Alias usages not detected from keywords in quoted forms

[milankinen]

Hi and thanks for this great tool! Here is a small issue we found while using it:

version

clj-kondo v2020.07.29

platform

Native version / OSX and Linux

problem

It seems that alias usages from quoted forms are not registered. If alias is used only in quoted form (real life example case: Datomic queries), clj-kondo gives warning: namespace <ns> is required but never used. However, if we remove the require, the code won't work anymore because reader can't recognize keyword without it.

We've solve this by so far by using fully qualified keywords but it's a bit annoying because some of the namespaces can be quite long.

repro

Here is a very basic code reproducing the issue (uses default configs):

(ns org.tsers.example
  (:require [datomic.api :as d]
            [org.tsers.user :as user]))

(defn find-users-by-country [db country]
  (d/q '[:find [?user-id ...]
         :in $ ?country 
         :where [?user ::user/country ?country]
                [?user ::user/id ?user-id]]
        db country))

expected behavior

I'd expect the code to be linted without warnings, instead I get

$ ./clj-kondo --lint example.clj 
example.clj:3:14: warning: namespace org.tsers.user is required but never used
linting took 10ms, errors: 0, warnings: 1

[borkdude]

A small workaround for now is to add a top-level keyword ::user/foo or use this config:

https://github.com/borkdude/clj-kondo/blob/master/doc/config.md#exclude-required-but-unused-namespace-from-being-reported

[milankinen]

Yes we've indeed considered those as well but decided not to use them because of the possibility to accidentally cause false negatives by forgetting the references/exclusions while doing code refactors. Having to write the fully qualified keyword name is a bit annoying but at least it's robust over time and easier to maintain.

[borkdude]

Fixed on master.

[milankinen]

Wow that was fast! Thank you!