In the module resolution playground app the react import works during dev but not build

[dario-piotrowicz]

If you run the module resolution playground app in dev mode everything seems to be working fine

But if you run it in preview mode and fetch from /third-party/react you get the following error:

(which is something we've seen in the past: #22)

Something is not adding up here to me, because in the module resolution app I don't see us opting in nodejs_compat anywhere, so should this issue not be present for dev as well?

Additionally if I add

compatibility_flags = ['nodejs_compat']

to the wrangler.toml file, then both for dev and build the app breaks completely erroring that the unenv/runtime/node/process/$cloudflare module can't be found

[jamesopstad]

Additionally if I add

compatibility_flags = ['nodejs_compat']

to the wrangler.toml file, then both for dev and build the app breaks completely erroring that the unenv/runtime/node/process/$cloudflare module can't be found

You need to add unenv as a dependency if you use nodejs_compat in one of the playgrounds. I remember @petebacondarwin saying that this is just a quirk of it being in a monorepo with the plugin package. We should verify that this isn't necessary when using the published package.

[dario-piotrowicz]

This is the problematic piece of code: react code

Without nodejs_compat (which I don't think should be needed for react)

In dev, in the pre-bundled react file process.env.NODE_ENV === 'production' is already resolved for false:

But in the built output it is not:

which explains why we are encountering the problem for build but not for dev

So what I need to do now is understanding why rollup doesn't resolve process.env.NODE_ENV === 'production' to true, as I assume it should do 🤔

[dario-piotrowicz]

Ok I think this sums up the rollup issue quite well: rollup/rollup#487

[dario-piotrowicz]

Ok this seems to be working quite well:

With it the react development code does get treeshaken away! 🚀

I think this might be the appropriate solution (I can create a PR with this as a followup to #72)

[jamesopstad]

Nice! This feels like a weird one because you would expect people to run into this a lot.

[dario-piotrowicz]

Nice! This feels like a weird one because you would expect people to run into this a lot.

yeah I totally agree... 😕

I even wonder if something like this should be upstreamed in vite itself, isn't replacing process.env.NODE_ENV on build a very common behavior? it feels very weird to me that rollup does not do that 😕