This stems from the open PR #15719 on Collection Routing.
That PR is very big and adds many new features to Rails, so I'd like to follow a conservative approach and add one feature at the time, making sure it's fully tested and backwards-compatible.
The first feature is to change the match of a path like GET /posts/1,3,4
:
- currently, Rails matches to
posts#show
with the params set toid: "1,3,4"
- the idea is instead to match to
posts#index
with the params set toids: ["1", "3", "4"]
.