HS E36: socket URL parsing + hs-socket-register! runtime (+3 tests)

- parser.sx: parse-socket-feat handles /path and scheme:// URLs; collect-url
  greedily joins URL continuation tokens (ident/number/op/colon/dot)
- tokenizer.sx: fix :// not treated as line comment (lookback check)
- compiler.sx: emit-socket compiles socket AST to hs-socket-register! call
- runtime.sx: hs-socket-register! normalises URL (relative→ws:/wss:),
  constructs WebSocket, builds wrapper dict, binds on window name-path
- hs-run-filtered.js: WebSocket mock uses plain object (not JS array) so
  host-global returns a foreign value rather than SX list; host-get idx works

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

lib/hyperscript/compiler.sx

@@ -787,6 +787,31 @@
               (quote fn)
               (cons (quote me) (map make-symbol params))
               (cons (quote do) (map hs-to-sx body)))))))
+    (define
+      emit-socket
+      (fn
+        (ast)
+        (let
+          ((name-path (nth ast 1))
+           (url (nth ast 2))
+           (timeout-ms (nth ast 3))
+           (on-msg (nth ast 4)))
+         (let
+           ((handler
+             (if
+               (nil? on-msg)
+               nil
+               (let
+                 ((body (hs-to-sx (nth on-msg 2))))
+                 (list (quote fn) (list (quote event)) body))))
+             (json?-val (if (nil? on-msg) false (nth on-msg 1))))
+           (list
+             (quote hs-socket-register!)
+             (cons (quote list) name-path)
+             url
+             (if (nil? timeout-ms) nil (hs-to-sx timeout-ms))
+             handler
+             json?-val)))))
     (fn
       (ast)
       (cond
@@ -2075,6 +2100,7 @@
                           (quote _hs-def-val))
                         (quote _hs-def-val))))))
               ((= head (quote behavior)) (emit-behavior ast))
+              ((= head (quote socket)) (emit-socket ast))
               ((= head (quote sx-eval))
                 (let
                   ((src (nth ast 1)))

lib/hyperscript/parser.sx

@@ -2733,7 +2733,6 @@
         parse-socket-feat
         (fn
           ()
-          ;; Collect name-path: ident (class)* → e.g. ["Foo"] or ["MyApp" "chat"]
           (let
             ((seg0 (tp-val)))
             (adv!)
@@ -2750,7 +2749,6 @@
                   acc)))
             (let
               ((name-path (collect-segs (list seg0))))
-              ;; url-cont?: token types that can appear inside a URL
               (define
                 url-cont?
                 (fn
@@ -2769,7 +2767,6 @@
                           (= (tp-val) "with")
                           (= (tp-val) "on")
                           (= (tp-val) "as")))))))
-              ;; collect-url: accumulate URL tokens into a joined string
               (define
                 collect-url
                 (fn
@@ -2781,51 +2778,12 @@
                       (adv!)
                       (collect-url (append parts (list v))))
                     (join "" parts))))
-              ;; Parse URL: /path, scheme://..., string literal, or expression
               (let
-                ((url
-                  (cond
-                    ;; Relative path starting with /
-                    ((and (= (tp-type) "op") (= (tp-val) "/"))
-                      (adv!)
-                      (collect-url (list "/")))
-                    ;; Absolute URL: ident + colon → collect as scheme:rest
-                    ((= (tp-type) "ident")
-                      (let
-                        ((scheme (tp-val)))
-                        (adv!)
-                        (if
-                          (= (tp-type) "colon")
-                          (collect-url (list scheme))
-                          (parse-arith (parse-poss (list (quote ref) scheme))))))
-                    ;; String literal or other expression
-                    (true (parse-atom)))))
-                ;; Optional: with timeout <expr>
+                ((url (cond ((and (= (tp-type) "op") (= (tp-val) "/")) (do (adv!) (collect-url (list "/")))) ((= (tp-type) "ident") (let ((scheme (tp-val))) (adv!) (if (= (tp-type) "colon") (collect-url (list scheme)) (parse-arith (parse-poss (list (quote ref) scheme)))))) (true (parse-atom)))))
                 (let
-                  ((timeout-ms
-                    (if
-                      (match-kw "with")
-                      (do
-                        (adv!)
-                        (parse-expr))
-                      nil)))
-                  ;; Optional: on message [as JSON] <cmd-list>
+                  ((timeout-ms (if (match-kw "with") (do (adv!) (parse-expr)) nil)))
                   (let
-                    ((on-msg
-                      (if
-                        (match-kw "on")
-                        (do
-                          (adv!)
-                          (let
-                            ((json?
-                              (if
-                                (match-kw "as")
-                                (do (adv!) true)
-                                false)))
-                            (let
-                              ((body (parse-cmd-list)))
-                              (list (quote on-message) json? body))))
-                        nil)))
+                    ((on-msg (if (match-kw "on") (do (adv!) (let ((json? (if (match-kw "as") (do (adv!) true) false))) (let ((body (parse-cmd-list))) (list (quote on-message) json? body)))) nil)))
                     (match-kw "end")
                     (list (quote socket) name-path url timeout-ms on-msg))))))))
       (define

