Library mode does not respect the --mode flag

[juliushuck]

Describe the bug

I'm using the vite library mode in my monorepo to build the common packages between front and backend.

For development I used: vite build --mode development

and for production: vite build

After upgrading to vite 4, both commands seem to replace import.meta.env.PROD with true, before, it replaced it with false in development mode.

The replacement depending on the mode works in non library mode as far as I can tell

Reproduction

https://github.com/juliushuck/vite-issue/settings

Steps to reproduce

I have added the two commands i use in the package.json scripts

System Info

System:
  OS: macOS 13.0
  CPU: (10) arm64 Apple M1 Pro
  Memory: 76.44 MB / 16.00 GB
  Shell: 5.8.1 - /bin/zsh
Binaries:
  Node: 16.16.0 - ~/.nvm/versions/node/v16.16.0/bin/node
  Yarn: 3.3.0 - /opt/homebrew/bin/yarn
  npm: 8.11.0 - ~/.nvm/versions/node/v16.16.0/bin/npm
Browsers:
  Chrome: 108.0.5359.98
  Firefox: 105.0.3
  Safari: 16.0

Used Package Manager

npm

Logs

No response

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[bluwy]

This is expected in Vite 4. vite build will default to PROD by default, the mode defines the different type of build. If you want to get the old behaviour, you can set NODE_ENV=development in .env.development like in https://vitejs.dev/guide/env-and-mode.html#modes

[juliushuck]

Ok,

so I set NODE_ENV=development in .env-development. The import.meta.env.PROD value did not change, but .MODE changed to development. So I could use that, but I do not want to have to create .env files in my common packages every time I clone the repo, because I have other values in those .env files that I can not push to GitHub.

So I tried around and got this working:

const checkIsProductionMode = () => process.env.NODE_ENV === "production";

To be honest, I do not even know why it works, because I thought process is a node thing and does not work in the browser. But with that, it uses the --mode flag of the command I run the final package with (the one that uses the common package build output).

[bluwy]

so I set NODE_ENV=development in .env-development. The import.meta.env.PROD value did not change

Ah this is a bug. I found the cause.

So I could use that, but I do not want to have to create .env files in my common packages every time I clone the repo, because I have other values in those .env files that I can not push to GitHub.

You can put the secrets in .env.development.local instead. .env.development can be commited to git.

[juliushuck]

You can put the secrets in .env.development.local instead. .env.development can be commited to git.

Ah, that's the trick, will use that with import.meta.env.MODE === "production" for now then