Passkey authentication doesn't abort on signal

1P_Dave​ I’m encountering the same issue when building a sign-in page that transitions from a conditionally mediated passkey sign-in (used before the username is known, see https://web.dev/articles/passkey-form-autofill#call_webauthn_api_with_the_conditional_flag_to_authenticate_the_user) to a scoped passkey sign-in (restricted to a specific user after the username is entered).

The conditional mediation approach relies on proper AbortController support, as outlined in the WebAuthn docs. In a single-page app, there’s no way to dismiss the unscoped 1Password prompt when transitioning to the scoped challenge. Since the challenge changes at that point, the entire flow breaks. If the user interacts with the lingering 1Password prompt, it fails because it’s still tied to the old, expired WebAuthn challenge.

Also, 1Password’s UI appears like a standard prompt during conditional mediation, which undermines its purpose. Conditional mediation is meant to stay passive until the user interacts with the username/autofill field.