Error handler for prisma

[DiegoSHS]

Implementation suggest

I find this concept a cool idea, but we can make this more efficient and compact

Upgrades

we can upgrade the PrismaErrorHandler class by following this steps

• Use Injectable decorator
• Replace switch with a key-value object
• Return directly the response object

  Implementation

  @Injectable()
  export class PrismaErrorHandler {
  private readonly defaultMessages = {
      'P2000': 'El valor proporcionado para la columna es demasiado largo',
      'P2001': 'Registro no encontrado',
      'P2002': 'Violación de unicidad (El registro ya existe)',
      'P2003': 'Violación de la restricción de clave externa',
      'P2004': 'Violación de la restricción de chequeo',
      'P2005': 'Valor no válido',
      'P2006': 'Valor almacenado no válido',
      'P2007': 'Error inesperado de la base de datos',
      'P2008': 'Error en la consulta a la base de datos',
      'P2009': 'Error en la validación de datos',
  }
  private readonly notHandledError = 'Error no manejado';
  private readonly errorText = 'Error en la operación';
  /**
   * Method to handle errors from Prisma.
   * @param error Error to handle
   * @returns Error message
   */
  public handleError(error: any | PrismaClientKnownRequestError): { error: string; message: string, data: null } {
      if (error instanceof PrismaClientKnownRequestError) {
          const message: string = this.defaultMessages[error.code] || this.notHandledError;
          return {
              error: this.errorText,
              message,
              data: null,
          };
      }
      return {
          error: this.errorText,
          message: 'Error inesperado',
          data: null,
      };
  }
  }

  This is a similar aproach as the custom exception filter that we used in the past

  Using in a service

  Injection of the PrismaErrorHandler as a provider

  @Module({
  providers: [/*...other providers */, ExampleService, PrismaErrorHandler],
  controllers: [ExampleController],
  })
  export class ExampleModule {}

  Using with the actual service

  @Injectable()
  export class ExampleService {
  constructor(private prisma: PrismaService, private readonly errorHandler: PrismaErrorHandler) {}
  async serviceMethod ( ): Promise<{ message: string | null; error: string | null; data: any | null }> {
  try {
    /* prisma logic */
  } catch (error) {
    return this.errorHandler.handleError(error);
  }
  }
  }

_Originally posted by @DiegoSHS in https://github.com/CADELmx/GPD_BACKEND/discussions/23#discussioncomment-10041088_

[DiegoSHS]

Validación de errores de prisma

[DiegoSHS]

Override of existent functionalities

Some of the current functionalities do the same error handeling of some of the cases in this proposal of implementation Existing functionalities that can be replaced or removed from the proposal:

• Error for P2001: The validator for foreign keys do this validation end avoid the error to be handled by prisma.
• Error for P2002: There's a validation for some insert operations that checks if the record exists
• Error for P2003: the validator for foreign keys do this validation and avoid the error to be handled by prisma

  Possible update for the proposal

  I have two possible ways to do this

• Delete the existent validators for the specific cases for prisma errors and let this validator to provide all the messages
• Delete that cases of the prisma error handler and just update the implementation to send specific messages for every data resource

_Originally posted by @DiegoSHS in https://github.com/CADELmx/GPD_BACKEND/discussions/23#discussioncomment-10078089_