False positive suspicious-expression

[emlyn]

The following code:

(ns testing.core-test
  (:require [clojure.test :refer :all]
            [testing.core :refer :all]))

(defn func [f] "")

(deftest b-test
  (is (instance? String (func +))))

Causes the following failure:

== Eastwood 0.2.2 Clojure 1.8.0 JVM 1.8.0_31
Directories scanned for source files:
  src test
== Linting testing.core ==
== Linting testing.core-test ==
Entering directory `/Users/emlyn/testing'
test/testing/core_test.clj:8:7: suspicious-expression: + called with 0 args.  (+) always returns 0.  Perhaps there are misplaced parentheses?
== Warnings: 1 (not including reflection warnings)  Exceptions thrown: 0
Subprocess failed

Even though the + is never called.

[emlyn]

Also, changing func to actually call f, e.g.

(defn func [f]
  (str (f 1 2)))

(deftest b-test
  (is (instance? String (func +))))

Still fails with "suspicious-expression: + called with 0 args", even though it is only ever called with 2 args.

[emlyn]

I tried adding a config file with:

(disable-warning
 {:linter :suspicious-expression
  :for-macro 'clojure.core/+
  :if-inside-macroexpansion-of #{'clojure.test/is}})

But it doesn't suppress this warning, is it because + is not a macro? Any way I can fix it?