False positive with destructuring depending on previous arg

[marcomorain]

version

clj-kondo v2020.02.28

platform

Native on macOS:

Darwin blaster.local 19.2.0 Darwin Kernel Version 19.2.0: Sat Nov 9 03:47:04 PST 2019; root:xnu-6153.61.1~20/RELEASE_X86_64 x86_64

editor

Calva

problem

(fn unresolved-symbol-x
  [x & {:keys [y]
          :or {y (inc x)}}]
  (+ y x))

repro

echo '(fn unresolved-symbol-x [x & {:keys [y] :or {y (inc x)}}] (+ y x))' | clj-kondo --lint -

marc@blaster ~/dev/circleci/circle $ echo '(fn unresolved-symbol-x [x & {:keys [y] :or {y (inc x)}}] (+ y x))' | clj-kondo --lint -
<stdin>:1:53: error: unresolved symbol x
linting took 19ms, errors: 1, warnings: 0

expected behavior

This code is valid as far as I understand, so no warnings.

[borkdude]

I'm closing this as this is undefined behavior and people should not rely on this.

[borkdude]

Dump from another example on Slack:

4:56 PM
oliy Hi, me again. I've found a false positive pair in unused binding field and unresolved symbol field with this:

(defn foo [k {v k}] v)
(foo :a {:a 1}) ;; -> 1

new messages
4:57 PM
(both instances of k are highlighted respectively)
5:00 PM
borkdude @oliy don't do this.
https://github.com/borkdude/clj-kondo/issues/782 (edited) 
5:01 PM
oliy Ah thank you, I searched but it was hard to know how to describe the code :)
5:01 PM
borkdude If you think this is supported by Clojure (and not just accidental behavior) talk to Alex Miller or anyone else from the core team. If they think it should be supported as official Clojure, I would be happy to fix it.
5:01 PM
But as of now it seems they don't support it.
5:01 PM
oliy Yeah I find it hard to read myself so I'm not a fan of it, but it is wonderfully terse
5:01 PM
I'll just rewrite

[borkdude]

#673 (comment):

puredanger wrote:

this is undefined and you should not do that

[borkdude]

See #916: this behavior is supported.

There are only some circumstances where this is not supported, e.g. when relying on the order in maps.
But your example was not one of them.