Vite fatal error when a variable in .env ends with "$", even if it is not accessible by Vite.

[Amixx]

Describe the bug

I have a project where a single .env file is used by both vite and symfony (PHP). There is a variable for symfony that ends with "$".
Might be a regression of this: #6858

Expectation: npm install && npm run dev runs successfully - starts devserver
Reality: npm install && npm run dev fails with the following output:

up to date, audited 16 packages in 528ms

4 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

> vite-bug-error-if-env-file-contains--@0.0.0 dev
> vite

error when starting dev server:
Error: dotenv-expand failed to expand env vars. Maybe you need to escape `$`?
    at loadEnv (file:///home/imants/IssueReproductions/vite-bug-error-if-env-file-contains-$/node_modules/vite/dist/node/chunks/dep-3007b26d.js:44346:19)
    at resolveConfig (file:///home/imants/IssueReproductions/vite-bug-error-if-env-file-contains-$/node_modules/vite/dist/node/chunks/dep-3007b26d.js:61877:9)
    at async createServer (file:///home/imants/IssueReproductions/vite-bug-error-if-env-file-contains-$/node_modules/vite/dist/node/chunks/dep-3007b26d.js:61127:20)
    at async CAC.<anonymous> (file:///home/imants/IssueReproductions/vite-bug-error-if-env-file-contains-$/node_modules/vite/dist/node/cli.js:734:24)

Reproduction

https://github.com/whitedigital-eu/vite-bug-error-if-env-file-contains--

Steps to reproduce

Install packages and run development environment: npm install && npm run dev

System Info

System:
    OS: Linux 5.15 Ubuntu 22.04.1 LTS 22.04.1 LTS (Jammy Jellyfish)
    CPU: (8) x64 AMD Ryzen 7 4700U with Radeon Graphics
    Memory: 11.25 GB / 22.71 GB
    Container: Yes
    Shell: 5.1.16 - /bin/bash
  Binaries:
    Node: 16.17.0 - ~/.nvm/versions/node/v16.17.0/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v16.17.0/bin/yarn
    npm: 8.15.0 - ~/.nvm/versions/node/v16.17.0/bin/npm
  Browsers:
    Chromium: 109.0.5414.119
    Firefox: 109.0.1
  npmPackages:
    vite: ^4.1.0 => 4.1.1

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[bluwy]

This is intentional to how dotenv-expand works. It thinks that the $ is a variable that it tries to expand, however it can't so it reports the error. You can fix it with:

VITE_FOO=foobar\$

[acirulis]

Hi, Vite documentation also states that "[..] Only VITE_SOME_KEY will be exposed as import.meta.env.VITE_SOME_KEY to your client source code, [..]".

Basically .env file (as single source for project configuration) may contain variables that are completely outside of scope for Vite/javascript source code. Therefore escaping them might not be possible or would require changes in unrelated code (e.g. Symfony framework, as OP suggested.). Wouldn't it be possible to enfore dotenv-expand only on VITE_* variables?

[bluwy]

After discussion with @patak-dev, we think it might be worth skipping for private variables. That would mean patching dotenv-expand, but it should be possible.

[sun0day]

After discussion with @patak-dev, we think it might be worth skipping for private variables. That would mean patching dotenv-expand, but it should be possible.

Skipping for private variables will cause an error when VITE_ variables depend on them.

VITE_KEY=$PRIVATE_KEY
PRIVATE_KEY=xxxxx

To avoid impacting irrelevant private variables, I think patching dotenv-expand to be compatible with /^VITE_.*\$$/ is enough.