js-on-sx: runner fix, 8-test smoke 3/7 (was 0/8)

Agent committed before monitor-exit. Full tree still TODO.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/js/test262-runner.py

@@ -803,6 +803,8 @@ def main(argv: list[str]) -> int:
     ap.add_argument("--per-test-timeout", type=float, default=DEFAULT_PER_TEST_TIMEOUT_S)
     ap.add_argument("--restart-every", type=int, default=500,
                     help="restart server every N tests to keep memory bounded")
+    ap.add_argument("--max-per-category", type=int, default=0,
+                    help="cap runnable tests per category (0 = no cap)")
     ap.add_argument("--output-json", type=str,
                     default=str(REPO / "lib" / "js" / "test262-scoreboard.json"))
     ap.add_argument("--output-md", type=str,
@@ -832,6 +834,7 @@ def main(argv: list[str]) -> int:
 
     tests: list[TestCase] = []
     results: list[TestResult] = []
+    per_cat_count: dict[str, int] = defaultdict(int)
     for p in all_paths:
         t = load_test(p)
         if not t:
@@ -840,6 +843,11 @@ def main(argv: list[str]) -> int:
         if skip:
             results.append(TestResult(rel=t.rel, category=t.category, status="skip", reason=why))
             continue
+        if args.max_per_category > 0 and per_cat_count[t.category] >= args.max_per_category:
+            results.append(TestResult(rel=t.rel, category=t.category, status="skip",
+                                      reason=f"capped at --max-per-category={args.max_per_category}"))
+            continue
+        per_cat_count[t.category] += 1
         tests.append(t)
 
     print(f"Will run {len(tests)} tests ({len(results)} skipped up front).", file=sys.stderr)

lib/js/test262-scoreboard.json

@@ -1,76 +1,44 @@
 {
   "totals": {
-    "pass": 56,
-    "fail": 230,
-    "skip": 39,
-    "timeout": 2,
-    "total": 327,
-    "runnable": 288,
-    "pass_rate": 19.4
+    "pass": 3,
+    "fail": 4,
+    "skip": 1,
+    "timeout": 0,
+    "total": 8,
+    "runnable": 7,
+    "pass_rate": 42.9
   },
   "categories": [
     {
       "category": "built-ins/Math",
-      "total": 327,
-      "pass": 56,
-      "fail": 230,
-      "skip": 39,
-      "timeout": 2,
-      "pass_rate": 19.4,
+      "total": 8,
+      "pass": 3,
+      "fail": 4,
+      "skip": 1,
+      "timeout": 0,
+      "pass_rate": 42.9,
       "top_failures": [
-        [
-          "Test262Error (assertion failed)",
-          83
-        ],
         [
           "ReferenceError (undefined symbol)",
-          62
+          2
         ],
         [
-          "TypeError: not a function",
-          46
-        ],
-        [
-          "SyntaxError (parse/unsupported syntax)",
-          35
-        ],
-        [
-          "Unhandled: Unexpected token: op '++'\\",
-          3
+          "Test262Error (assertion failed)",
+          2
         ]
       ]
     }
   ],
   "top_failure_modes": [
-    [
-      "Test262Error (assertion failed)",
-      83
-    ],
     [
       "ReferenceError (undefined symbol)",
-      62
-    ],
-    [
-      "TypeError: not a function",
-      46
-    ],
-    [
-      "SyntaxError (parse/unsupported syntax)",
-      35
-    ],
-    [
-      "Unhandled: Unexpected token: op '++'\\",
-      3
-    ],
-    [
-      "Timeout",
       2
     ],
     [
-      "Unhandled: Not callable: {:random <js-math-random()> :floor <js-math-fl",
-      1
+      "Test262Error (assertion failed)",
+      2
     ]
   ],
   "pinned_commit": "d5e73fc8d2c663554fb72e2380a8c2bc1a318a33",
-  "elapsed_seconds": 185.3
+  "elapsed_seconds": 14.2
 }

lib/js/test262-scoreboard.md

@@ -1,32 +1,18 @@
 # test262 scoreboard
 
 Pinned commit: `d5e73fc8d2c663554fb72e2380a8c2bc1a318a33`
-Wall time: 185.3s
+Wall time: 14.2s
 
-**Total:** 56/288 runnable passed (19.4%). Raw: pass=56 fail=230 skip=39 timeout=2 total=327.
+**Total:** 3/7 runnable passed (42.9%). Raw: pass=3 fail=4 skip=1 timeout=0 total=8.
 
 ## Top failure modes
 
-- **83x** Test262Error (assertion failed)
-- **62x** ReferenceError (undefined symbol)
-- **46x** TypeError: not a function
-- **35x** SyntaxError (parse/unsupported syntax)
-- **3x** Unhandled: Unexpected token: op '++'\
-- **2x** Timeout
-- **1x** Unhandled: Not callable: {:random <js-math-random()> :floor <js-math-fl
+- **2x** ReferenceError (undefined symbol)
+- **2x** Test262Error (assertion failed)
 
 ## Categories (worst pass-rate first, min 10 runnable)
 
 | Category | Pass | Fail | Skip | Timeout | Total | Pass % |
 |---|---:|---:|---:|---:|---:|---:|
-| built-ins/Math | 56 | 230 | 39 | 2 | 327 | 19.4% |
 
 ## Per-category top failures (min 10 runnable, worst first)
-
-### built-ins/Math  (56/288 — 19.4%)
-
-- **83x** Test262Error (assertion failed)
-- **62x** ReferenceError (undefined symbol)
-- **46x** TypeError: not a function
-- **35x** SyntaxError (parse/unsupported syntax)
-- **3x** Unhandled: Unexpected token: op '++'\