<===> options.yml
---
:todo:
- libsass

<===> input.scss
.test {
  a01: (#{a}+5.0% + 2);
  a02: (#{a}+ 5.0% + 2);
  a03: (#{a}  +5.0% + 2);
  a04: (#{a} +  5.0% + 2);
  b01: (5 + 2.0%+#{a});
  b02: (5 + 2.0%+ #{a});
  b03: (5 + 2.0%  +#{a});
  b04: (5 + 2.0% +  #{a});
  c01: (#{a} +5.0% + 2);
  c02: (#{a} -5.0% + 2);
  c03: (#{a} /5.0% + 2);
  c04: (#{a} *5.0% + 2);
  c05: (#{a} +5.0% - 2);
  c06: (#{a} -5.0% - 2);
  c07: (#{a} /5.0% - 2);
  c08: (#{a} *5.0% - 2);
  c09: (#{a} +5.0% / 2);
  c10: (#{a} -5.0% / 2);
  c11: (#{a} /5.0% / 2);
  c12: (#{a} *5.0% / 2);
  c13: (#{a} +5.0% * 2);
  c14: (#{a} -5.0% * 2);
  c15: (#{a} /5.0% * 2);
  c16: (#{a} *5.0% * 2);
  d01: (5 + 2.0% +#{a});
  d02: (5 + 2.0% -#{a});
  d03: (5 + 2.0% /#{a});
  d04: (5 + 2.0% *#{a});
  d05: (5 - 2.0% +#{a});
  d06: (5 - 2.0% -#{a});
  d07: (5 - 2.0% /#{a});
  d08: (5 - 2.0% *#{a});
  d09: (5% / 2.0 +#{a});
  d10: (5% / 2.0 -#{a});
  d11: (5% / 2.0 /#{a});
  d12: (5% / 2.0 *#{a});
  d13: (5 * 2.0% +#{a});
  d14: (5 * 2.0% -#{a});
  d15: (5 * 2.0% /#{a});
  d16: (5 * 2.0% *#{a});
  e01: (#{a} ==5.0% == 2);
  e02: (#{a} >5.0% > 2);
  e03: (#{a} <5.0% < 2);
  e04: (#{a} >=5.0% >= 2);
  e05: (#{a} <=5.0% <= 2);
  e06: (#{a} !=5.0% != 2);
}

<===> error
Error: Undefined operation: "a times 5%".

<===> error-dart-sass
Error: Undefined operation "a * 5%".
   ,
13 |   c04: (#{a} *5.0% + 2);
   |         ^^^^^^^^^^
   '
  input.scss 13:9  root stylesheet