Vite Build include unused variable(s)

[yuan116]

Describe the bug

Vite Build include unused variable(s) when the components are short circuit evaluation

src/Layout/LeftSidebar.jsx has a variable declare as array and map into Link component from react-router-dom
the src/Layout/LeftSidebar.jsx is imported in src/Layout/Header.jsx
while src/Layout/Header.jsxis imported and short circuit evaluated in src/Layout/index.jsx

Actual output:
Variables declare in src/Layout/LeftSidebar.jsx included in output

Expected output:
Variables declare in src/Layout/LeftSidebar.jsx or any components that short circuit evaluated (false) should not included in output

Reproduction

https://stackblitz.com/edit/vitejs-vite-rjt1ta?file=src%2Fpages%2FLayout%2FLeftSidebar.jsx

Steps to reproduce

Run npm run build

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (2) 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: 8.15.3 - /usr/local/bin/pnpm
npmPackages:
    @vitejs/plugin-react-swc: ^3.6.0 => 3.6.0 
    vite: ^5.2.6 => 5.2.7

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-rjt1ta (Open reproduction)

[sapphi-red]

The statement is included in the output because it has a sideeffect. That code accesses a global variable props and ref that might not be declared. Accessing a non-declared variable causes a ReferenceError.

Closing as this is an expected behavior.

[yuan116]

Hi @sapphi-red , sorry
I have updated the code based on the issue I mentioned

Code change:

1. Remove {...props} and ref
2. Change ['link-1', 'link-2', 'link-3'] to [{ text: 'link-1', to: 'link-a' },{ text: 'link-2', to: 'link-b' },{ text: 'link-3', to: 'link-c' },]

Could you check again?

[sapphi-red]

That is expected as well because property access is assumed to have sideeffects.
See rollup/rollup#5421 for more details.