Module's function gets rewritten

[fildahui]

• Rollup Version: 1.31.0
• Operating System (or Browser): Windows 10
• Node Version (if applicable): 10.13.0
• Link to reproduction (IMPORTANT, read below): https://repl.it/@fildahui/FantasticLongPoint

I'm creating a react component using fabric-ui-react lib and for some reason a function from fabric modules gets its body rewritten when bundling (and won't work after that). I'm using two plugins rollup-plugin-babel and @rollup/plugin-node-resolve.
Babel plugin has the option exclude: 'node_modules/**' so it's not affecting the dependencies.

This is the function of fabric module:

This is the function after bundling with rollup:

Expected Behavior

Modules functions shouldn't be changed

Actual Behavior

The function body is rewritten and many lines are stripped out

I noticed that if I manually edit the source module and change this

var _a = getIcon(iconName) || {
        subset: {},
        code: undefined
}, code = _a.code, subset = _a.subset;

to this:

var _a = getIcon(iconName);
_a = _a || {
        subset: {},
        code: undefined
};
var code = _a.code, subset = _a.subset;

The bundled output is correct and the function is not changed.

[fildahui]

Hi @lukastaegert is there any update on this?

[lukastaegert]

Did not find time to look into this yet

[lukastaegert]

Very simplified repro: https://rollupjs.org/repl/?version=2.0.4&shareable=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

[lukastaegert]

Thanks for spotting it, there was indeed a small but nasty bug at the source of it, fix at #3438