refactor(css/parser): Remove value normalization (#8434)

**Related issue :**

 - https://linear.app/vercel/issue/PACK-2154

Author: kdy1

crates/swc_css_ast/src/base.rs

@@ -137,6 +137,15 @@ impl PartialEq<JsWord> for FunctionName {
     }
 }
 
+impl FunctionName {
+    pub fn as_str(&self) -> &str {
+        match self {
+            FunctionName::DashedIdent(v) => &v.value,
+            FunctionName::Ident(v) => &v.value,
+        }
+    }
+}
+
 #[ast_node("Function")]
 #[derive(Eq, Hash, EqIgnoreSpan)]
 pub struct Function {

crates/swc_css_codegen/tests/fixture.rs

@@ -11,7 +11,7 @@ use swc_css_codegen::{
 };
 use swc_css_parser::parse_file;
 use swc_css_visit::{VisitMut, VisitMutWith};
-use testing::{assert_eq, run_test2, NormalizedOutput};
+use testing::{run_test2, NormalizedOutput};
 
 fn run(input: &Path, minify: bool) {
     let dir = input.parent().unwrap();
@@ -80,6 +80,12 @@ fn run(input: &Path, minify: bool) {
             .compare_to_file(output)
             .unwrap();
 
+        if minify {
+            // We lowercase identifiers to make gzip compression rate better, so we cannot
+            // make the output equal to the input
+            return Ok(());
+        }
+
         let mut errors = vec![];
         let mut stylesheet_output: Stylesheet =
             parse_file(&fm_output, None, Default::default(), &mut errors).map_err(|err| {