ValidationError

Kind: Interface

Source: packages/common/interfaces/external/validation-error.interface.ts

Part of: Common

Validation error description.

ValidationError describes a failed validation result for a single property on an object. It captures the validated target, invalid value, violated constraints, optional validation contexts, and nested errors for child objects or arrays.

Properties

Diagram

mermaid
graph LR
  A[ValidationError] --> B[target: Record]
  A --> C[property: string]
  A --> D[value: any]
  A --> E[constraints: constraint messages]
  A --> F[contexts: constraint metadata]
  A --> G[children: ValidationError[]]

  G --> H[Nested property errors]
  E --> I[Validation failure messages]

Usage

ts
import type { ValidationError } from '@your-package/common';

const error: ValidationError = {
  target: {
    email: 'invalid-email',
  },
  property: 'email',
  value: 'invalid-email',
  constraints: {
    isEmail: 'email must be a valid email address',
  },
  contexts: {
    isEmail: {
      code: 'INVALID_EMAIL',
    },
  },
  children: [],
};

function formatValidationError(validationError: ValidationError): string[] {
  const messages = Object.values(validationError.constraints ?? {});

  return [
    ...messages,
    ...validationError.children.flatMap(formatValidationError),
  ];
}

console.log(formatValidationError(error));
// ['email must be a valid email address']

AI Coding Instructions

• Preserve nested validation failures in children; do not discard them when formatting errors for nested DTOs or array elements.
• Treat constraints and contexts as potentially absent or empty when consuming validation results.
• Use property together with parent error paths to build complete field paths such as address.street.
• Avoid exposing target or raw value directly in API responses when they may contain sensitive data.
• Keep constraint keys aligned with the validation library or custom validator names that produced the error.