compress option in terser inside production es rollup config produces invalid JS

[swyxio]

Current Behavior

here is my repo i'm working on https://github.com/sw-yx/react-netlify-identity-widget/tree/rollupProductionIssue

if you:

yarn build
yarn link
cd example
yarn && yarn link "react-netlify-identity"
yarn start

you will see this error:

however if you change the package.json to use the development versions:

it works!!

to me this indicates a rollup config issue.

Expected behavior

the production output should work the same as development output

Suggested solution(s)

i think this could be a terser bug. or a setting that is incompatible with React.

here is the offending unexpected token - prettified for easier reading

i'm not sure what rollup setting caused this but it definitely only exists in the production build.

Your environment

Software	Version(s)
TSDX	0.3.4
TypeScript	3.4.4
Browser	chrome
npm/Yarn	yarn
Operating System	osx

[swyxio]

i went and disabled compress inside the terser settings and that fixed it:

trying to figure out what makes it go wrong

[TrySound]

@sw-yx Does it look similar to you?
terser/terser#333

[swyxio]

i saw your issue, yes it does look similar.

[jaredpalmer]

What should we do here since it is downstream?

[swyxio]

what's the size impact on you if you turn off compress? i dont have the option because my code plain doesnt work without it (and its not like i'm doing some crazy nonidiomatic React stuff). as far as i can see, thats the only option for now, and i pray @TrySound can figure it out.

We can also choose to document it as well as how to patch the package, for early adopters of TSDX who may run into this.

[TrySound]

To be honest terser code is a mess. I can't find a fix for that. You may turn off collapse_vars option. It should fix the problem.

[swyxio]

ohh i see. i thought there was no option available. thank you i will try that.

[jaredpalmer]

So what should we do for now?

[swyxio]

@jaredpalmer i have verified that Bogdan's solution works. i recommend adopting it in tsdx and have PR'ed accordingly