update login

Note that the below code can't be used to change providers, so if a user uses Google to login they can only change to another Google email. You must verify they are changing to a Google managed email before proceeding. One option is to check the user.providerIds array beforehand if you utilize the saveUserData method of this library.

svelte
<script lang="ts">
  import { verifyBeforeUpdateEmail, getAuth } from 'firebase/auth';
</script>
<button type="button" on:click={() => {
  const newEmail = prompt('Whats the new email?');
  if (newEmail) {
    const auth = getAuth();
    const user = auth.currentUser;
    verifyBeforeUpdateEmail(user, newEmail, { url: 'https://sveltefirets.vercel.app/demo/account' });
  }
}}>Update Email</button>

{#if $user} {:else} You must first sign in to try it: saveUserData(e.detail)} /> {/if}

See verifyBeforeUpdateEmail docs to learn about the possible errors that you should be catching.
See https://firebase.google.com/docs/auth/web/account-linking to learn how to link accounts (add a new sign in method instead of change the email for a particular one)

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