Issue with "esm-env" package after update

[nikitaiavdeev]

Describe the bug

dev command is causing an error after recent update of the "esm-env" package to the version 1.1.1

The reason is that in node_modules\svelte\src\internal\server\context.js

import { DEV } from 'esm-env';

DEV = false after 'esm-env' update

and it is causing an error on line 64

if (DEV) {
  // component function
  current_component.function = fn;
}

Reproduction

need reproduction

Logs

TypeError: Cannot read properties of undefined (reading 'Symbol(filename)')
    at Module.push_element (\node_modules\.pnpm\svelte@5.1.4\node_modules\svelte\src\internal\server\dev.js:70:70)

System Info

"devDependencies": {
		"@sveltejs/adapter-static": "^3.0.6",
		"@sveltejs/kit": "^2.7.3",
		"@sveltejs/vite-plugin-svelte": "^4.0.0",
		"@tailwindcss/typography": "^0.5.15",
		"@types/eslint": "^9.6.1",
		"@types/wicg-file-system-access": "^2023.10.5",
		"autoprefixer": "^10.4.20",
		"bits-ui": "1.0.0-next.32",
		"clsx": "^2.1.1",
		"eslint": "^9.13.0",
		"eslint-config-prettier": "^9.1.0",
		"eslint-plugin-svelte": "^2.46.0",
		"formsnap": "2.0.0-next.0",
		"globals": "^15.11.0",
		"prettier": "^3.3.3",
		"prettier-plugin-svelte": "^3.2.7",
		"prettier-plugin-tailwindcss": "^0.6.8",
		"svelte": "^5.1.4",
		"svelte-check": "^4.0.5",
		"svelte-radix": "^2.0.1",
		"sveltekit-superforms": "^2.20.0",
		"tailwind-merge": "^2.5.4",
		"tailwind-variants": "^0.2.1",
		"tailwindcss": "^3.4.14",
		"tailwindcss-animate": "^1.0.7",
		"typescript": "^5.6.3",
		"typescript-eslint": "^8.12.2",
		"vite": "^5.4.10",
		"zod": "^3.23.8"
	},
	"dependencies": {
		"lucide-svelte": "^0.454.0",
		"mode-watcher": "^0.4.1"
	},

Severity

blocking an upgrade

[dominikg]

are you sure you are using esm-env@1.1.1 ? just tried it with a new project created by pnpm dlx sv that uses esm-env 1.1.1 and it did not fail.

[dominikg]

force downgrading to esm-env 1.1.0 gave me this error instead:

failed to load config from /home/dominikg/develop/reproductions/sv-new/vite.config.ts
error when starting dev server:
Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'node-conditions' imported from /home/dominikg/develop/reproductions/sv-new/node_modules/.pnpm/esm-env@1.1.0/node_modules/esm-env/index.mjs
    at packageResolve (node:internal/modules/esm/resolve:854:9)
    at moduleResolve (node:internal/modules/esm/resolve:927:18)
    at defaultResolve (node:internal/modules/esm/resolve:1169:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:542:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:510:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:239:38)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:96:40)
    at link (node:internal/modules/esm/module_job:95:36)
 ELIFECYCLE  Command failed with exit code 1.
 ```
 
 which makes more sense looking at the 1.1.0 release and the subsequent 1.1.1 fix.
 
 please share your project including package-lock file and commands you ran to get that error

[benmccann]

Yeah, pretty sure you need to upgrade to 1.1.1 to fix this and you're actually using 1.1.0

[PatrickG]

There are multiple people reporting this error on the discord as well. One of them created this repro.

But this has revealed a bug(?) if there is a discrepancy between the dev option that is passed to the compiler and DEV from esm-env.
current_component.function is only set if DEV (from esm-env) is true: https://github.com/sveltejs/svelte/blob/main/packages/svelte/src/internal/server/context.js#L62-L65
And push_element is called[¹][²] if dev (the compiler option) is true

Shouldn't we rather use the compiler option dev here as well?

[benmccann]

This only affects Astro. I'm not sure why though

[benmccann]

Hmm. Or maybe not: huntabyte/bits-ui#839. But it didn't happen in my own SvelteKit project

This is truly bizarre. Might have to go back to the old style conditions, though they 2x the number of files in esm-env for every new condition created...

[benmccann]

I have absolutely no idea why esm-env 1.1.1 doesn't work, but esm-env 1.1.2 should

[nikitaiavdeev]

Could confirm that after release of the esm-env 1.1.2 everything works perfectly.
@benmccann Thanks a lot for pushing that update