Fix 30 test failures: OCaml renderer primitives + condition signal rename

OCaml HTML renderer (sx_render.ml) silently returned "" when env_get
failed for primitive function calls (str, +, len, etc.) inside HTML
elements. The Eval_error catch now falls through to eval_expr which
resolves primitives correctly. Fixes 21 rendering tests.

Rename condition system special form from "signal" to "signal-condition"
in evaluator.sx, matching the OCaml bootstrapped evaluator (sx_ref.ml).
This avoids clashing with the reactive signal function. Fixes 9
condition system tests.

1166 passed, 0 failed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/ocaml/lib/sx_render.ml

@@ -280,7 +280,10 @@ and render_list_to_html head args env =
        | _ ->
          let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
          do_render_to_html result env)
-    with Eval_error _ -> "")
+    with Eval_error _ ->
+      (* Symbol not in env — might be a primitive; eval the full expression *)
+      let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
+      do_render_to_html result env)
   | _ ->
     let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
     do_render_to_html result env
@@ -530,10 +533,13 @@ and render_list_buf buf head args env =
        | _ ->
          let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
          render_to_buf buf result env)
-    with Eval_error msg ->
-      (* Unknown symbol/component — skip silently during SSR.
-         The client will render from page-sx. *)
-      Printf.eprintf "[ssr-skip] %s\n%!" msg)
+    with Eval_error _ ->
+      (* Symbol not in env — might be a primitive; eval the full expression *)
+      (try
+        let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
+        render_to_buf buf result env
+      with Eval_error msg ->
+        Printf.eprintf "[ssr-skip] %s\n%!" msg))
   | _ ->
     (try
       let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in

spec/evaluator.sx

@@ -1050,7 +1050,7 @@
               ("emitted" (step-sf-emitted args env kont))
               ("handler-bind" (step-sf-handler-bind args env kont))
               ("restart-case" (step-sf-restart-case args env kont))
-              ("signal" (step-sf-signal args env kont))
+              ("signal-condition" (step-sf-signal args env kont))
               ("invoke-restart" (step-sf-invoke-restart args env kont))
               ("match" (step-sf-match args env kont))
               ("dynamic-wind"

spec/tests/test-conditions.sx

@@ -0,0 +1,109 @@
+(defsuite
+  "handler-bind-basic"
+  (deftest
+    "handler-bind returns body value when no signal"
+    (assert-equal
+      42
+      (handler-bind (((fn (c) true) (fn (c) "handled"))) 42)))
+  (deftest
+    "signal with matching handler returns handler value"
+    (assert-equal
+      "handled: boom"
+      (handler-bind
+        (((fn (c) true) (fn (c) (str "handled: " c))))
+        (signal-condition "boom"))))
+  (deftest
+    "signal without handler errors"
+    (assert-throws (fn () (signal-condition "unhandled"))))
+  (deftest
+    "signal returns handler value to call site"
+    (assert-equal
+      51
+      (handler-bind
+        (((fn (c) true) (fn (c) (* c 10))))
+        (+ 1 (signal-condition 5)))))
+  (deftest
+    "handler-bind multiple handlers picks first match"
+    (assert-equal
+      "got-b"
+      (handler-bind
+        (((fn (c) (= c "type-a")) (fn (c) "got-a"))
+          ((fn (c) (= c "type-b")) (fn (c) "got-b")))
+        (signal-condition "type-b"))))
+  (deftest
+    "nested handler-bind inner takes precedence"
+    (assert-equal
+      "inner-handler"
+      (handler-bind
+        (((fn (c) true) (fn (c) "outer")))
+        (handler-bind
+          (((fn (c) (= c "inner")) (fn (c) "inner-handler")))
+          (signal-condition "inner")))))
+  (deftest
+    "handler-bind with multi-expression body"
+    (assert-equal
+      10
+      (handler-bind (((fn (c) true) (fn (c) c))) (+ 1 2) (* 2 5)))))
+
+(defsuite
+  "restart-case-basic"
+  (deftest
+    "restart-case returns body value when no signal"
+    (assert-equal 3 (restart-case (+ 1 2) (use-default () 0))))
+  (deftest
+    "invoke-restart finds and runs restart"
+    (assert-equal
+      42
+      (handler-bind
+        (((fn (c) true) (fn (c) (invoke-restart (quote use-default)))))
+        (restart-case
+          (do (signal-condition "bad") "unreachable")
+          (use-default () 42)))))
+  (deftest
+    "invoke-restart with argument"
+    (assert-equal
+      99
+      (handler-bind
+        (((fn (c) true) (fn (c) (invoke-restart (quote use-value) 99))))
+        (restart-case
+          (do (signal-condition "bad") "unreachable")
+          (use-value (v) v)))))
+  (deftest
+    "invoke-restart unknown name errors"
+    (assert-throws (fn () (invoke-restart (quote nonexistent)))))
+  (deftest
+    "nested restart-case uses inner restart"
+    (assert-equal
+      "inner-fallback"
+      (handler-bind
+        (((fn (c) true) (fn (c) (invoke-restart (quote fallback)))))
+        (restart-case
+          (restart-case
+            (do (signal-condition "err") "unreachable")
+            (fallback () "inner-fallback"))
+          (fallback () "outer-fallback")))))
+  (deftest
+    "signal + restart computes replacement value"
+    (assert-equal
+      25
+      (handler-bind
+        (((fn (c) true) (fn (c) (invoke-restart (quote use-value) (* c 3)))))
+        (+ 10 (restart-case (signal-condition 5) (use-value (v) v)))))))
+
+(defsuite
+  "comp-trace"
+  (deftest
+    "component call creates trace frame"
+    (defcomp ~trace-inner () "inner")
+    (assert-equal "inner" (~trace-inner)))
+  (deftest
+    "nested component calls work"
+    (defcomp ~trace-child () "child")
+    (defcomp ~trace-parent () (~trace-child))
+    (assert-equal "child" (~trace-parent)))
+  (deftest
+    "component error via cek-try"
+    (defcomp ~broken-comp () (error "deliberate"))
+    (let
+      ((result (cek-try (fn () (~broken-comp)))))
+      (assert-true (= (type-of result) "list")))))