BUG: new 'Mangle variables to reduce code size' no longer does ANY minifying/mangling within IIFE

[DarrenSem]

With both of these checkboxes selected...
[x] Wrap in an IIFE (anonymizing function).
[x] Mangle variables to reduce code size. (formerly called "Minify code using Babel Minify."

...there seems to be a regressive bug introduced by today's update.

Test case:

  var key = "href";
  var foo = location[key];
  var bar = foo + "#";
  foo += "?";
  console.log(bar);;;

Result from newly-updated version @ https://chriszarate.github.io/bookmarkleter/

javascript:void function () {var key="href",foo=location.href,bar=foo+"#";foo+="?",console.log(bar);}();

Compare to result from previous version e.g. https://alanhogan.github.io/bookmarkleter/

javascript:void function(){var a=location.href,b=a+"#";a+="?",console.log(b)}();

[chriszarate]

There's a bit of a catch-22. Babel won't mangle vars in the global scope, because they could be needed in other code. Wrapping the code in a IIFE means they aren't in the global scope, but we have already passed the code through the minifier—because if we don't, we run into syntax issues. I think you were on to something with the line break, but I need to test a few things out.

[DarrenSem]

My suggestion: remove the latest "comments: false" commit, and then just make ${code}}(); become ${code}\n}(); -- then I can test a few examples to confirm that fixes the minor annoyance WITHOUT completely breaking minifying :-)

[DarrenSem]

There's a bit of a catch-22. Babel won't mangle vars in the global scope, because they could be needed in other code. Wrapping the code in a IIFE means they aren't in the global scope, but we have already passed the code through the minifier—because if we don't, we run into syntax issues. I think you were on to something with the line break, but I need to test a few things out.

I would like to add a couple of tests so the mangling/minifying can be validated as working with and without ending // (and also with and without its own wrapping IIFE). Should I edit one of the existing files in the /test/ folder or create a new one?

[chriszarate]

I've just pushed up some changes that I think put things in a better place, including your original suggestion of adding the line break to the IIFE. Mangling (now linked with the deadcode option) is now the default and should follow the previous behavior.

I agree that more and better tests are needed, I'd be grateful if you wanted to contribute some. Thanks for all the feedback.

[DarrenSem]

Great! Sooo nice to see you spending time on getting this handiest-ever tool updated with some modern additions to JS. I'm glad my comments have been helpful and not overwhelming or annoying :-)

I saw a test file called "mangleVars.js" so I think that will be what I add to.