import VERSION from svelte/compiler causes Cannot access "node:process.cwd" error

[bhavers]

Describe the bug

In +layout.svelte i print the svelte and sveltekit version like this

import { VERSION as VERSION_SVELTE } from 'svelte/compiler';
import { VERSION } from '@sveltejs/kit';
console.log(`running svelte version ${VERSION_SVELTE} and SvelteKit version ${VERSION}`);

After migrating from svelte 4 to 5 (currently at 5.1.15) i get the following error in the console:

client.js:2682 Module "node:process" has been externalized for browser compatibility. Cannot access "node:process.cwd" in client code. See https://vite.dev/guide/troubleshooting.html#module-externalized-for-browser-compatibility for more details.

This error is caused by the first import statement for the version of svelte. It does not stop execution, so just a minor nuisance.

Reproduction

1. Create a new sveltekit project
2. Add code to +layout.svelte
3. Access the page.
4. See error in Developer Tools console.

Logs

Full error message:
Module "node:process" has been externalized for browser compatibility. Cannot access "node:process.cwd" in client code. See https://vite.dev/guide/troubleshooting.html#module-externalized-for-browser-compatibility for more details.
warn @ client.js:2682
get @ browser-external:node:process:9
(anonymous) @ validate-options.js:18

and first 19 lines of validate-options.js (it crashes on the line that starts with rootDir.

import process from 'node:process';

/** @import { ModuleCompileOptions, ValidatedModuleCompileOptions, CompileOptions, ValidatedCompileOptions } from '#compiler' */
import * as e from './errors.js';
import * as w from './warnings.js';

/**
 * @template [Input=any]
 * @template [Output=Input]
 * @typedef {(input: Input, keypath: string) => Required<Output>} Validator
 */

const common = {
    filename: string('(unknown)'),

    // default to process.cwd() where it exists to replicate svelte4 behavior
    // see https://github.com/sveltejs/svelte/blob/b62fc8c8fd2640c9b99168f01b9d958cb2f7574f/packages/svelte/src/compiler/compile/Component.js#L211
    rootDir: string(typeof process !== 'undefined' ? process.cwd?.() : undefined),

    dev: boolean(false),

System Info

System:
    OS: macOS 15.0.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 461.45 MB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 23.1.0 - /opt/homebrew/bin/node
    npm: 10.9.0 - /opt/homebrew/bin/npm
  Browsers:
    Brave Browser: 130.1.71.118
    Chrome: 130.0.6723.117 <--- browser tested in
    Safari: 18.0.1
  npmPackages:
    svelte: ^5.1.15 => 5.1.15

Severity

annoyance

[dummdidumm]

@benmccann you added these imports in #13204, but looking at the code where it's used (validate-options.js) it doesn't make sense to import it - the compiler is supposed to be node-agnostic, and there's a check to see if process exists, yet through the import it's likely always there? Is there any harm in removing this import?

[dominikg]

+1 to remove the import (possibly needs an eslint disable rule comment to prevent it from adding it back)

however this could break deno compatibility for users that use svelte without a bundler plugin that supplies rootDir compilerOption if they don't have a process global in deno2

[benmccann]

Yeah, I think I just added those all with eslint --fix, so I guess I missed that.

https://github.com/sveltejs/svelte/blob/320ebd24d8857570b0c180752765fb1580590367/packages/svelte/src/compiler/validate-options.js#L1

Yeah, looks like it should be removed. But we might have to also tweak it to keep Deno working like:

rootDir: typeof process !== 'undefined' ? process.cwd() : (typeof Deno !== undefined ? Deno.cwd() : undefined)

We could create a constant somewhere to hold the cwd, so that we can do this consistently if there are other places we need to use the cwd in the future

[dominikg]

'Deno' in window ?!!! that reads off. surely there is no window global on deno serverside?

const cwd_parent=typeof process !== 'undefined' ? process : (typeof Deno !== undefined ? Deno : undefined);
const cwd_value = typeof cwd_parent.cwd === 'function' ? cwd_parent.cwd() : undefined;

could work but do we want to add deno specific handling without adding Deno to our test matrix?

[dominikg]

to give users a chance to shim process.cwd if we don't want to do this, we'd have call get_cwd during compile instead of eagerly determining it on module load.

[benmccann]

I think you could simplify const cwd_value = typeof cwd_parent.cwd === 'function' ? cwd_parent.cwd() : undefined; to just const cwd_value = cwd_parent?.cwd();

I'm fine with adding Deno to the test matrix if folks would like to do that. I think we should try to support it regardless as it has quite a few users and it's a single line change to do so