Macro assert_semantic_eq 

macro_rules! assert_semantic_eq {
    ($atomset: path, $ty: ty, $a: literal, $b: literal) => { ... };
}

(Requires feature “testing”) Given a Node and two strings, this will expand to code that sets up a parser, parses both strings as the given Node from a single source text, and asserts that the two parsed Nodes are equal according to SemanticEq. If either parse fails, or the nodes are not semantically equal, this macro will panic with a readable failure.

use css_parse::*;
assert_semantic_eq!(EmptyAtomSet::ATOMS, T![Ident], "foo", "FoO");