refactor(auth): replace 2FA string sentinel with typed error

Use a dedicated TwoFactorRequiredError and shared type guard to keep login flow checks type-safe and less brittle than matching magic strings.

Made-with: Cursor

heicode/web/default/src/features/auth/api.ts

@@ -1,6 +1,10 @@
 import { api } from '@/lib/api'
 import { resetHeicodeAuthenticatedSession } from '@/features/auth/heicode-authenticated-session'
 import { saveUserId } from '@/features/auth/lib/storage'
+import {
+  isTwoFactorRequiredError,
+  TwoFactorRequiredError,
+} from '@/features/auth/errors'
 import type {
   LoginPayload,
   LoginResponse,
@@ -72,7 +76,7 @@ async function establishManagerCookieSession(payload: LoginPayload) {
     throw new Error(body?.message || 'Unable to establish Manager session')
   }
   if (body.data?.require_2fa) {
-    throw new Error('TWO_FACTOR_REQUIRED')
+    throw new TwoFactorRequiredError()
   }
   if (body.data?.id != null) {
     saveUserId(body.data.id)
@@ -151,10 +155,7 @@ export async function login(payload: LoginPayload) {
     try {
       await establishManagerCookieSession(payload)
     } catch (syncErr) {
-      if (
-        syncErr instanceof Error &&
-        syncErr.message === 'TWO_FACTOR_REQUIRED'
-      ) {
+      if (isTwoFactorRequiredError(syncErr)) {
         throw syncErr
       }
       clearHeicodeTokens()

heicode/web/default/src/features/auth/errors.ts

@@ -0,0 +1,12 @@
+export class TwoFactorRequiredError extends Error {
+  constructor() {
+    super('Two-factor authentication is required')
+    this.name = 'TwoFactorRequiredError'
+  }
+}
+
+export function isTwoFactorRequiredError(
+  error: unknown
+): error is TwoFactorRequiredError {
+  return error instanceof TwoFactorRequiredError
+}

heicode/web/default/src/features/auth/index.ts

@@ -71,6 +71,7 @@ export {
   getAffiliateCode,
   saveAffiliateCode,
 } from './lib/storage'
+export { TwoFactorRequiredError, isTwoFactorRequiredError } from './errors'
 
 export {
   isValidOTP,

heicode/web/default/src/features/auth/sign-in/components/user-auth-form.tsx

@@ -22,6 +22,7 @@ import { loginFormSchema } from '@/features/auth/constants'
 import { useAuthRedirect } from '@/features/auth/hooks/use-auth-redirect'
 import { useTurnstile } from '@/features/auth/hooks/use-turnstile'
 import { Turnstile } from '@/components/turnstile'
+import { isTwoFactorRequiredError } from '@/features/auth/errors'
 import type { AuthFormProps } from '@/features/auth/types'
 
 export function UserAuthForm({
@@ -78,10 +79,7 @@ export function UserAuthForm({
         toast.error(res.message)
       }
     } catch (error) {
-      if (
-        error instanceof Error &&
-        error.message === 'TWO_FACTOR_REQUIRED'
-      ) {
+      if (isTwoFactorRequiredError(error)) {
         redirectTo2FA()
         return
       }