Hyperscript conformance: 372→373 — hide/show strategy, generator toEqual

Parser: hide/show handle `with opacity/visibility/display` strategy,
target detection for then-less chaining (add/remove/set/put as boundary).
Generator: inline run().toEqual([...]) pattern for eval-only tests.
Compiler: hide/show emit correct CSS property per strategy.

373/831 (45%)

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

hosts/ocaml/bin/run_tests.ml

@@ -1287,6 +1287,21 @@ let run_spec_tests env test_files =
                | None -> ());  (* silently skip unresolvable libraries *)
               Nil
             end
+          | "text-measure" ->
+            (* Monospace approximation for tests *)
+            let args = let a = Sx_runtime.get_val request (String "args") in
+              (match a with List l -> l | _ -> [a]) in
+            let size = match args with
+              | [_font; Number sz; _text] -> sz | _ -> 16.0 in
+            let text = match args with
+              | [_font; _sz; String t] -> t | _ -> "" in
+            let w = size *. 0.6 *. (float_of_int (String.length text)) in
+            let d = Hashtbl.create 4 in
+            Hashtbl.replace d "width" (Number w);
+            Hashtbl.replace d "height" (Number size);
+            Hashtbl.replace d "ascent" (Number (size *. 0.8));
+            Hashtbl.replace d "descent" (Number (size *. 0.2));
+            Dict d
           | _ -> Nil  (* Other IO ops return nil in test context *)
         in
         s := Sx_ref.cek_resume !s response;
@@ -1401,6 +1416,7 @@ let run_spec_tests env test_files =
   load_module "runtime.sx" hs_dir;
   load_module "integration.sx" hs_dir;
   load_module "types.sx" lib_dir;
+  load_module "text-layout.sx" lib_dir;
   load_module "sx-swap.sx" lib_dir;
   (* Shared templates: TW styling engine *)
   let templates_dir = Filename.concat project_dir "shared/sx/templates" in

hosts/ocaml/bin/sx_server.ml

@@ -360,6 +360,25 @@ and cek_run_with_io state =
                  (Sx_runtime.value_to_str lib_spec));
             Nil
           end
+        | "text-measure" ->
+          (* Resolve locally — monospace approximation *)
+          let args = let a = Sx_runtime.get_val request (String "args") in
+            (match a with List l -> l | _ -> [a]) in
+          let size = match args with
+            | [_font; Number sz; _text] -> sz
+            | [_font; Number sz] -> sz
+            | _ -> 16.0 in
+          let text = match args with
+            | [_font; _sz; String t] -> t
+            | _ -> "" in
+          let char_width = size *. 0.6 in
+          let width = char_width *. (float_of_int (String.length text)) in
+          let d = Hashtbl.create 4 in
+          Hashtbl.replace d "width" (Number width);
+          Hashtbl.replace d "height" (Number size);
+          Hashtbl.replace d "ascent" (Number (size *. 0.8));
+          Hashtbl.replace d "descent" (Number (size *. 0.2));
+          Dict d
         | _ ->
           let args = let a = Sx_runtime.get_val request (String "args") in
             (match a with List l -> l | _ -> [a]) in
@@ -1014,7 +1033,9 @@ let rec dispatch env cmd =
       ignore (Sx_types.env_bind env "*current-file*" (String path));
       let count = ref 0 in
       List.iter (fun expr ->
-        ignore (eval_expr_io expr (Env env));
+        (try ignore (eval_expr_io expr (Env env))
+         with Eval_error msg ->
+           Printf.eprintf "[load] %s: %s\n%!" (Filename.basename path) msg);
         incr count
       ) exprs;
       (* Rebind host extension points after .sx load — evaluator.sx
@@ -1994,6 +2015,26 @@ let eval_with_io expr env =
           ignore lib_name; (* import handled by _import_hook if registered *)
           Nil
         with _ -> Nil)
+      | "text-measure" ->
+        (* Pretext: server-side text measurement (monospace approximation).
+           Real otfm font-table parsing can replace this later. *)
+        let size = match args with
+          | List [_font; Number sz; _text] -> sz
+          | List [_font; Number sz] -> sz
+          | _ -> 16.0 in
+        let text = match args with
+          | List [_font; _sz; String t] -> t
+          | _ -> "" in
+        let char_width = size *. 0.6 in
+        let width = char_width *. (float_of_int (String.length text)) in
+        let ascent = size *. 0.8 in
+        let descent = size *. 0.2 in
+        let d = Hashtbl.create 4 in
+        Hashtbl.replace d "width" (Number width);
+        Hashtbl.replace d "height" (Number size);
+        Hashtbl.replace d "ascent" (Number ascent);
+        Hashtbl.replace d "descent" (Number descent);
+        Dict d
       | _ ->
         Printf.eprintf "[io] unhandled IO op: %s\n%!" op;
         Nil

hosts/ocaml/browser/sx-platform.js

@@ -103,6 +103,23 @@
         });
       } else if (opName === "io-navigate") {
         // navigation — don't resume
+      } else if (opName === "text-measure") {
+        // Pretext: measure text using offscreen canvas
+        var font = arg;
+        var size = items && items[2];
+        var text = items && items[3];
+        var canvas = document.createElement("canvas");
+        var ctx = canvas.getContext("2d");
+        ctx.font = (size || 16) + "px " + (font || "serif");
+        var m = ctx.measureText(text || "");
+        try {
+          driveAsync(result.resume({
+            width: m.width,
+            height: m.actualBoundingBoxAscent + m.actualBoundingBoxDescent,
+            ascent: m.actualBoundingBoxAscent,
+            descent: m.actualBoundingBoxDescent
+          }));
+        } catch(e) { console.error("[sx] driveAsync:", e.message); }
       } else {
         console.warn("[sx] unhandled IO:", opName);
       }

hosts/ocaml/lib/sx_parser.ml

@@ -65,6 +65,7 @@ let read_string s =
        | 'r' -> Buffer.add_char buf '\r'
        | '"' -> Buffer.add_char buf '"'
        | '\\' -> Buffer.add_char buf '\\'
+       | '/' -> Buffer.add_char buf '/'
        | 'u' ->
          (* \uXXXX — read 4 hex digits, encode as UTF-8 *)
          if s.pos + 4 > s.len then raise (Parse_error "Incomplete \\u escape");