Auto detect multiple nrepl connection options, if they exist

[zalky]

Expected behavior

I often need to connect to both a clj nrepl server as well as a shadow-cljs nrepl server for full stack dev. Because the clj nrepl server prints its port to .nrepl-port, and shadow prints its port to .shadow-nrepl/nrepl.port, ideally their respective ports should both be automatically discoverable when I try to connect via cider-connect.

Actual behavior

If a clj nrepl server has already printed its port to .nrepl-port, cider-connect will fail to auto-detect the shadow nrepl server port in .shadow-nrepl/nrepl.port. With only a shadow nrepl server running, the shadow nrepl port is automatically detected.

Steps to reproduce the problem

Make sure you have both a clj nrepl server started as well as a shadow cljs nrepl server started before you try to connect to the shadow-cljs server via cider-connect.

I'm not super familiar with the code-base, but as best I can tell the conditional in nrepl-extract-port in nrepl-client.el will always return a single result and cause .nrepl-port to shadow .shadow-nrepl/nrepl.port. nrepl-extract-port might need to return a list.

Environment & Version information

CIDER version information

;; CIDER 1.1.0 (package: 1.1.0.1) (Plovdiv), nREPL 0.8.3
;; Clojure 1.10.3, Java 1.8.0_302

Emacs version

GNU Emacs 27.2 (build 1, x86_64-apple-darwin18.7.0)

Operating system

OSX 11.6.2

[vemv]

Sounds reasonable, would you give it a shot (https://docs.cider.mx/cider/contributing/hacking.html#hacking-on-cider-elisp) and propose/draft a PR that you have verified that works for you?

[zalky]

I'll try to take a crack at it once I'm able to carve out some free time.