lib/hyperscript/runtime.sx

@@ -2525,3 +2525,56 @@
   (fn
     (fn-name args)
     (let ((fn (host-global fn-name))) (if fn (host-call-fn fn args) nil))))
+
+;; ── WebSocket / socket feature ───────────────────────────────────
+
+(define
+  hs-socket-register!
+  (fn
+    (name-path url timeout-ms handler json?)
+    ;; 1. Normalise URL — absolute ws/wss pass through; relative paths get scheme+host
+    (let
+      ((ws-url
+        (cond
+          ((or (starts-with? url "ws://") (starts-with? url "wss://")) url)
+          (true
+            (let
+              ((proto (host-get (host-global "location") "protocol"))
+                (h (host-get (host-global "location") "host")))
+              (str (if (= proto "https:") "wss:" "ws:") "//" h url))))))
+      ;; 2. Construct WebSocket
+      (let
+        ((ws (host-new "WebSocket" ws-url)))
+        ;; 3. Build wrapper dict
+        (let
+          ((wrapper
+            {:raw ws
+             :url ws-url
+             :timeout timeout-ms
+             :pending {}
+             :handler handler
+             :json? json?
+             :closed? false}))
+          ;; 4. Wire RPC proxy via JS factory (if available)
+          (let
+            ((proxy-factory (host-global "_hs_make_rpc_proxy")))
+            (when proxy-factory
+              (host-set! wrapper "rpc"
+                (host-call proxy-factory "call" nil wrapper))))
+          ;; 5. Bind wrapper on window, walking name-path
+          (define
+            bind-path!
+            (fn
+              (obj path)
+              (if
+                (= (len path) 1)
+                (host-set! obj (first path) wrapper)
+                (let
+                  ((key (first path))
+                    (rest-path (rest path)))
+                  (let
+                    ((next (or (host-get obj key) {})))
+                    (host-set! obj key next)
+                    (bind-path! next rest-path))))))
+          (bind-path! (host-global "window") name-path)
+          wrapper)))))

lib/hyperscript/tokenizer.sx

@@ -441,7 +441,11 @@
               (cond
                 (and (= ch "-") (< (+ pos 1) src-len) (= (hs-peek 1) "-"))
                 (do (hs-advance! 2) (skip-comment!) (scan!))
-                (and (= ch "/") (< (+ pos 1) src-len) (= (hs-peek 1) "/"))
+                (and
+                  (= ch "/")
+                  (< (+ pos 1) src-len)
+                  (= (hs-peek 1) "/")
+                  (not (and (> pos 0) (= (hs-peek -1) ":"))))
                 (do (hs-advance! 2) (skip-comment!) (scan!))
                 (and
                   (= ch "<")

shared/static/wasm/sx/hs-compiler.sx

@@ -787,6 +787,31 @@
               (quote fn)
               (cons (quote me) (map make-symbol params))
               (cons (quote do) (map hs-to-sx body)))))))
+    (define
+      emit-socket
+      (fn
+        (ast)
+        (let
+          ((name-path (nth ast 1))
+           (url (nth ast 2))
+           (timeout-ms (nth ast 3))
+           (on-msg (nth ast 4)))
+         (let
+           ((handler
+             (if
+               (nil? on-msg)
+               nil
+               (let
+                 ((body (hs-to-sx (nth on-msg 2))))
+                 (list (quote fn) (list (quote event)) body))))
+             (json?-val (if (nil? on-msg) false (nth on-msg 1))))
+           (list
+             (quote hs-socket-register!)
+             (cons (quote list) name-path)
+             url
+             (if (nil? timeout-ms) nil (hs-to-sx timeout-ms))
+             handler
+             json?-val)))))
     (fn
       (ast)
       (cond
@@ -2075,6 +2100,7 @@
                           (quote _hs-def-val))
                         (quote _hs-def-val))))))
               ((= head (quote behavior)) (emit-behavior ast))
+              ((= head (quote socket)) (emit-socket ast))
               ((= head (quote sx-eval))
                 (let
                   ((src (nth ast 1)))

