Output not being compiled-down

[samdenty]

Current Behavior

Currently the output is not being transpiled so it can be supported on older browsers eg. class {}.

Suggested solution(s)

Use @babel/preset-env and default to ES2015 output

Additional context

It's problematic because some setups don't transpile node_modules. This prevents extending classes from tsdx as babel doesn't like es5->es6 interop.

[swyxio]

i think @jaredpalmer has strong feelings about this one. i think it is a good idea to try to ship modern js in libraries and force downstream toolkits to change. any idea why CRA doesnt do the transpile?

edit: looks like CRA v2 does do this! see this long ass issue. facebook/create-react-app#1125 (comment)

the bar has shifted, as Dan says in that issue. “normal setups” should adjust accordingly.

[samdenty]

@sw-yx Didn't know create-react-app added that. Unfortunately some tools (parcel for one)/custom webpack setups aren't configured out the box to transpile node_modules.

How about keeping preset-env, but adding a browserlist to package.json that targets evergreen by default?

[swyxio]

🤷🏼‍♂️this is jared's call.

[jaredpalmer]

Oof. 😐

[alanrsoares]

I'm also having issues with spread operator not being transpiled

[jaredpalmer]

Will investigate in the mornjng

[jaredpalmer]

I think this must have to do with cjs settings.

[jaredpalmer]

Can someone explore this?

[hedgerh]

I can take a look, but need to gather a little context. Looks like there's a PR to add preset-env? #102

should the output be compiling down, but something's up with the cjs settings?

[jaredpalmer]

Honestly I haven’t diagnosed the root issue. What I know right now is that Formik’s old Rollup config was fine (on master), but the tsdx is not for cjs

[hedgerh]

Np. I can hunt for the root issue. I just wanted to confirm what the expected behavior is.

[hedgerh]

Figured it out. There was a tsconfigOverride declared in the typescript rollup plugin that forced target to esnext. Changed it to default to es5 and it can be declared in a tsconfig at the project level. #111