Request Validation

Vitek provides optional runtime validation for request body and query parameters via helpers.

Manual Validation

Use validateBody and validateQuery in your handlers. If validation fails, a ValidationError (422) is thrown:

import { validateBody, validateQuery } from "vitek-plugin";
import type { ValidationSchema } from "vitek-plugin";

export type Body = {
  title: string;
  content: string;
  authorId: number;
};

export default function handler(context: VitekContext) {
  const body = validateBody(context.body, {
    title: { type: "string", required: true, min: 1, max: 200 },
    content: { type: "string", required: true, min: 10 },
    authorId: { type: "number", required: true, min: 1 },
  });

  const query = validateQuery(context.query, {
    limit: { type: "number", min: 1, max: 100 },
    offset: { type: "number", min: 0 },
  });

  return { message: "Validated successfully", body, query };
}

Validation Rules

Each field in the schema uses a ValidationRule:

type ValidationRule = {
  type: "string" | "number" | "boolean" | "object" | "array";
  required?: boolean;
  min?: number;   // For strings: min length; for numbers: min value; for arrays: min items
  max?: number;   // For strings: max length; for numbers: max value; for arrays: max items
  pattern?: string | RegExp;  // For strings: regex pattern
  custom?: (value: any) => boolean | string;  // Custom validator
};

Validation Functions

• validate(data, schema) - Returns validation result without throwing
• validateOrThrow(data, schema) - Throws ValidationError if invalid
• validateBody(body, schema) - Validates request body
• validateQuery(query, schema) - Validates query parameters