Set production or development in conditions

[benmccann]

It would be nice if conditions always included development or production

E.g. vite build will automatically set the production condition while vite dev will automatically set the development condition. Rollup also sets the development and production conditions by default.

References:
https://vite.dev/config/shared-options#resolve-conditions
https://vite.dev/guide/env-and-mode#node-env-and-modes

Libraries like Svelte rely on this to be set. This works automatically in Vite and Rollup, but requires extra configuration in esbuild

If the user has not provided either production or development then set production by default or development if NODE_ENV === 'development'

[hyrious]

esbuild doesn't check NODE_ENV in its Go code. It does set process.env.NODE_ENV = "production" when all minification options are enabled. Maybe the same logic can be applied to the conditions field.

[benmccann]

That seems reasonable as conditions and NODE_ENV should always be in sync as it would cause confusion to have their values differ

[evanw]

Libraries like Svelte rely on this to be set. This works automatically in Vite and Rollup, but requires extra configuration in esbuild

Can you provide more information? Specifically: What breaks when you don't configure this in esbuild, and for what packages? Marking this issue as unactionable as it doesn't include any reproduction instructions. I'm also not seeing either the strings development or production in svelte/package.json (specifically here).

[hyrious]

@evanw It is in svelte's dependency esm-env's package.json.

I also have a trivial demo using svelte ssr which requires certain configurations to make the dev build work.

IMO, it is fine to NOT having this feature implemented because Node.js doesn't change runtime conditions by NODE_ENV too. On the other hand, for the specific package, esm-env, it also has reasonable fallbacks for no conditions case.

[benmccann]

The main problem users will encounter is warnings that they have set neither the production nor development condition.

Users may also miss out on development warnings if they are running in development and do not set the corresponding condition:
https://github.com/search?q=repo%3Asveltejs%2Fsvelte+dev+esm-env+&type=code