HS: as Date/Set/Map return real JS host objects (+4 tests)

- hs-coerce "Date": new case returns (host-new "Date" value)
- hs-coerce "Set": creates real JS Set via host-new + for-each add (was SX list)
- hs-coerce "Map": creates real JS Map via host-new + for-each set (was SX list)
- hs-make "Set"/"Map": use host-new instead of (list)/(dict)
- hs-add-to!, hs-remove-from!, hs-empty-like, hs-append: handle real JS Sets
- hs-run-filtered.js: add hs-is-set? and hs-is-map? natives
- generator: MANUAL_TEST_BODIES for converts-as-Date (×2), as-Set, as-Map
asExpression suite: 36/42 (was 32/42)

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

lib/hyperscript/runtime.sx

@@ -470,6 +470,7 @@
           (some (fn (x) (= x value)) target)
           target
           (append target (list value))))
+      ((hs-is-set? target) (do (host-call target "add" value) target))
       (true (do (host-call target "push" value) target)))))
 
 ;; ── Object creation ─────────────────────────────────────────────
@@ -480,10 +481,10 @@
   hs-remove-from!
   (fn
     (value target)
-    (if
-      (list? target)
-      (filter (fn (x) (not (= x value))) target)
-      (host-call target "splice" (host-call target "indexOf" value) 1))))
+    (cond
+      ((list? target) (filter (fn (x) (not (= x value))) target))
+      ((hs-is-set? target) (do (host-call target "delete" value) target))
+      (true (host-call target "splice" (host-call target "indexOf" value) 1)))))
 
 ;; ── Behavior installation ───────────────────────────────────────
 
@@ -965,6 +966,7 @@
             (some (fn (x) (= x value)) target)
             target
             (append target (list value))))
+        ((hs-is-set? target) (do (host-call target "add" value) target))
         ((hs-element? target)
           (do
             (dom-insert-adjacent-html
@@ -1260,22 +1262,24 @@
             value)
           value))
       ((= type-name "Set")
-        (if
-          (list? value)
-          (reduce
-            (fn
-              (acc x)
-              (if (some (fn (a) (= a x)) acc) acc (append acc (list x))))
-            (list)
-            value)
-          value))
+        (let
+          ((s (host-new "Set")))
+          (do
+            (when
+              (list? value)
+              (for-each (fn (x) (host-call s "add" x)) value))
+            s)))
       ((= type-name "Map")
-        (if
-          (dict? value)
-          (let
-            ((ks (if (dict-has? value "_order") (get value "_order") (filter (fn (k) (not (= k "_order"))) (keys value)))))
-            (map (fn (k) (list k (get value k))) ks))
-          value))
+        (let
+          ((m (host-new "Map")))
+          (do
+            (when
+              (dict? value)
+              (for-each
+                (fn (k) (host-call m "set" k (get value k)))
+                (filter (fn (k) (not (= k "_order"))) (keys value))))
+            m)))
+      ((= type-name "Date") (host-new "Date" value))
       (true value))))
 
 (define
@@ -1471,8 +1475,8 @@
             (cond
               ((= type-name "Object") (dict))
               ((= type-name "Array") (list))
-              ((= type-name "Set") (list))
-              ((= type-name "Map") (dict))
+              ((= type-name "Set") (host-new "Set"))
+              ((= type-name "Map") (host-new "Map"))
               (true (dict)))
             (apply host-new (cons type-name args)))))))
   (define
@@ -1871,6 +1875,8 @@
     (cond
       ((list? v) (list))
       ((dict? v) (dict))
+      ((hs-is-set? v) (host-new "Set"))
+      ((hs-is-map? v) (host-new "Map"))
       ((string? v) "")
       ((nil? v) nil)
       (true v))))

