Global validation pipe overriden in whole Resolver if overriden in single method

Bug Report

Current behavior

I have enabled validation and transformation globally via

app.useGlobalPipes(new ValidationPipe({ transform: true }));

This works just fine.

Now, I wanted to validate a simple string property without having to create a class, so I created a custom validation pipe IsNotEmptyStringPipe and used it like this inside a GraphQL mutation:

@Mutation()
async mergeGroups(
  @Args('name', IsNotEmptyStringPipe) name: string,
  @Args('groupIds') groupIds: string[]
): Promise<Group> {
  return this.graphqlService.mergeGroups({ name, groupIds });
}

This also works just fine.

BUT: After some debugging, I noticed that this causes the globally enabled validation pipe to disappear on the other methods of the same resolver.

This means in this mutation:

@Mutation()
async updateGroup(
  @Args('id') id: string,
  @Args('group') group: UpdateGroupInput
): Promise<Group> {
  return this.graphqlService.updateGroup({ id, group });
}

group is no longer transformed to a UpdateGroupInput instance as long as IsNotEmptyStringPipe exists in the other method.

Input Code

main.ts

// App setup 
// ...
app.useGlobalPipes(new ValidationPipe({ transform: true }));
// ...

group.resolver.ts

@Resolver('Group')
export class GroupResolver {
  constructor(private graphqlService: GraphqlService) {}

  @Mutation()
  async updateGroup(
    @Args('id') id: string,
    @Args('group') group: UpdateGroupInput
  ): Promise<Group> {
    return this.graphqlService.updateGroup({ id, group });
  }

  @Mutation()
  async mergeGroups(
    @Args('name', IsNotEmptyStringPipe) name: string,
    @Args('groupIds') groupIds: string[]
  ): Promise<Group> {
    return this.graphqlService.mergeGroups({ name, groupIds });
  }
}

UpdateGroupInput.dto.ts

export class UpdateGroupInput {
  @IsNotEmptyString()
  @IsOptional()
  name?: string;
  @Transform(({ value }) => (value.trim() === '' ? null : value.trim()))
  @IsOptional()
  country?: string;
  @Transform(({ value }) => (value.trim() === '' ? null : value.trim()))
  @IsOptional()
  contract?: string;
  @Transform(({ value }) => (value.trim() === '' ? null : value.trim()))
  @IsOptional()
  website?: string;
}

validation.ts

import { ArgumentMetadata, Injectable, PipeTransform } from '@nestjs/common';
import {
  ValidationOptions,
  registerDecorator,
  isNotEmpty,
  ValidationArguments,
  isString,
} from 'class-validator';

export function IsNotEmptyString(validationOptions?: ValidationOptions) {
  // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
  return (object: unknown, propertyName: string) => {
    registerDecorator({
      name: 'isNotEmptyString',
      target: object.constructor,
      propertyName,
      options: validationOptions,
      validator: {
        validate: (value: any): boolean =>
          isString(value) && isNotEmpty(value.trim()),
        defaultMessage: (validationArguments?: ValidationArguments): string =>
          `${validationArguments.property} should be a non-empty string`,
      },
    });
  };
}

@Injectable()
export class IsNotEmptyStringPipe implements PipeTransform {
  // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
  transform(value: any, metadata: ArgumentMetadata): string {
    if (!(isString(value) && isNotEmpty(value.trim()))) {
      throw Error(`${metadata.data} should be a non-empty string`);
    }
    return value;
  }
}

Expected behavior

Overriding a globally enabled validation pipe in a single method should not cause the globally enabled validation pipe to disappear in other methods. This is very confusing behaviour and took me a whole day to debug why my input is no longer transformed.

Possible Solution

Environment

Nest version: 7.6.0
Node version: v16.2.0

[ekzyis]

Okay, my minimum reproduction repo has concluded that this indeed works. So I can use

app.useGlobalPipes(new ValidationPipe({ transform: true }));

and a custom pipe on a method without the validation disappear on the other method …

Mhh, have to check what is different in my code …

[jmcdo29]

Okay, that’s one of the common culprits. Like Kamil said, if you want to discuss this further, I’ll be happy to on our Discord. Usually quicker and easier responses there in my opinion as well