@pliant/core

The core package provides the validation engine, built-in rules, and utilities. It has zero dependencies and works in any JavaScript environment.

Installation

npm install @pliant/core

Exports

Registry Functions

Export	Description
createRegistry()	Create a new rule registry
addRules(registry, rules)	Add rules to a registry
evaluateRules(registry, value, ctx, rules)	Validate a value

Rule Factories

Export	Description
requiredRule(options?)	Creates a required rule
emailRule(options?)	Creates an email rule
numericRule()	Creates a numeric-only rule
lengthRule(options)	Creates a length rule
minLengthRule(options)	Creates a min length rule
maxLengthRule(options)	Creates a max length rule
rangeRule(options)	Creates a numeric range rule
minRule(options)	Creates a minimum value rule
maxRule(options)	Creates a maximum value rule
regexRule(options)	Creates a regex pattern rule
equalsRule(options?)	Creates an equality rule

Helpers

Export	Description
inheritRule(parent, overrides)	Create a rule inheriting from another
createMessageResolver(catalog)	Create a message resolver
applyMessages(errors, ctx, resolver)	Apply messages to errors

Quick Example

import {
  createRegistry,
  addRules,
  evaluateRules,
  applyMessages,
  createMessageResolver,
  requiredRule,
  emailRule,
  lengthRule
} from '@pliant/core';

// Setup
const registry = createRegistry();
addRules(registry, {
  required: requiredRule(),
  email: emailRule(),
  username: lengthRule({ min: 3, max: 20 })
});

const messages = createMessageResolver({
  required: 'Required',
  email: 'Invalid email',
  length: (d) => `Must be ${d.min}-${d.max} chars`
});

// Validate
const errors = evaluateRules(registry, 'ab', { field: 'username' }, ['username']);
const resolved = applyMessages(errors, {}, messages);
// { username: { code: 'length', min: 3, max: 20, actual: 2, message: 'Must be 3-20 chars' } }

TypeScript Support

Full TypeScript support with generic types:

import type { RuleDef, ErrorDetail, Context, Registry } from '@pliant/core';

See TypeScript Types for detailed type information.