Add unit tests for routes

**Feature request**
It would be great to have pagination for middleware.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_pagination` with default `false`.

Start by locating the route and middleware implementations, their configuration handling, and any existing route tests. Clarify how pagination should work for middleware and what responses or limits are expected; done means the enable_pagination option defaults to false, enables the agreed behavior, and is covered by unit tests.

Written by the indexing model from the issue text.