validate()

Validates a given RUT string, checking both format and verifier digit.

Basic Usage


import { validate } from 'rut.ts'
 
validate('12.345.678-5') // true
validate('12.345.678-0') // false (wrong verifier)
validate('invalid')      // false

Type Signature


function validate(rut: unknown, options?: ValidateOptions): boolean
 
type ValidateOptions = {
  strict?: boolean
}

Parameters

rut (unknown) - The RUT to validate. Accepts unknown types for type safety.
options (optional) - Validation options
- strict (boolean, default: false) - If true, rejects suspicious patterns

Return Value

Returns boolean:

true if the RUT is valid
false if the RUT is invalid or not a string

Examples

Basic Validation


import { validate } from 'rut.ts'
 
// Valid RUTs
validate('12.345.678-5')   // true
validate('12345678-5')     // true (without dots)
validate('123456785')      // true (no formatting)
validate('14.625.621-K')   // true (K verifier)
 
// Invalid RUTs
validate('12.345.678-0')   // false (wrong verifier)
validate('abc')            // false
validate('')               // false
validate(null)             // false
validate(123)              // false

Strict Mode

Strict mode rejects suspicious patterns like repeated digits:


import { validate } from 'rut.ts'
 
// Suspicious RUTs (technically valid, but unlikely to be real)
validate('11.111.111-1', { strict: true })  // false
validate('22.222.222-2', { strict: true })  // false
validate('33.333.333-3', { strict: true })  // false
 
// Without strict mode, these pass
validate('11.111.111-1')  // true
validate('22.222.222-2')  // true

Type Safety

The function accepts unknown input for better type safety:


import { validate } from 'rut.ts'
 
function processUserInput(input: unknown) {
  if (validate(input)) {
    // TypeScript doesn't narrow type here, but validation passes
    console.log('Valid RUT')
  }
}
 
processUserInput('12.345.678-5')  // Valid RUT
processUserInput(12345678)        // Silent fail (returns false)
processUserInput(null)            // Silent fail (returns false)

Use Cases

✅ Form validation
✅ API input validation
✅ Database validation before storage
✅ Type-safe validation with unknown inputs
✅ Detecting test/placeholder RUTs with strict mode

format() - Format a RUT string
clean() - Remove formatting
isRutLike() - Quick format check without validation