ValidateCreditCard.test.js

import { validateCreditCard } from '../ValidateCreditCard'

describe('Validate credit card number', () => {
  it('should throw error if card number is boolean', () => {
    const invalidCC = true
    expect(() => validateCreditCard(invalidCC)).toThrow(
      'The given value is not a string'
    )
  })
  it('returns true if the credit card number is valid', () => {
    const validCreditCard = '4111111111111111'
    const validationResult = validateCreditCard(validCreditCard)
    expect(validationResult).toBe(true)
  })
  it('should throw an error on non-numeric character in given credit card number', () => {
    const nonNumericCCNumbers = ['123ABCDEF', 'ABCDKDKD', 'ADS232']
    nonNumericCCNumbers.forEach(nonNumericCC => expect(() => validateCreditCard(nonNumericCC)).toThrow(
      `${nonNumericCC} is an invalid credit card number because ` + 'it has nonnumerical characters.'
    ))
  })
  it('should throw an error on credit card with invalid length', () => {
    const ccWithInvalidLength = ['41111', '4111111111111111111111']
    ccWithInvalidLength.forEach(invalidCC => expect(() => validateCreditCard(invalidCC)).toThrow(
      `${invalidCC} is an invalid credit card number because ` + 'of its length.'
    ))
  })
  it('should throw an error on credit card with invalid start substring', () => {
    const ccWithInvalidStartSubstring = ['12345678912345', '23456789123456', '789123456789123', '891234567891234', '912345678912345', '31345678912345', '32345678912345', '33345678912345', '38345678912345']
    ccWithInvalidStartSubstring.forEach(invalidCC => expect(() => validateCreditCard(invalidCC)).toThrow(
      `${invalidCC} is an invalid credit card number because ` + 'of its first two digits.'
    ))
  })
  it('should throw an error on credit card with luhn check fail', () => {
    const invalidCCs = ['411111111111111', '371211111111111', '49999999999999']
    invalidCCs.forEach(invalidCC => expect(() => validateCreditCard(invalidCC)).toThrow(
      `${invalidCC} is an invalid credit card number because ` + 'it fails the Luhn check.'
    ))
  })
})