<===> input.scss
@function element() {
  @return null;
}

<===> error-dart-sass
Error: Invalid function name.
  ,
1 | @function element() {
  | ^^^^^^^^^^^^^^^^^^^
  '
  input.scss 1:1  root stylesheet

<===> output.css
<===> warning
DEPRECATION WARNING on line 1 of /sass/spec/libsass-issues/issue_1681/element/input.scss:
Naming a function "element" is disallowed and will be an error in future versions of Sass.
This name conflicts with an existing CSS function with special parse rules.