Testing availability of function abs and constant cljs.core/Cons in nbb after adding entries to core.cljs' clojure.core namespace map

test-cons-abs.cljs

;; Test file to verify cljs.core/Cons and abs availability in nbb
;; Run with: nbb test-cons-abs.cljs
;;
;; Expected output WITHOUT fix:
;;   Test 1 (abs): ERROR - Could not resolve symbol
;;   Test 2 (Cons): ERROR - Could not resolve symbol
;;
;; Expected output WITH fix:
;;   Test 1 (abs): 42
;;   Test 2 (Cons): shows constructor function
;;   Test 3 (instance?): true

(println "=== Testing cljs.core/Cons and abs in nbb ===")
(println)

;; 1. Test abs - use resolve to check at runtime
(println "1. Test abs:")
(if-let [abs-fn (resolve 'abs)]
  (println "   (abs -42) =" (@abs-fn -42))
  (println "   ERROR: Could not resolve symbol: abs"))
(println)

;; 2. Test cljs.core/Cons directly - use resolve
(println "2. Test cljs.core/Cons directly:")
(if-let [cons-var (resolve 'cljs.core/Cons)]
  (let [cons-type (if (var? cons-var) @cons-var cons-var)]
    (println "   cljs.core/Cons =" cons-type))
  (println "   ERROR: Could not resolve symbol: cljs.core/Cons"))
(println)

;; 3. Test instance? with cljs.core/Cons
(println "3. Test (instance? cljs.core/Cons (cons 1 [])):")
(if-let [cons-var (resolve 'cljs.core/Cons)]
  (let [cons-type (if (var? cons-var) @cons-var cons-var)]
    (println "   Result:" (instance? cons-type (cons 1 []))))
  (println "   ERROR: Cannot test - cljs.core/Cons not resolved"))
(println)

;; 4. Workaround that should work
(println "4. Workaround (type (cons 1 [])):")
(println "   (instance? (type (cons 1 [])) (cons 2 [])):" 
         (instance? (type (cons 1 [])) (cons 2 [])))
(println)

(println "=== Done ===")