Vite wraps keys of objects in quotes when not necessary

[floratmin]

Describe the bug

I am having this object:

const ꁈꄼሕᣎᠳ勞 = {
    ꁈꄼሕᣎᠳ勞: 'test ',
    ฆ理ꃝꋹᕠ礼: 'bar'
};

when I build it this becomes:

const r={"ꁈꄼሕᣎᠳ勞":"test ",ฆ理ꃝꋹᕠ礼:"bar"};

With rollup the quotes are not added.

Reproduction

https://stackblitz.com/edit/vitejs-vite-wa7pdnu4?file=dist%2Fassets%2Findex-D-qYHHrO.js

Steps to reproduce

npm run build

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: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vite: ^6.0.3 => 6.0.3

Used Package Manager

npm

Logs

No response

Validations

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[sapphi-red]

It seems esbuild quotes ᣎ (U+18CE).
ID_Start category can be used as an identifier for ES2015+. U+18CE is in the Other Letter category which is included in ID_Start category. But this character was added in Unicode 5.2.

ES5 uses Unicode 3.0 (evanw/esbuild#1599) and ES2015 use Unicode 5.1 and ES2016 uses Unicode 8.0.0. So that character can only be used as an identifier for ES2016+.

I guess esbuild quotes the character for compat and does it regardless of the target because it's not worth much.

Closing as this is not a bug in Vite. If it's important for you, I recommend opening an issue in esbuild.