CLJS-2307: Closure warns on unreachable checked array code

Author: mfikes

src/main/cljs/cljs/core.cljs

@@ -439,26 +439,28 @@
 
 (defn- checked-aget
   ([array idx]
-   (try
-     (assert (or (array? array) (js/goog.isArrayLike array)))
-     (assert (number? idx))
-     (assert (not (neg? idx)))
-     (assert (< idx (alength array)))
-     (catch :default e
-       (maybe-warn e)))
+   (when-assert
+     (try
+       (assert (or (array? array) (js/goog.isArrayLike array)))
+       (assert (number? idx))
+       (assert (not (neg? idx)))
+       (assert (< idx (alength array)))
+       (catch :default e
+         (maybe-warn e))))
    (unchecked-get array idx))
   ([array idx & idxs]
    (apply checked-aget (checked-aget array idx) idxs)))
 
 (defn- checked-aset
   ([array idx val]
-   (try
-     (assert (or (array? array) (js/goog.isArrayLike array)))
-     (assert (number? idx))
-     (assert (not (neg? idx)))
-     (assert (< idx (alength array)))
-     (catch :default e
-       (maybe-warn e)))
+   (when-assert
+     (try
+       (assert (or (array? array) (js/goog.isArrayLike array)))
+       (assert (number? idx))
+       (assert (not (neg? idx)))
+       (assert (< idx (alength array)))
+       (catch :default e
+         (maybe-warn e))))
    (unchecked-set array idx val))
   ([array idx idx2 & idxv]
    (apply checked-aset (checked-aget array idx) idx2 idxv)))

src/main/clojure/cljs/core.cljc

@@ -2290,6 +2290,9 @@
            ~@(mapcat (core/fn [[m c]] `((cljs.core/= ~m ~esym) ~c)) pairs)
            :else ~default)))))
 
+(core/defmacro ^:private when-assert [x]
+  (core/when *assert* x))
+
 (core/defmacro assert
   "Evaluates expr and throws an exception if it does not evaluate to
   logical true."