shared/static/wasm/sx/hs-parser.sx

@@ -2729,6 +2729,63 @@
                   (match-kw "end")
                   (list (quote when-feat-no-op)))))
             (do (pwf-skip) (match-kw "end") (list (quote when-feat-no-op))))))
+      (define
+        parse-socket-feat
+        (fn
+          ()
+          (let
+            ((seg0 (tp-val)))
+            (adv!)
+            (define
+              collect-segs
+              (fn
+                (acc)
+                (if
+                  (= (tp-type) "class")
+                  (let
+                    ((seg (tp-val)))
+                    (adv!)
+                    (collect-segs (append acc (list seg))))
+                  acc)))
+            (let
+              ((name-path (collect-segs (list seg0))))
+              (define
+                url-cont?
+                (fn
+                  ()
+                  (or
+                    (= (tp-type) "ident")
+                    (= (tp-type) "number")
+                    (= (tp-type) "op")
+                    (= (tp-type) "colon")
+                    (= (tp-type) "dot")
+                    (and
+                      (= (tp-type) "keyword")
+                      (not
+                        (or
+                          (= (tp-val) "end")
+                          (= (tp-val) "with")
+                          (= (tp-val) "on")
+                          (= (tp-val) "as")))))))
+              (define
+                collect-url
+                (fn
+                  (parts)
+                  (if
+                    (and (not (at-end?)) (url-cont?))
+                    (let
+                      ((v (tp-val)))
+                      (adv!)
+                      (collect-url (append parts (list v))))
+                    (join "" parts))))
+              (let
+                ((url (cond ((and (= (tp-type) "op") (= (tp-val) "/")) (do (adv!) (collect-url (list "/")))) ((= (tp-type) "ident") (let ((scheme (tp-val))) (adv!) (if (= (tp-type) "colon") (collect-url (list scheme)) (parse-arith (parse-poss (list (quote ref) scheme)))))) (true (parse-atom)))))
+                (let
+                  ((timeout-ms (if (match-kw "with") (do (adv!) (parse-expr)) nil)))
+                  (let
+                    ((on-msg (if (match-kw "on") (do (adv!) (let ((json? (if (match-kw "as") (do (adv!) true) false))) (let ((body (parse-cmd-list))) (list (quote on-message) json? body)))) nil)))
+                    (match-kw "end")
+                    (list (quote socket) name-path url timeout-ms on-msg))))))))
       (define
         parse-feat
         (fn
@@ -2749,6 +2806,7 @@
               ((= val "behavior") (do (adv!) (parse-behavior-feat)))
               ((= val "live") (do (adv!) (parse-live-feat)))
               ((= val "when") (do (adv!) (parse-when-feat)))
+              ((= val "socket") (do (adv!) (parse-socket-feat)))
               (true (parse-cmd-list))))))
       (define
         coll-feats

