this-as unexpectedly binds js/window when used within function with post-condition

Question

Adding a post-condition to any function that uses cljs.core/this-as will unexpectedly cause this-as's "this" symbol to be bound to the root object (e.g., js/window) instead.

{code:none}
(defn f-no-post-condition [argument]
  (this-as this
    (js/console.log argument this)))

(defn f-with-post-condition [argument]
  {:post [true]}
  (this-as this
    (js/console.log argument this)))

(def test-object
  #js {:methodNoPostcondition f-no-post-condition
       :methodWithPostcondition f-with-post-condition})

(f-with-post-condition "A") ; Correctly prints js/window
(.methodNoPostcondition test-object "B") ; Correctly prints test-object
(.methodWithPostcondition test-object "C") ; Incorrectly prints js/window

Answer 1

Comment made by: dnolen

This is almost certainly a different manifestation of CLJS-719.

Answer 2

_Comment made by: thheller_

Just looked at the generated javascript. As David mentioned the problem is the extra function generated to get the result for the :post condition.


dummy.f_no_post_condition = (function f_no_post_condition(argument){
var this$ = this;
var G__82157 = argument;
var G__82158 = this$;
return console.log(G__82157,G__82158);
});
dummy.f_with_post_condition = (function f_with_post_condition(argument){
var _PERCENT_ = (function (){var this$ = this;
var G__82161 = argument;
var G__82162 = this$;
return console.log(G__82161,G__82162);
})();


return _PERCENT_;
});
dummy.test_object = {"methodWithPostcondition": dummy.f_with_post_condition, "methodNoPostcondition": dummy.f_no_post_condition};
dummy.f_with_post_condition("A");
dummy.test_object.methodNoPostcondition("B");
dummy.test_object.methodWithPostcondition("C");

Answer 3

Reference: https://clojure.atlassian.net/browse/CLJS-1123 (reported by alex+import)