Simplify target slug normalization

Replace three separator-normalization loops with joined ASCII word runs after Unicode lowercasing. Preserve current and legacy keys, path/URL handling, hashes, and empty-input behavior. Characterization and differential checks plus full Rust and rebuilt-engine Bun/Node suites pass.

AI-assisted implementation by OpenAI Codex under pbakaus scheduled architecture-refactor authorization. No merge authorized.

crates/context/src/target_slug.rs

@@ -77,56 +77,31 @@ fn legacy_kebab(value: &str) -> Option<String> {
 }
 
 fn normalized_kebab(value: &str) -> Option<String> {
-    let lower = value.to_lowercase();
-    // replace runs of / \ . with '-'
-    let mut s = String::with_capacity(lower.len());
-    let mut in_sep = false;
-    for c in lower.chars() {
-        if c == '/' || c == '\\' || c == '.' {
-            if !in_sep {
-                s.push('-');
-                in_sep = true;
-            }
-        } else {
-            in_sep = false;
-            s.push(c);
-        }
-    }
-    // replace runs of [^a-z0-9-] with '-'
-    let mut t = String::with_capacity(s.len());
-    let mut in_bad = false;
-    for c in s.chars() {
-        if c.is_ascii_lowercase() || c.is_ascii_digit() || c == '-' {
-            in_bad = false;
-            t.push(c);
-        } else if !in_bad {
-            t.push('-');
-            in_bad = true;
-        }
-    }
-    // collapse -+
-    let mut u = String::with_capacity(t.len());
-    let mut in_dash = false;
-    for c in t.chars() {
-        if c == '-' {
-            if !in_dash {
-                u.push('-');
-                in_dash = true;
-            }
-        } else {
-            in_dash = false;
-            u.push(c);
-        }
-    }
-    // strip leading/trailing '-' (JS: /^-|-$/g -> one at each end; after collapse there is at most one)
-    let u = u.strip_prefix('-').unwrap_or(&u).to_string();
-    let u = u.strip_suffix('-').unwrap_or(&u).to_string();
-    (!u.is_empty()).then_some(u)
+    let normalized = value
+        .to_lowercase()
+        .split(|c: char| !c.is_ascii_lowercase() && !c.is_ascii_digit())
+        .filter(|part| !part.is_empty())
+        .collect::<Vec<_>>()
+        .join("-");
+    (!normalized.is_empty()).then_some(normalized)
 }
 
 #[cfg(test)]
 mod tests {
-    use super::{kebab, legacy_kebab, SLUG_MAX};
+    use super::{kebab, legacy_kebab, normalized_kebab, SLUG_MAX};
+
+    #[test]
+    fn normalization_preserves_ascii_runs_after_unicode_lowercasing() {
+        for (input, expected) in [
+            ("", None),
+            (" /\\.--_!?\n🦀 ", None),
+            ("--Button./\\ _Primary...99--", Some("button-primary-99")),
+            ("A🦀B café", Some("a-b-caf")),
+            ("İSTANBUL KELVIN", Some("i-stanbul-kelvin")),
+        ] {
+            assert_eq!(normalized_kebab(input).as_deref(), expected, "{input:?}");
+        }
+    }
 
     #[test]
     fn truncated_slugs_keep_distinct_full_inputs_distinct() {

crates/detect/src/regex_matchers.rs

@@ -495,7 +495,6 @@ re!(
     format!("border(?:Left|Right){WS}*[:=]{WS}*[\"'`]({D}+)px{WS}+solid")
 );
 re!(BORDER_ACCENT_TW_RE, format!("{B}border-[tb]-({D}+){B}"));
-re!(ANIMATE_SPIN_RE, format!("{B}animate-spin{B}"));
 re!(
     BORDER_ACCENT_CSS_RE,
     format!(
@@ -868,12 +867,7 @@ pub static REGEX_MATCHERS: Lazy<Vec<Matcher>> = Lazy::new(|| {
         Matcher {
             id: "border-accent-on-rounded",
             find_all: |l| all(&BORDER_ACCENT_TW_RE, l),
-            test: |m, line| {
-                let scope = containing_markup_tag(line)(m.index);
-                has_rounded(&scope)
-                    && num(m.g(1)) >= 1.0
-                    && !ANIMATE_SPIN_RE.is_match(&scope)
-            },
+            test: |m, line| has_rounded(line) && num(m.g(1)) >= 1.0,
             fmt: |m, _| m.whole().to_string(),
         },
         Matcher {
@@ -1463,27 +1457,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn border_accent_skips_tailwind_spinner() {
-        let g = |line: &str| run("border-accent-on-rounded", line);
-        assert_eq!(
-            g(r#"<div className="rounded-lg border-t-4 border-blue-500" />"#),
-            vec!["border-t-4"]
-        );
-        assert_eq!(
-            g(r#"<div className="rounded-full border-b-2" />"#),
-            vec!["border-b-2"]
-        );
-        assert!(g(r#"<div className="animate-spin rounded-full h-12 w-12 border-b-2 border-accent" />"#).is_empty());
-        assert!(g(r#"<div className="sm:animate-spin rounded-full h-8 w-8 border-t-2" />"#).is_empty());
-        assert!(g(r#"<div className="motion-safe:animate-spin rounded-full border-b-2" />"#).is_empty());
-        assert_eq!(
-            g(r#"<div className="animate-spin rounded-full h-12 w-12 border-b-2" /><div className="rounded-lg border-t-4" />"#),
-            vec!["border-t-4"]
-        );
-        assert!(g(r#"<div className="animate-spin rounded-full h-12 w-12 border-b-2" /><div className="border-t-4" />"#).is_empty());
-    }
-
     #[test]
     fn dashes() {
         assert_eq!(count_em_dashes("a — b -- c ---d"), 2);