Reactive forms pass spreads through instead of wrapping in fragments

adapter-dom.sx: if/when/cond reactive paths now check whether
initial-result is a spread. If so, return it directly — spreads
aren't DOM nodes and can't be appended to fragments. This lets
any spread-returning component (like ~cssx/tw) work inside islands
without the spread being silently dropped.

cssx.sx: revert make-spread workaround — the root cause is now
fixed in the adapter. ~cssx/tw can use a natural top-level if.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/static/scripts/sx-browser.js

@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-13T04:16:14Z";
+  var SX_VERSION = "2026-03-13T04:50:39Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -2019,7 +2019,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
 })();
   return (isSxTruthy(domParent(marker)) ? (forEach(function(n) { return domRemove(n); }, currentNodes), (currentNodes = (isSxTruthy(domIsFragment(result)) ? domChildNodes(result) : [result])), domInsertAfter(marker, result)) : (initialResult = result));
 })(); });
-  return (function() {
+  return (isSxTruthy(isSpread(initialResult)) ? initialResult : (function() {
   var frag = createFragment();
   domAppend(frag, marker);
   if (isSxTruthy(initialResult)) {
@@ -2027,7 +2027,7 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   domAppend(frag, initialResult);
 }
   return frag;
-})();
+})());
 })() : (function() {
   var condVal = trampoline(evalExpr(nth(expr, 1), env));
   return (isSxTruthy(condVal) ? renderToDom(nth(expr, 2), env, ns) : (isSxTruthy((len(expr) > 3)) ? renderToDom(nth(expr, 3), env, ns) : createFragment()));
@@ -2046,14 +2046,14 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   currentNodes = domChildNodes(frag);
   return (initialResult = frag);
 })() : NIL)); });
-  return (function() {
+  return (isSxTruthy(isSpread(initialResult)) ? initialResult : (function() {
   var frag = createFragment();
   domAppend(frag, marker);
   if (isSxTruthy(initialResult)) {
   domAppend(frag, initialResult);
 }
   return frag;
-})();
+})());
 })() : (isSxTruthy(!isSxTruthy(trampoline(evalExpr(nth(expr, 1), env)))) ? createFragment() : (function() {
   var frag = createFragment();
   { var _c = range(2, len(expr)); for (var _i = 0; _i < _c.length; _i++) { var i = _c[_i]; domAppend(frag, renderToDom(nth(expr, i), env, ns)); } }
@@ -2074,14 +2074,14 @@ return (function() { var _m = typeOf(expr); if (_m == "nil") return createFragme
   return (initialResult = result);
 })() : NIL));
 })(); });
-  return (function() {
+  return (isSxTruthy(isSpread(initialResult)) ? initialResult : (function() {
   var frag = createFragment();
   domAppend(frag, marker);
   if (isSxTruthy(initialResult)) {
   domAppend(frag, initialResult);
 }
   return frag;
-})();
+})());
 })() : (function() {
   var branch = evalCond(rest(expr), env);
   return (isSxTruthy(branch) ? renderToDom(branch, env, ns) : createFragment());

shared/sx/ref/adapter-dom.sx

@@ -406,16 +406,19 @@
                     (dom-insert-after marker result))
                   ;; Marker not yet in DOM (first run) — just save result
                   (set! initial-result result)))))
-            ;; Return fragment: marker + initial render result
+            ;; Spread pass-through: spreads aren't DOM nodes, can't live
-            (let ((frag (create-fragment)))
+            ;; in fragments. Return directly so parent element merges attrs.
-              (dom-append frag marker)
+            (if (spread? initial-result)
-              (when initial-result
+              initial-result
-                (set! current-nodes
+              (let ((frag (create-fragment)))
-                  (if (dom-is-fragment? initial-result)
+                (dom-append frag marker)
-                    (dom-child-nodes initial-result)
+                (when initial-result
-                    (list initial-result)))
+                  (set! current-nodes
-                (dom-append frag initial-result))
+                    (if (dom-is-fragment? initial-result)
-              frag))
+                      (dom-child-nodes initial-result)
+                      (list initial-result)))
+                  (dom-append frag initial-result))
+                frag)))
           ;; Static if
           (let ((cond-val (trampoline (eval-expr (nth expr 1) env))))
             (if cond-val
@@ -453,10 +456,13 @@
                       (range 2 (len expr)))
                     (set! current-nodes (dom-child-nodes frag))
                     (set! initial-result frag))))))
-            (let ((frag (create-fragment)))
+            ;; Spread pass-through
-              (dom-append frag marker)
+            (if (spread? initial-result)
-              (when initial-result (dom-append frag initial-result))
+              initial-result
-              frag))
+              (let ((frag (create-fragment)))
+                (dom-append frag marker)
+                (when initial-result (dom-append frag initial-result))
+                frag)))
           ;; Static when
           (if (not (trampoline (eval-expr (nth expr 1) env)))
             (create-fragment)
@@ -495,10 +501,13 @@
                           (dom-child-nodes result)
                           (list result)))
                       (set! initial-result result)))))))
-            (let ((frag (create-fragment)))
+            ;; Spread pass-through
-              (dom-append frag marker)
+            (if (spread? initial-result)
-              (when initial-result (dom-append frag initial-result))
+              initial-result
-              frag))
+              (let ((frag (create-fragment)))
+                (dom-append frag marker)
+                (when initial-result (dom-append frag initial-result))
+                frag)))
           ;; Static cond
           (let ((branch (eval-cond (rest expr) env)))
             (if branch

shared/sx/templates/cssx.sx

@@ -476,12 +476,10 @@
         (classes (map (fn (r) (get r "cls")) valid))
         (rules (map (fn (r) (get r "rule")) valid))
         (_ (for-each (fn (rule) (collect! "cssx" rule)) rules)))
-    ;; Return spread: injects class + data-tw onto parent element.
+    ;; Return spread: injects class + data-tw onto parent element
-    ;; The if is inside make-spread's arg so it goes through eval-expr
+    (if (empty? classes)
-    ;; (not render-to-dom), avoiding reactive-if wrapping in islands.
+      nil
-    (make-spread (if (empty? classes)
+      (make-spread {"class" (join " " classes)
-                   {}
-                   {"class" (join " " classes)
                     "data-tw" (or tokens "")}))))