fix: match HTML5 unquoted attributes terminators

Author: Princesseuh

crates/oxc_parser/src/astro/jsx.rs

@@ -688,11 +688,13 @@ impl<'a, C: ParserConfig> ParserImpl<'a, C> {
         while matches!(bytes.get(value_start), Some(b' ' | b'\t' | b'\r' | b'\n')) {
             value_start += 1;
         }
-        // A structural terminator (`/`, `>`, `}`, EOF) means the value is missing
-        // (`attr=` before `/>`); fall through to the JS path to report it there.
+        // A structural terminator (`>`, `}`, EOF) means the value is missing
+        // (`attr=` before `>`); fall through to the JS path to report it there.
+        // `/` is a valid first value char (HTML5): `href=/about` is value `/about`,
+        // and even `attr=/>` is value `/`, not a self-close.
         let is_unquoted = bytes
             .get(value_start)
-            .is_some_and(|b| !matches!(b, b'"' | b'\'' | b'{' | b'`' | b'<' | b'/' | b'>' | b'}'));
+            .is_some_and(|b| !matches!(b, b'"' | b'\'' | b'{' | b'`' | b'<' | b'>' | b'}'));
 
         if is_unquoted {
             self.prev_token_end = self.cur_token().end(); // consume `=`

crates/oxc_parser/src/lexer/astro.rs

@@ -43,12 +43,17 @@ mod astro_jsx {
         b'=' | b'>' | b'/' | b'{' | b'}' | b' ' | b'\t' | b'\n' | b'\r' | b'<'
     ));
 
-    /// Per HTML spec, unquoted attribute values cannot contain whitespace, `"`,
-    /// `'`, `=`, `<`, `>`, or backtick. We additionally stop at `/`, `{`, and
-    /// `}` so JSX self-closing tags and Astro expressions remain parseable.
+    /// An unquoted attribute value ends only at HTML5's terminators — whitespace
+    /// or `>` — plus the Astro-structural characters `{`/`}` (an expression
+    /// starts/ends) and `<` (a following tag). Everything else is an ordinary
+    /// value character, matching the HTML tokenizer, which flags `"`, `'`, `=`,
+    /// and backtick as a parse error but still appends them. So `href=a=b` and
+    /// `href=https://example.com/x` parse whole; the printer escapes any quotes
+    /// or backticks when emitting the value. The `/` self-close form
+    /// (`<img src=x />`) still works because the space ends the value first.
     static ASTRO_UNQUOTED_ATTR_VALUE_END_TABLE: SafeByteMatchTable = safe_byte_match_table!(|b| matches!(
         b,
-        b'=' | b'>' | b'/' | b'{' | b'}' | b' ' | b'\t' | b'\n' | b'\r' | b'<' | b'"' | b'\'' | b'`'
+        b'>' | b'{' | b'}' | b' ' | b'\t' | b'\n' | b'\r' | b'<'
     ));
 
     /// Astro/HTML text content can include `>` as literal text (unlike JSX).