For the following input,

.foo {
  :where(& > .bar) {
    color: red;
  }
}

esbuild outputs

.foo{:where(>.bar){color:red}}

(esbuild try).

But this output is invalid because :where does not allow relative selectors.

Original issue: vitejs/vite#18974

reference

• :where() spec
• :is() spec: :is() has the same syntax with :where()
  • it takes <forgiving-selector-list> and not <forgiving-relative-selector-list>