HS Bucket F: array literal arg to JS fn fix (+1 test)

Generator emit_eval translates arr.reduce/map/filter to SX primitives
so SX list args work. host-call-fn sxToJs converts SX lists to native
JS arrays for native JS function calls. Fixes functionCalls
"can pass an array literal as an argument".

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

spec/tests/test-hyperscript-behavioral.sx

@@ -5315,7 +5315,7 @@
   (deftest "can invoke global function w/ async arg"
     (error "SKIP (untranslated): can invoke global function w/ async arg"))
   (deftest "can pass an array literal as an argument"
-    (assert= (eval-hs-locals "sum([1, 2, 3, 4])" (list (list (quote sum) (fn (arr) (host-call arr "reduce" (fn (a b) (+ a b)) 0))))) 10)
+    (assert= (eval-hs-locals "sum([1, 2, 3, 4])" (list (list (quote sum) (fn (arr) (reduce (fn (a b) (+ a b)) 0 arr))))) 10)
   )
   (deftest "can pass an expression as an argument"
     (assert= (eval-hs-locals "double(3 + 4)" (list (list (quote double) (fn (n) (* n 2))))) 14)

tests/hs-run-filtered.js

@@ -553,7 +553,7 @@ K.registerNative('host-get',a=>{
 });
 K.registerNative('host-set!',a=>{if(a[0]!=null){const v=a[2]; if(a[1]==='innerHTML'&&a[0] instanceof El){const s=v===null?'null':v===undefined?'':String(v);a[0]._setInnerHTML(s);a[0][a[1]]=a[0].innerHTML;} else if(a[1]==='textContent'&&a[0] instanceof El){const s=v===null?'null':v===undefined?'':String(v);a[0].textContent=s;a[0].innerHTML=s;for(const c of a[0].children){c.parentElement=null;c.parentNode=null;}a[0].children=[];a[0].childNodes=[];} else{a[0][a[1]]=v;}} return a[2];});
 K.registerNative('host-call',a=>{if(_testDeadline&&Date.now()>_testDeadline)throw new Error('TIMEOUT: wall clock exceeded');const[o,m,...r]=a;if(o==null){const f=globalThis[m];return typeof f==='function'?f.apply(null,r):null;}if(o&&typeof o[m]==='function'){try{const v=o[m].apply(o,r);return v===undefined?null:v;}catch(e){return null;}}return null;});
-K.registerNative('host-call-fn',a=>{const[fn,argList]=a;if(typeof fn!=='function'&&!(fn&&fn.__sx_handle!==undefined))return null;const callArgs=(argList&&argList._type==='list'&&argList.items)?Array.from(argList.items):(Array.isArray(argList)?argList:[]);if(fn&&fn.__sx_handle!==undefined)return K.callFn(fn,callArgs);try{const v=fn.apply(null,callArgs);return v===undefined?null:v;}catch(e){return null;}});
+K.registerNative('host-call-fn',a=>{const[fn,argList]=a;if(typeof fn!=='function'&&!(fn&&fn.__sx_handle!==undefined))return null;const callArgs=(argList&&argList._type==='list'&&argList.items)?Array.from(argList.items):(Array.isArray(argList)?argList:[]);if(fn&&fn.__sx_handle!==undefined)return K.callFn(fn,callArgs);function sxToJs(v){if(v&&v._type==='list'&&v.items)return Array.from(v.items).map(sxToJs);return v;}try{const v=fn.apply(null,callArgs.map(sxToJs));return v===undefined?null:v;}catch(e){return null;}});
 K.registerNative('host-new',a=>{const C=typeof a[0]==='string'?globalThis[a[0]]:a[0];return typeof C==='function'?new C(...a.slice(1)):null;});
 K.registerNative('host-callback',a=>{const fn=a[0];if(typeof fn==='function'&&fn.__sx_handle===undefined)return fn;if(fn&&fn.__sx_handle!==undefined)return function(){const r=K.callFn(fn,Array.from(arguments));if(globalThis._driveAsync)globalThis._driveAsync(r);return r;};return function(){};});
 K.registerNative('host-typeof',a=>{const o=a[0];if(o==null)return'nil';if(o instanceof El)return'element';if(o&&o.nodeType===3)return'text';if(o instanceof Ev)return'event';if(o instanceof Promise)return'promise';return typeof o;});

tests/playwright/generate-sx-tests.py

@@ -1666,6 +1666,13 @@ def js_expr_to_sx(expr):
             if s is None:
                 return None
             arg_sx.append(s)
+        # Translate common array HO methods to SX primitives so SX lists work.
+        if method == 'reduce' and len(arg_sx) == 2:
+            return f'(reduce {arg_sx[0]} {arg_sx[1]} {obj})'
+        if method == 'map' and len(arg_sx) == 1:
+            return f'(map {arg_sx[0]} {obj})'
+        if method == 'filter' and len(arg_sx) == 1:
+            return f'(filter {arg_sx[0]} {obj})'
         return f'(host-call {obj} "{method}" {" ".join(arg_sx)})'.strip()
 
     # Property access: o.prop