Ecto NestedPreloadTest

Related thread: https://elixirforum.com/t/nested-preload-with-condition/5605/

This is a Phoenix 1.3rc project.

Setup

1. Install all deps as usual
2. Create Repo
3. mix ecto.migrate
4. mix run priv/repo/seeds.exs for generated test data
5. Check localhost:4000/api/branches for results. Every product has only one category and branch. However, all products appear throughout all categories and branches.

The erroneous query with_categories can be found in lib/nested_preload_test/shop/branch.ex and is used in lib/nested_preload_test/shop/shop.ex inside the list_branches function.