isPreview is always false

[hyunbinseo]

Describe the bug

Both vite dev and vite preview passes isPreview: false.

• feat!: add isPreview to ConfigEnv and resolveConfig #14855

It was implemented to distinguish these two, and it seems to be broken.

import { defineConfig } from 'vite';

export default defineConfig((config) => {
  console.log(config);
  return {};
});

# npm run dev
{
  mode: 'development',
  command: 'serve',
  isSsrBuild: false,
  isPreview: false
}

# npm run preview
{
  mode: 'production',
  command: 'serve',
  isSsrBuild: false,
  isPreview: false
}

Reproduction

https://stackblitz.com/edit/vitejs-vite-qgb5dt?file=vite.config.js

Steps to reproduce

No response

System Info

System:
  OS: Linux 5.0 undefined
  CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Memory: 0 Bytes / 0 Bytes
  Shell: 1.0 - /bin/jsh
Binaries:
  Node: 18.18.0 - /usr/local/bin/node
  Yarn: 1.22.19 - /usr/local/bin/yarn
  npm: 10.2.3 - /usr/local/bin/npm
  pnpm: 8.14.0 - /usr/local/bin/pnpm
npmPackages:
  vite: ^5.0.11 => 5.0.12

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.

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-qgb5dt (Open reproduction)

[bluwy]

Looks like I forgot to pass the isPreview param here 🤦 (5th param of resolveConfig)

vite/packages/vite/src/node/preview.ts

Lines 103 to 111 in 3c9cab6

	export async function preview(
	inlineConfig: InlineConfig = {},
	): Promise<PreviewServer> {
	const config = await resolveConfig(
	inlineConfig,
	'serve',
	'production',
	'production',
	)

Feel free to send a PR!