Vitest doesn't discover tests when pointed at monorepo root

[roryschadler]

Describe the bug

I have a yarn-workspace-powered monorepo which has vitest installed in both of the packages as well as the root. When I run yarn test /absolute/path/vitest-non-root-monorepo/typescript-project (with/without trailing slash), I get the following error:

yarn test /Users/roryschadler/testing/vitest-non-root-monorepo/typescript-project/       

 DEV  v1.4.0 /Users/roryschadler/testing/vitest-non-root-monorepo/typescript-project

filter:  /Users/roryschadler/testing/vitest-non-root-monorepo/typescript-project/
[client] Config
include: **/*.{test,spec}.?(c|m)[jt]s?(x)
exclude:  **/node_modules/**, **/dist/**, **/cypress/**, **/.{idea,git,cache,output,temp}/**, **/{karma,rollup,webpack,vite,vitest,jest,ava,babel,nyc,cypress,tsup,build,eslint,prettier}.config.*
[server] Config
include: **/*.{test,spec}.?(c|m)[jt]s?(x)
exclude:  **/node_modules/**, **/dist/**, **/cypress/**, **/.{idea,git,cache,output,temp}/**, **/{karma,rollup,webpack,vite,vitest,jest,ava,babel,nyc,cypress,tsup,build,eslint,prettier}.config.*
watch exclude:  **/node_modules/**, **/dist/**

No test files found, exiting with code 1

If I run yarn test /absolute/path/vitest-non-root-monorepo/typescript-project/client or ...client/, the tests under client run just fine.

Reproduction

https://github.com/roryschadler/vitest-non-root-monorepo

System Info

System:
    OS: macOS 14.4
    CPU: (10) arm64 Apple M1 Max
    Memory: 257.94 MB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.6.1 - ~/.nvm/versions/node/v20.6.1/bin/node
    Yarn: 3.6.3 - ~/.nvm/versions/node/v20.6.1/bin/yarn
    npm: 9.8.1 - ~/.nvm/versions/node/v20.6.1/bin/npm
  IDEs:
    Emacs: 29.2 - /opt/homebrew/bin/emacs
    VSCode: 1.87.2 - /usr/local/bin/code
    Vim: 9.0 - /usr/bin/vim
    Xcode: /undefined - /usr/bin/xcodebuild
  Browsers:
    Chrome: 123.0.6312.58
    Edge: 122.0.2365.92
    Safari: 17.4
  npmPackages:
    vitest: ^1.4.0 => 1.4.0

Used Package Manager

yarn

Validations

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• Read the Contributing Guidelines.
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[roryschadler]

Related: vitest-dev/vscode#308, #5408

cc @sheremet-va