fill.ts

1import { isVisible } from "./detect";2import { extractDomain } from "../shared/domain";34function getRegistrableDomain(hostname: string): string {5  return extractDomain(hostname) ?? hostname;6}78function checkFormAction(form: HTMLFormElement | null, expectedDomain: string): boolean {9  if (!form?.action) return true;10  try {11    const actionUrl = new URL(form.action);12    const actionDomain = getRegistrableDomain(actionUrl.hostname);13    if (actionDomain !== expectedDomain) {14      return false;15    }16  } catch {}17  return true;18}1920export function fillFields(21  usernameEl: HTMLInputElement | null,22  passwordEl: HTMLInputElement | null,23  username: string,24  password: string,25  form?: HTMLFormElement | null,26  expectedDomain?: string27): void {28  if (expectedDomain && form && !checkFormAction(form, expectedDomain)) {29    return;30  }31  // Fill username regardless of visibility — on SPA step-by-step login flows32  // the username input may be visually hidden but still tracked by the form.33  if (usernameEl && username) {34    setNativeValue(usernameEl, username);35  }36  if (passwordEl && isVisible(passwordEl)) {37    setNativeValue(passwordEl, password);38  }39}4041// React tracks input values via a synthetic event system that does not see42// direct `.value =` assignment. We must call the native HTMLInputElement43// value setter (pulled off the prototype) and then dispatch the real input44// and change events so React re-reads the new value. Without this, the45// field reads as empty to the form's controlled-input state.46export function setNativeValue(47  el: HTMLInputElement | HTMLTextAreaElement,48  value: string49): void {50  const proto =51    el instanceof HTMLTextAreaElement52      ? window.HTMLTextAreaElement.prototype53      : window.HTMLInputElement.prototype;54  const nativeValueSetter = Object.getOwnPropertyDescriptor(proto, "value")?.set;55  nativeValueSetter?.call(el, value);56  el.dispatchEvent(new Event("input", { bubbles: true }));57  el.dispatchEvent(new Event("change", { bubbles: true }));58}5960export interface CardFillFields {61  number: HTMLInputElement | null;62  expMonth: HTMLInputElement | null;63  expYear: HTMLInputElement | null;64  expiryCombo: HTMLInputElement | null;65  cvc: HTMLInputElement | null;66  name: HTMLInputElement | null;67}6869export function fillCardForm(fields: CardFillFields, card: { cardNumber: string; expMonth: string; expYear: string; cvc: string; cardholderName: string }): void {70  const raw = card.cardNumber.replace(/\s/g, '');71  if (fields.number) setNativeValue(fields.number, formatCardNumber(raw));72  if (fields.expiryCombo) {73    setNativeValue(fields.expiryCombo, `${card.expMonth}/${card.expYear.slice(-2)}`);74  } else {75    if (fields.expMonth) setNativeValue(fields.expMonth, card.expMonth);76    if (fields.expYear) setNativeValue(fields.expYear, card.expYear);77  }78  if (fields.cvc) setNativeValue(fields.cvc, card.cvc);79  if (fields.name) setNativeValue(fields.name, card.cardholderName);80}8182export function formatCardNumber(raw: string): string {83  if (/^3[47]/.test(raw)) return raw.replace(/(\d{4})(\d{6})(\d{5})/, '$1 $2 $3');84  return raw.replace(/(\d{4})(?=\d)/g, '$1 ').trim();85}8687export function detectCardNetwork(number: string): import('../shared/types').CardNetwork {88  const n = number.replace(/\s/g, '');89  if (/^4/.test(n)) return 'visa';90  if (/^5[1-5]|^2[2-7]/.test(n)) return 'mastercard';91  if (/^3[47]/.test(n)) return 'amex';92  if (/^6(?:011|5)/.test(n)) return 'discover';93  return 'unknown';94}9596export function passesLuhn(number: string): boolean {97  const digits = number.replace(/\s/g, '').split('').map(Number);98  let sum = 0, isEven = false;99  for (let i = digits.length - 1; i >= 0; i--) {100    let d = digits[i]!;101    if (isEven) { d *= 2; if (d > 9) d -= 9; }102    sum += d;103    isEven = !isEven;104  }105  return sum % 10 === 0;106}107108export function extractLast4(number: string): string {109  return number.replace(/\s/g, '').slice(-4);110}