`cacheDir` not honored if `deps.optimizer.{mode}.enabled` is true

[Pistonight]

Describe the bug

cacheDir not honored if deps.optimizer.{mode}.enabled is true. vitest will save cache to node_modules/.vite as if cacheDir is not specified.

Reproduction

Run

npm create vite@latest
npm i

Edit the config

/// <reference types="vitest/config" />
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  cacheDir: ".vite",
  plugins: [react()],
  test: {
    deps: {
      optimizer: {
        ssr: {
          enabled: true // toggling this to repro
        }
      }
    }
  }
})

Create a test src/App.test.tsx

import { describe, expect, test } from "vitest";
describe("App", () =>{
    test("works", () => {
        expect(1).not.toBe(2);
    });
});

Run

npx vitest

1. Observe cache is unexpectedly created in node_modules/.vite.
2. Toggle test.deps.optimizer.ssr.enabled to false, and run npx vitest again
3. Observe cache is created in .vite as expected

System Info

System:
    OS: Windows 11 10.0.26120
    CPU: (32) x64 AMD Ryzen 9 5950X 16-Core Processor
    Memory: 41.33 GB / 63.91 GB
  Binaries:
    Node: 18.20.4 - ~\dotbin\extra\portable\nvm\symlink\node.EXE
    npm: 10.7.0 - ~\dotbin\extra\portable\nvm\symlink\npm.CMD
    bun: 1.1.6 - ~\.bun\bin\bun.EXE
  Browsers:
    Edge: Chromium (127.0.2651.86)
    Internet Explorer: 11.0.26100.1
  npmPackages:
    @vitejs/plugin-react: ^4.3.2 => 4.3.2
    vite: ^5.4.8 => 5.4.9
    vitest: ^2.1.3 => 2.1.3

Used Package Manager

npm

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.
• 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.

[Pistonight]

I did notice that the deprecated cache.dir option behave correctly.

Seems like it's not checking vite cacheDir here but it should?

vitest/packages/vitest/src/node/plugins/utils.ts

Lines 44 to 64 in a939779

	const cacheDir
	= testConfig.cache !== false ? testConfig.cache?.dir : undefined
	const currentInclude = testOptions.include || viteOptions?.include || []
	const exclude = [
	'vitest',
	// Ideally, we shouldn't optimize react in test mode, otherwise we need to optimize _every_ dependency that uses react.
	'react',
	'vue',
	...(testOptions.exclude || viteOptions?.exclude || []),
	]
	const runtime = currentInclude.filter(
	n => n.endsWith('jsx-dev-runtime') || n.endsWith('jsx-runtime'),
	)
	exclude.push(...runtime)
	const include = (testOptions.include || viteOptions?.include || []).filter(
	(n: string) => !exclude.includes(n),
	)
	newConfig.cacheDir
	= cacheDir ?? VitestCache.resolveCacheDir(root, cacheDir, testConfig.name)

[sheremet-va]

Seems like it's not checking vite cacheDir here but it should?

Looks like a bug indeed. PR is welcome!

[Pistonight]

Thanks for confirming, just to clarify my understanding: how do these 3 properties relate and resolve exactly?

1. Vite cacheDir
2. Vitest server.deps.cacheDir
3. Vitest cache.dir

[hi-ogawa]

As par the change #5229, the intent is to put things under cacheDir + '/vitest'. Vitest users don't need to configure server.deps.cacheDir and the others should mostly look like:

const finalCacheDir = cache.dir ?? join(cacheDir, "vitest")
                      //                ^^^^^^^^
                      // this is probably hard-coded as `node_modules/.vite`,
                      // which is a bug

By default Vite has cacheDir = 'node_modules/.vite', so Vitest uses node_modules/.vite/vitest. If you explicitly set cacheDir = '.vite', Vitest should probably use .vite/vitest.