CLJS-1324: Compiler fails to raise warning/error when invoking a keyword without arguments

Warn during analyses when invoking a keyword without any arguments

Author: sgrove

src/main/clojure/cljs/analyzer.cljc

@@ -2188,12 +2188,15 @@
   (let [enve (assoc env :context :expr)
         fexpr (analyze enve f)
         argc (count args)
-        ^boolean fn-var? (-> fexpr :info :fn-var)]
-    (when fn-var?
+        ^boolean fn-var? (-> fexpr :info :fn-var)
+        kw? (= 'cljs.core/Keyword (:tag fexpr))]
+    (when (or fn-var? kw?)
       (let [{:keys [^boolean variadic max-fixed-arity method-params name]} (:info fexpr)]
-        (when (and (not (valid-arity? argc method-params))
-                   (or (not variadic)
-                       (and variadic (< argc max-fixed-arity))))
+        (when (or (and kw? (zero? argc))
+                  (and (not kw?)
+                       (not (valid-arity? argc method-params))
+                       (or (not variadic)
+                           (and variadic (< argc max-fixed-arity)))))
           (warning :fn-arity env {:name name :argc argc}))))
     (let [deprecated? (-> fexpr :info :deprecated)
           no-warn? (-> form meta :deprecation-nowarn)]

src/test/clojure/cljs/analyzer_tests.clj

@@ -13,7 +13,8 @@
 (def warning-forms
   {:undeclared-var (let [v (gensym)] `(~v 1 2 3))
    :fn-arity '(do (defn x [a b] (+ a b))
-                  (x 1 2 3 4))})
+                  (x 1 2 3 4))
+   :keyword-arity '(do (:argumentless-keyword-invocation))})
 
 (defn warn-count [form]
   (let [counter (atom 0)