if (errors.length > 0) {
console.log('validation failed. errors: ', errors);
} else {
console.log('validation succeed');
}
});
If it must be called manually, isn't there any way to have the validation done automatically?
BR
Nicolas