Hi, thanks for this PR.

I'm not familiar with the underlying issue and I couldn't reproduce#8279. There isn’t a failing test demonstrating the bug in this PR.

Could you add a minimal failing test that reproduces the problem and show why it happens?

This adds a proxy module that overridesurl_for to route hash options through Rails.application.routes

At a glance, overridingurl_for (plus the many condition branches to make it work) feels like a heavy-handed solution. Before accepting a global override of such a core helper, I'd like to understand the root cause better and see whether a smaller, more targeted change could fix it. Or, maybe this behavior should be documented as a current limitation.

@javierjulio and@mgrunberg any thought?

@craigmcnamara thank you for attempting to address this. I noticed the test suite is failing for the comments resource still.

@tagliala in general I don't know much about engines. The reason for why it fails makes sense. I implementedisolate_namespace because it's what the Rails guide suggests and to help address code reloading issues. I anticipated that there would be some potential issues here. I could only find that it required me to usemain_app proxy in Devise templates but that was it since I rely on the default admin namespace.

Could you add a minimal failing test that reproduces the problem and show why it happens?

The reproduction is in spec/requests/custom_namespace_routes_spec.rb

If you remove the overrides those fail. My production app successfully loads ActiveAdmin with the patches and fails exactly like the bug report without them.

My understanding is when routing params are omitted the routes helper infers them from the current request in the controller or view context. It seems the way the routes are used in ActiveAdmin, the helper doesn't always have the request context and that info isn't picked up.

This isn't my first foray into ActiveAdmin, I wrote the patch that allows unlimited sized CSV downloads by implementing a streaming response back in the v1 days.