generate()

Generates random valid RUT numbers for testing and development purposes.

Basic Usage#

import { generate } from 'rut.ts'
 
const randomRut = generate()
console.log(randomRut) // '18.972.631-7'

Type Signature#

function generate(): string

Parameters#

None. The function takes no parameters.

Return Value#

Returns a string containing:

• A randomly generated RUT
• Already formatted with dots and hyphen (XX.XXX.XXX-Y)
• Guaranteed to be valid (passes validate())
• Body in range: 10,000,000 - 99,999,999
• Non-suspicious body (repeated-digit placeholders are skipped)

Examples#

Generate Single RUT#

import { generate } from 'rut.ts'
 
const rut = generate()
console.log(rut) // e.g., '45.123.789-2'

Generate Multiple RUTs#

import { generate } from 'rut.ts'
 
const ruts = Array.from({ length: 10 }, () => generate())
console.log(ruts)
// ['18.972.631-7', '45.123.789-2', ...]

Generate for Testing#

import { generate, validate } from 'rut.ts'
 
// Generate test data
const testRuts = Array.from({ length: 100 }, () => generate())
 
// All generated RUTs are valid
testRuts.forEach((rut) => {
  console.assert(validate(rut) === true)
})

Seed Test Database#

import { generate, decompose } from 'rut.ts'
 
// Create test users with valid RUTs
const testUsers = Array.from({ length: 50 }, (_, i) => {
  const rut = generate()
  const { body, verifier } = decompose(rut)
 
  return {
    id: i + 1,
    name: `Test User ${i + 1}`,
    rut: rut,
    rutBody: body,
    rutVerifier: verifier,
  }
})
 
await db.users.insertMany(testUsers)

Properties#

All generated RUTs have these properties:

• ✅ Valid: Pass validate() without errors
• ✅ Formatted: Include dots and hyphen (XX.XXX.XXX-Y)
• ✅ Realistic: Body in range 10,000,000 - 99,999,999
• ✅ Random: Different on each call
• ✅ Non-suspicious: Pass validate(rut, { strict: true })
• ✅ 8-digit body: Always generates 8-digit bodies

Format#

Generated RUTs follow this pattern:

XX.XXX.XXX-Y
││  │   │  └─ Verifier digit (0-9 or K)
││  │   └──── Last 3 digits of body
││  └──────── Middle 3 digits of body
│└─────────── First 2 digits of body
└──────────── Always 8 digits total in body

Use Cases#

• ✅ Generate test data for unit tests
• ✅ Populate development databases
• ✅ Create sample data for demos
• ✅ Seed databases with realistic RUTs
• ✅ Stress testing validation logic

Examples in Testing#

import { generate, validate } from 'rut.ts'
 
describe('RUT validation', () => {
  test('validates 1000 generated RUTs', () => {
    const ruts = Array.from({ length: 1000 }, () => generate())
 
    ruts.forEach((rut) => {
      expect(validate(rut)).toBe(true)
    })
  })
 
  test('generated RUTs pass strict validation', () => {
    const ruts = Array.from({ length: 100 }, () => generate())
 
    ruts.forEach((rut) => {
      expect(validate(rut, { strict: true })).toBe(true)
    })
  })
})

Notes#

• Each call generates a different RUT (random)
• Generated RUTs use realistic number ranges
• Verifier is automatically calculated using Modulo 11
• Output is always formatted with dots and hyphen
• Web Crypto is used when available; older runtimes fall back to Math.random()
• Generated RUTs are for tests, demos, and development data. Do not use them to assign real identities.

Related Functions#

• validate() - Validate generated RUTs
• calculateVerifier() - Calculate verifier manually
• format() - Format RUTs