HS tests: sync textContent when innerHTML is set

When innerHTML is set on a mock element, textContent now updates to
match (with HTML tags stripped). Many HS tests do `put "foo" into me`
(which sets innerHTML) then check textContent. Previously textContent
stayed empty because only innerHTML was updated.

Also fixes innerHTML="" to fully detach children from parent.

393 → 408/831 HS tests (+15).

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

hosts/ocaml/bin/run_tests.ml

@@ -1669,18 +1669,25 @@ let run_spec_tests env test_files =
           | Some (Dict _cl) -> () (* classes live in className *)
           | _ -> ())
        | "innerHTML" ->
-         (* Setting innerHTML clears children (like a real browser) *)
+         (* Setting innerHTML clears children and syncs textContent (like a browser) *)
+         let kids = match Hashtbl.find_opt d "children" with Some (List l) -> l | _ -> [] in
+         List.iter (fun c -> match c with Dict cd ->
+           Hashtbl.replace cd "parentElement" Nil;
+           Hashtbl.replace cd "parentNode" Nil | _ -> ()) kids;
+         Hashtbl.replace d "children" (List []);
+         Hashtbl.replace d "childNodes" (List []);
+         (* Approximate textContent: strip HTML tags from innerHTML *)
          (match stored with
-          | String "" ->
+          | String s ->
-            (* Detach children *)
+            let buf = Buffer.create (String.length s) in
-            let kids = match Hashtbl.find_opt d "children" with Some (List l) -> l | _ -> [] in
+            let in_tag = ref false in
-            List.iter (fun c -> match c with Dict cd ->
+            String.iter (fun c ->
-              Hashtbl.replace cd "parentElement" Nil;
+              if c = '<' then in_tag := true
-              Hashtbl.replace cd "parentNode" Nil | _ -> ()) kids;
+              else if c = '>' then in_tag := false
-            Hashtbl.replace d "children" (List []);
+              else if not !in_tag then Buffer.add_char buf c
-            Hashtbl.replace d "childNodes" (List []);
+            ) s;
-            Hashtbl.replace d "textContent" (String "")
+            Hashtbl.replace d "textContent" (String (Buffer.contents buf))
-          | _ -> ())
+          | _ -> Hashtbl.replace d "textContent" (String ""))
        | "textContent" ->
          (* Setting textContent clears children *)
          Hashtbl.replace d "children" (List []);