Vue.js nested routing with default child

Maybe try re-arranging the children, routes are fired in the order they match from top-to-bottom, so this should hopefully fix it:

window.router = new VueRouter({
    routes: [

    ...

    {
        path: '/listings',
        name: 'listing.index',
        component: require('./components/listing/index.vue'),
        children: [
            {
                path: ':id',
                name: 'listing.show',
                component: require('./components/listing/show.vue')
            }
            {
                path: '',
                component: require('./components/listing/map.vue')
            },
        ]
    },

    ...

  ]
});

Just for a bit of clarification, your path: '' essentially serves as a "catch all", which is likely why when it's at the top it's being found immediately and so the router never propagates any further down to the :id route.

The "father" router should not be named if you want a default child route, so instead using :to="{name: 'listing.index'}", use the name of the default child route (e.g :to="{name: 'listing.map'}").

The code should look like this:

window.router = new VueRouter({
routes: [

    ...

    {
        path: '/listings',
        component: require('./components/listing/index.vue'),
        children: [
            {
                path: '',
                name: 'listing.map'
                component: require('./components/listing/map.vue')
            },
            {
                path: ':id',
                name: 'listing.show',
                component: require('./components/listing/show.vue')
            }
        ]
    },

    ...

  ]
});