'a is undefined' when compiling a cljs prj with an NPM module under :prod profile

Question

I followed this howto: http://blob.tomerweller.com/reagent-import-react-components-from-npm and it worked great. I even managed to use one of my own NPM module on top of this example app of re-frame: https://github.com/Day8/re-frame/tree/master/examples/simple/

Starting the resulting app with:

lein clean && lein figwheel

everything works ok, but when I do:

lein do clean, with-profile prod compile

I get a TypeError: a is undefined . Any idea to fix this?

Let me provide you with the code: the bad commit is here , while both :dev and :prod profiles work OK at this just previous commit .

Update : I managed to fix the compiled version like this (see the commit ):

  return d.c?d.c(c,v,w):d.call(null,c,v,w)}}(G,r,b,c,d,e)),I=dw(G);rf.b?: […]
  };w.b=v;w.c=f;return w}()}(c,d,e,f))};hf.b(ow,ik);hf.b(ow,bp);hf.b(ow,To); […]
  function nx(a){var b=window.deps["react-mathjax"],
-    c=window.deps.clubexpr.kf;
+    c=window.deps.clubexpr.renderLispAsLaTeX;
  return new U(null,3,5,V,[Vj,b.Context,new U(null,4,null)}
  function Wv(){return function(a){return function(){return new U(null,6,5,V,[…]

This seems to me a compilation misconfiguration or bug.

Update 2 : my code compiles OK if I set :optimizations to :simple (was :advanced ). See the cljs compiler doc about this option .

Thanks.

Answer 1

The code that is failing is here .

It looks like you might need to provide externs for clubexpr, so that the Closure Compiler knows not to rewrite renderLispAsLatex as kf . When compiling under :simple, the Closure Compiler doesn't rewrite function names, so this problem wouldn't show up.

As a side note, you probably shouldn't use aget to get objects from the window, aget is designed for array access only. To get objects, you should use goog.object/get . See this post on Checked Array Access for more info on this.