shared/static/wasm/sx/hs-runtime.sx

@@ -2525,3 +2525,56 @@
   (fn
     (fn-name args)
     (let ((fn (host-global fn-name))) (if fn (host-call-fn fn args) nil))))
+
+;; ── WebSocket / socket feature ───────────────────────────────────
+
+(define
+  hs-socket-register!
+  (fn
+    (name-path url timeout-ms handler json?)
+    ;; 1. Normalise URL — absolute ws/wss pass through; relative paths get scheme+host
+    (let
+      ((ws-url
+        (cond
+          ((or (starts-with? url "ws://") (starts-with? url "wss://")) url)
+          (true
+            (let
+              ((proto (host-get (host-global "location") "protocol"))
+                (h (host-get (host-global "location") "host")))
+              (str (if (= proto "https:") "wss:" "ws:") "//" h url))))))
+      ;; 2. Construct WebSocket
+      (let
+        ((ws (host-new "WebSocket" ws-url)))
+        ;; 3. Build wrapper dict
+        (let
+          ((wrapper
+            {:raw ws
+             :url ws-url
+             :timeout timeout-ms
+             :pending {}
+             :handler handler
+             :json? json?
+             :closed? false}))
+          ;; 4. Wire RPC proxy via JS factory (if available)
+          (let
+            ((proxy-factory (host-global "_hs_make_rpc_proxy")))
+            (when proxy-factory
+              (host-set! wrapper "rpc"
+                (host-call proxy-factory "call" nil wrapper))))
+          ;; 5. Bind wrapper on window, walking name-path
+          (define
+            bind-path!
+            (fn
+              (obj path)
+              (if
+                (= (len path) 1)
+                (host-set! obj (first path) wrapper)
+                (let
+                  ((key (first path))
+                    (rest-path (rest path)))
+                  (let
+                    ((next (or (host-get obj key) {})))
+                    (host-set! obj key next)
+                    (bind-path! next rest-path))))))
+          (bind-path! (host-global "window") name-path)
+          wrapper)))))

shared/static/wasm/sx/hs-tokenizer.sx

@@ -441,7 +441,11 @@
               (cond
                 (and (= ch "-") (< (+ pos 1) src-len) (= (hs-peek 1) "-"))
                 (do (hs-advance! 2) (skip-comment!) (scan!))
-                (and (= ch "/") (< (+ pos 1) src-len) (= (hs-peek 1) "/"))
+                (and
+                  (= ch "/")
+                  (< (+ pos 1) src-len)
+                  (= (hs-peek 1) "/")
+                  (not (and (> pos 0) (= (hs-peek -1) ":"))))
                 (do (hs-advance! 2) (skip-comment!) (scan!))
                 (and
                   (= ch "<")

spec/tests/test-hyperscript-behavioral.sx

@@ -11508,9 +11508,19 @@
 ;; ── socket (16 tests) ──
 (defsuite "hs-upstream-socket"
   (deftest "converts relative URL to ws:// on http pages"
-    (error "SKIP (untranslated): converts relative URL to ws:// on http pages"))
+    (hs-cleanup!)
+    (host-set! (host-global "window") "__hs_ws_created" (list))
+    (eval-hs "socket RelSocket /my-ws end")
+    (let ((sock (host-get (host-global "__hs_ws_created") 0)))
+      (assert= (host-get sock "url") "ws://localhost/my-ws")))
   (deftest "converts relative URL to wss:// on https pages"
-    (error "SKIP (untranslated): converts relative URL to wss:// on https pages"))
+    (hs-cleanup!)
+    (host-set! (host-global "window") "__hs_ws_created" (list))
+    (host-set! (host-global "location") "protocol" "https:")
+    (eval-hs "socket RelSocket /my-ws end")
+    (host-set! (host-global "location") "protocol" "http:")
+    (let ((sock (host-get (host-global "__hs_ws_created") 0)))
+      (assert= (host-get sock "url") "wss://localhost/my-ws")))
   (deftest "dispatchEvent sends JSON-encoded event over the socket"
     (error "SKIP (untranslated): dispatchEvent sends JSON-encoded event over the socket"))
   (deftest "namespaced sockets work"
@@ -11522,7 +11532,11 @@
   (deftest "on message handler fires on incoming text message"
     (error "SKIP (untranslated): on message handler fires on incoming text message"))
   (deftest "parses socket with absolute ws:// URL"
-    (error "SKIP (untranslated): parses socket with absolute ws:// URL"))
+    (hs-cleanup!)
+    (host-set! (host-global "window") "__hs_ws_created" (list))
+    (eval-hs "socket MySocket ws://localhost:1234/ws end")
+    (let ((sock (host-get (host-global "__hs_ws_created") 0)))
+      (assert= (host-get sock "url") "ws://localhost:1234/ws")))
   (deftest "rpc proxy blacklists then/catch/length/toJSON"
     (error "SKIP (untranslated): rpc proxy blacklists then/catch/length/toJSON"))
   (deftest "rpc proxy default timeout rejects the promise"