spec/tests/test-hyperscript-behavioral.sx

@@ -3724,7 +3724,9 @@
   (deftest "can accept custom dynamic conversions"
     (error "SKIP (untranslated): can accept custom dynamic conversions"))
   (deftest "can use the a modifier if you like"
-    (error "SKIP (untranslated): can use the a modifier if you like"))
+    (let ((_result (eval-hs "1 as a Date")))
+      (assert= (host-call _result "getTime") 1))
+  )
   (deftest "can use the an modifier if you'd like"
     (assert= (host-get (eval-hs "'{\"foo\":\"bar\"}' as an Object") "foo") "bar")
   )
@@ -3828,7 +3830,10 @@
     (assert= (eval-hs "[1,2,3] as Reversed") (list 3 2 1))
   )
   (deftest "converts array as Set"
-    (error "SKIP (untranslated): converts array as Set"))
+    (let ((_result (eval-hs "[1,2,2,3] as Set")))
+      (assert (hs-is-set? _result))
+      (assert= (host-get _result "size") 3))
+  )
   (deftest "converts array as Unique"
     (assert= (eval-hs "[1,2,2,3,3] as Unique") (list 1 2 3))
   )
@@ -3881,7 +3886,11 @@
     (assert= (eval-hs "{a:1, b:2} as Keys") (list "a" "b"))
   )
   (deftest "converts object as Map"
-    (error "SKIP (untranslated): converts object as Map"))
+    (let ((_result (eval-hs "{a:1, b:2} as Map")))
+      (assert (hs-is-map? _result))
+      (assert= (host-call _result "get" "a") 1)
+      (assert= (host-get _result "size") 2))
+  )
   (deftest "converts radio buttons into a Value correctly"
     (let ((_node (dom-create-element "form")))
       (dom-set-inner-html _node "<div> <input type=\"radio\" name=\"gender\" value=\"Male\" checked> <input type=\"radio\" name=\"gender\" value=\"Female\"> <input type=\"radio\" name=\"gender\" value=\"Other\"> </div>")
@@ -3901,7 +3910,9 @@
     (assert= (eval-hs "'hello' as Boolean") true)
   )
   (deftest "converts value as Date"
-    (error "SKIP (untranslated): converts value as Date"))
+    (let ((_result (eval-hs "1 as Date")))
+      (assert= (host-call _result "getTime") 1))
+  )
   (deftest "converts value as Fixed"
     (assert= (eval-hs "'10.4' as Fixed") "10")
     (assert= (eval-hs "'10.4899' as Fixed:2") "10.49")

tests/hs-run-filtered.js

@@ -593,6 +593,8 @@ K.registerNative('host-iter?',([obj])=>obj!=null&&typeof obj[Symbol.iterator]===
 K.registerNative('host-to-list',([obj])=>{try{return[...obj];}catch(e){return[];}});
 K.registerNative('host-await',a=>{});
 K.registerNative('load-library!',()=>false);
+K.registerNative('hs-is-set?',a=>a[0] instanceof Set);
+K.registerNative('hs-is-map?',a=>a[0] instanceof Map);
 // Upstream test fixtures: synchronous stubs matching OCaml run_tests.ml registrations
 globalThis.promiseAString = () => 'foo';
 globalThis.promiseAnInt = () => 42;

tests/playwright/generate-sx-tests.py

@@ -326,6 +326,26 @@ MANUAL_TEST_BODIES = {
         '          (list (list (quote record) record)))',
         '        "<div age=\\"21\\" style=\\"color:bleaux\\">John Connor</div>"))',
     ],
+    # asExpression: Date/Set/Map need real JS host objects
+    "converts value as Date": [
+        '    (let ((_result (eval-hs "1 as Date")))',
+        '      (assert= (host-call _result "getTime") 1))',
+    ],
+    "can use the a modifier if you like": [
+        '    (let ((_result (eval-hs "1 as a Date")))',
+        '      (assert= (host-call _result "getTime") 1))',
+    ],
+    "converts array as Set": [
+        '    (let ((_result (eval-hs "[1,2,2,3] as Set")))',
+        '      (assert (hs-is-set? _result))',
+        '      (assert= (host-get _result "size") 3))',
+    ],
+    "converts object as Map": [
+        '    (let ((_result (eval-hs "{a:1, b:2} as Map")))',
+        '      (assert (hs-is-map? _result))',
+        '      (assert= (host-call _result "get" "a") 1)',
+        '      (assert= (host-get _result "size") 2))',
+    ],
 }