Async onBeforeRouteLeave composition-api in-component navigation guard

[avenmore]

What problem does this feature solve?

This would allow code returning a promise to be waited for before cancelling or allowing the route change to happen. The documentation example for this navigation guard (https://next.router.vuejs.org/guide/advanced/composition-api.html#navigation-guards) uses window.confirm() which is not flexible an not likely to suit the application style.

What does the proposed API look like?

Example usage:

import { onBeforeRouteLeave } from 'vue-router';

onBeforeRouteLeave(async () => {
    if (await myDialog.prompt('Save changes')) {
        if (await saveChanges())
            return true;
    }
    return false;
})

Currently (4.0.3) this does not wait.

[posva]

This should work so open a bug report with a boiled down reproduction instead

[avenmore]

Confirmed that it does currently work. The fault was in my prompt dialog and what it returned.