Rollup produces invalid code (from some valid code produced by babel-minify)

[tex0l]

Hi!
When I try to rollup this:

global.foo=()=>{return!1,null};

I get this:

'use strict';

global.foo=()=>{returnnull};

Which is invalid, and I would have expected something like this:

'use strict';

global.foo=()=>{return null};

Here is the test case to reproduce:
https://github.com/tex0l/bug-report-rollup

The input snippet of the test case was produced by using babel-minify@0.4.3 on this — though I'm not sure why it produces that — (check the commit history, I initially thought it was a problem with rollup-plugin-babel):

global.foo = () => {
  const bar = {}
  if (false) {}
  return null
}

[lukastaegert]

Hi @tex0l, thank you for making us aware of this!
As the person responsible for this, this is obviously a glaring oversight on our part. In fact, the same issue can be triggered in other situations as well:

https://rollupjs.org/repl?version=0.59.0&shareable=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

Will have to think about this a little 🤔

[lukastaegert]

If you install rollup via npm i rollup/rollup#missing-space, it should be working. Hope we can release this soon.

[arantes555]

I can confirm I ran into the same issue, more precisely while using rollup & babel-minify on vuejs.

(My build worked in dev, and not in prod, which was kind of mind-blowing. It was actually because, as is advised by vuejs, I replaced process.env.NODE_ENV by 'production' in prod, which triggered DCE, which triggered the bug)

@lukastaegert : I can also confirm that my build works with rollup/rollup#missing-space! Looking forward to seeing this released :)

[lukastaegert]

It is released already ☺️

[arantes555]

Damn, you released it literally one minute before I posted my comment, that was fast 😜 incredible job guys ! Thanks :)