tests/hs-run-filtered.js

@@ -534,7 +534,10 @@ globalThis.getSelection=()=>({toString:()=>(globalThis.__test_selection||'')});
 // HsWebSocket — cluster-36 WebSocket mock. Records every constructed socket
 // in globalThis.__hs_ws_created so tests can assert on URLs and sent frames.
 // Tests may override globalThis.WebSocket before activating hyperscript.
-globalThis.__hs_ws_created = [];
+// __hs_ws_created is a plain object with numeric keys (NOT a JS array).
+// JS arrays are auto-converted to SX lists by host-global; plain objects stay foreign.
+// host-get foreign 0  →  foreign[0]  →  mock sock  ✓
+globalThis.__hs_ws_created = {_len: 0};
 globalThis.WebSocket = function HsWebSocket(url) {
   const sock = {
     url,
@@ -546,7 +549,11 @@ globalThis.WebSocket = function HsWebSocket(url) {
     removeEventListener(t, h) { const a = sock._listeners[t]; if (a) { const i = a.indexOf(h); if (i >= 0) a.splice(i, 1); } },
     close() { (sock._listeners['close'] || []).forEach(h => { try { h({}); } catch(_) {} }); }
   };
-  globalThis.__hs_ws_created.push(sock);
+  // If the test reset __hs_ws_created to a SX list (via host-set! ... (list)), reinitialise.
+  if (typeof globalThis.__hs_ws_created?._len !== 'number') globalThis.__hs_ws_created = {_len: 0};
+  const idx = globalThis.__hs_ws_created._len;
+  globalThis.__hs_ws_created[idx] = sock;
+  globalThis.__hs_ws_created._len++;
   return sock;
 };
 // _hs_make_rpc_proxy — cluster-36 RPC proxy factory. Called by the runtime
@@ -746,7 +753,8 @@ for(let i=startTest;i<Math.min(endTest,testCount);i++){
   try{
     // Use SX-level guard to catch errors, avoiding __sxR side-channel issues
     // Returns a dict with :ok and :error keys
-    K.eval(`(define _test-result (_run-test-thunk (get (nth _test-registry ${i}) "thunk")))`);
+    const _dbgR=K.eval(`(define _test-result (_run-test-thunk (get (nth _test-registry ${i}) "thunk")))`);
+    if(suite==='hs-upstream-socket'&&i<=1292)process.stderr.write(`[D] i=${i} r=${JSON.stringify(_dbgR)?.slice(0,100)}\n`);
     const isOk=K.eval('(get _test-result "ok")');
     if(isOk===true){ok=true;}
     else{

tests/playwright/generate-sx-tests.py

@@ -1894,6 +1894,40 @@ def generate_eval_only_test(test, idx):
             f'    (assert (nil? (eval-hs "cookies.foo"))))'
         )
 
+    # Special case: cluster-36 socket URL tests. These check URL normalisation
+    # by running the socket feature with a mock WebSocket and asserting the
+    # URL passed to the constructor.
+    if test['name'] in (
+        'converts relative URL to ws:// on http pages',
+        'converts relative URL to wss:// on https pages',
+        'parses socket with absolute ws:// URL',
+    ):
+        https_mode = 'wss' in test['name']
+        if test['name'] == 'parses socket with absolute ws:// URL':
+            hs_src = 'socket MySocket ws://localhost:1234/ws end'
+            expected_url = 'ws://localhost:1234/ws'
+            proto_setup = ''
+            proto_restore = ''
+        else:
+            hs_src = 'socket RelSocket /my-ws end'
+            expected_url = 'wss://localhost/my-ws' if https_mode else 'ws://localhost/my-ws'
+            if https_mode:
+                proto_setup = '    (host-set! (host-global "location") "protocol" "https:")\n'
+                proto_restore = '    (host-set! (host-global "location") "protocol" "http:")\n'
+            else:
+                proto_setup = ''
+                proto_restore = ''
+        return (
+            f'  (deftest "{safe_name}"\n'
+            f'    (hs-cleanup!)\n'
+            f'    (host-set! (host-global "window") "__hs_ws_created" (list))\n'
+            + proto_setup +
+            f'    (eval-hs "{hs_src}")\n'
+            + proto_restore +
+            f'    (let ((sock (host-get (host-global "__hs_ws_created") 0)))\n'
+            f'      (assert= (host-get sock "url") "{expected_url}")))' 
+        )
+
     # Special case: cluster-29 init events. The two tractable tests both attach
     # listeners to a wa container, set its innerHTML to a hyperscript fragment,
     # then call `_hyperscript.processNode(wa)`. Hand-roll deftests using