router-next does not like base with trailing slash

[ishitatsuyuki]

A reasonable setup for vue-cli with vue-next (and router) would look like this:

const router = createRouter({
  history: createWebHistory(process.env.BASE_URL),
  routes,
});

Here BASE_URL defaults to /.

In the older router there exists logic to strip the trailing slash:

https://github.com/vuejs/vue-router/blob/fc42d9cf8e1d381b885c9af37003198dce6f1161/src/history/base.js#L213-L231

This is probably gone in router-next. Therefore,

createWebHistory("/")

causes the router to attempt to pushState(.., "//"), resulting in SecurityError: The operation is insecure.

vue-router 4.0.0-alpha.5