clean-ns should follow the convention to not prune namespace deps when they don't have a :refer or :as definition

[RickMoynihan]

The convention came about in this clj-kondo thread:

clj-kondo/clj-kondo#241

Essentially the conclusion is to protect namespace declarations that are side-effecting from pruning (e.g. namespaces that load protocol extensions or multimethods etc) by not having them :refer anything or use an :as form.

clj-kondo and I believe some other tools already follow this convetion; it would be nice for refactor-nrepl to support this too.

I suspect it would be pretty simple to edit this function to support it?

refactor-nrepl/src/refactor_nrepl/ns/prune_dependencies.clj

Lines 118 to 122 in dbafd6e

	(defn- libspec-should-never-be-pruned? [libspec]
	(let [ns-name (str (:ns libspec))]
	(some (fn [^String pattern]
	(re-find (re-pattern pattern) ns-name))
	(:libspec-whitelist config/*config*))))

[bbatsov]

PR welcome!

[expez]

We've discussed this already in this repo and I consider it a non-issue for Clojure code. As I said over here I solve this by doing:

(ns my-ns
  (:require [clojure.string :as str]))

;; This has some really sweet side-effects that we want, because reasons
(require 'tick.timezone) 

This makes it super clear that this ns needs special consideration and requires no out-of-band knowledge about conventions.

Since people keep asking for this feature (and the solution above doesn't work for cljs) I agree with @bbatsov that a PR would be great, with the caveat that it has to be opt-in via a new setting. That way we don't create confusion for our existing user-base and leave the door open for the solution above that I find preferable when dealing with a Clojure-only project.

[vemv]

PR certainly welcome (with the mentioned constraints: should be opt-in)

Closing the issue as some time has passed, it's more manageable to have few issues in the tracker.