Add ability to dynamically add child routes

[smares]

Version

3.0.1

Reproduction link

https://jsfiddle.net/qv9z3x99/

Steps to reproduce

vue-router has a method addRoutes that allows to dynamically add routes. However, it is currently not possible to add child routes to an existing route as far as I can see. It would be nice if addRoutes could have a second parameter parent or if you could introduce a new addChildRoutes method.

What I am trying to achieve is create a route for a product, let's say '/products/productA' pointing to a component that dynamically adds child routes in its beforeCreate so that in the end, I can navigate to '/products/productA/settings', '/products/productA/dashboard' etc. without the main router config knowing about every route each product has.

What is expected?

addRoute should offer a second parameter called parent so one can add child routes

What is actually happening?

addRoute does not support adding child routes to routes already defined

[posva]

Duplicate of #1156