Validation Rules

Since 1.5.0

Types for validation and sanitization of data.

Overview

Validation Rules provides types for building type-safe validation systems with field validators, custom rules, and schema builders. It supports string, number, array, and object validation with composable rules.

This module enables building comprehensive validation pipelines with proper TypeScript inference. It includes types for validation errors, constraints, and sanitization rules for data transformation.

Basic Usage

import type { Validator, StringFieldValidator, SchemaBuilder, ValidationRule } from 'uni-types'

// String validator
type EmailValidator = StringFieldValidator<string>

// Custom validation rule
type EmailRule = ValidationRule<string>

// Schema builder pattern
type UserSchema = SchemaBuilder

Key Types

Validator

Base validator interface.

type Validator<T = unknown> = {
  validate: (value: unknown) => ValidatorResult<T>
  optional: () => Validator<T | undefined>
  nullable: () => Validator<T | null>
}

StringFieldValidator

String field validator with chainable methods.

type StringFieldValidator<T = string> = Validator<T> & {
  minLength: (length: number) => StringFieldValidator<T>
  maxLength: (length: number) => StringFieldValidator<T>
  pattern: (regex: RegExp) => StringFieldValidator<T>
  email: () => StringFieldValidator<T>
  url: () => StringFieldValidator<T>
  oneOf: (values: T[]) => StringFieldValidator<T>
}

NumberFieldValidator

Number field validator with constraints.

type NumberFieldValidator<T = number> = Validator<T> & {
  min: (value: number) => NumberFieldValidator<T>
  max: (value: number) => NumberFieldValidator<T>
  integer: () => NumberFieldValidator<T>
  positive: () => NumberFieldValidator<T>
  multipleOf: (value: number) => NumberFieldValidator<T>
}

ObjectFieldValidator

Object field validator for shape validation.

type ObjectFieldValidator<T = Record<string, unknown>> = Validator<T> & {
  shape: <S extends Record<string, Validator>>(schema: S) => ObjectFieldValidator<{ ... }>
  partial: () => ObjectFieldValidator<Partial<T>>
  strict: () => ObjectFieldValidator<T>
}

SchemaBuilder

Schema builder for constructing validators.

type SchemaBuilder = {
  string: () => StringFieldValidator
  number: () => NumberFieldValidator
  boolean: () => BooleanFieldValidator
  array: <U>(validator?: Validator<U>) => ArrayFieldValidator<U[]>
  object: <S extends Record<string, Validator>>(schema?: S) => ObjectFieldValidator
}

Related

• API Reference
• Config - Configuration types