From 2d475f95d1195e885c3dd7fb8a7435dafe1f34df Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Thu, 7 May 2026 20:14:15 +0000
Subject: [PATCH] js-on-sx: constructors carry __proto__ = Function.prototype
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Object/Array/Number/String/Boolean had no __proto__, so
Function.prototype mutations were invisible to them. Added a
post-init (begin (dict-set! ...)) at the end of runtime.sx
that wires each constructor to js-function-global.prototype.
Combined with the recent Object.prototype fallback, the chain
now terminates correctly: ctor → Function.prototype → Object.prototype.
built-ins/Number: 41/50 → 42/50, built-ins/String: 75/99 → 78/99,
built-ins/Array: 12/45 → 13/45. conformance.sh: 148/148.
---
 lib/js/runtime.sx              | 361 +++++++++++++++++++++++++--------
 lib/js/test262-scoreboard.json |  18 +-
 lib/js/test262-scoreboard.md   |  12 +-
 plans/js-on-sx.md              |   2 +
 4 files changed, 291 insertions(+), 102 deletions(-)

diff --git a/lib/js/runtime.sx b/lib/js/runtime.sx
index 0fff6486..42f9f843 100644
--- a/lib/js/runtime.sx
+++ b/lib/js/runtime.sx
@@ -122,7 +122,9 @@
 
 (define
   js-extract-fn-name
-  (fn (f) (let ((raw (inspect f))) (js-strip-fn-name raw 0 (len raw)))))
+  (fn
+    (f)
+    (let ((raw (inspect f))) (js-strip-fn-name raw 0 (len raw)))))
 
 (define
   js-strip-fn-name
@@ -240,7 +242,8 @@
       ((= key "apply")
         (let
           ((this-arg (if (< (len args) 1) :js-undefined (nth args 0)))
-            (arr (if (< (len args) 2) (list) (nth args 1))))
+            (arr
+              (if (< (len args) 2) (list) (nth args 1))))
           (let
             ((rest (cond ((= arr nil) (list)) ((js-undefined? arr) (list)) ((list? arr) arr) (else (js-iterable-to-list arr)))))
             (js-call-with-this this-arg recv rest))))
@@ -368,7 +371,10 @@
     (d)
     (cond
       ((< d 10) (js-to-string d))
-      (else (let ((offset (+ 97 (- d 10)))) (js-code-to-char offset))))))
+      (else
+        (let
+          ((offset (+ 97 (- d 10))))
+          (js-code-to-char offset))))))
 
 ;; ── Equality ──────────────────────────────────────────────────────
 
@@ -410,7 +416,9 @@
 
 (define
   js-pow-int
-  (fn (b e) (if (<= e 0) 1 (* b (js-pow-int b (- e 1))))))
+  (fn
+    (b e)
+    (if (<= e 0) 1 (* b (js-pow-int b (- e 1))))))
 
 ;; Abstract equality (==): type coercion rules.
 ;; Simplified: number↔string coerce both to number; null == undefined;
@@ -711,7 +719,10 @@
             (dict-set!
               this
               "message"
-              (if (= (len args) 0) "" (js-to-string (nth args 0))))
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0))))
             (dict-set! this "name" "Error"))
           nil)
         this))))
@@ -731,7 +742,10 @@
             (dict-set!
               this
               "message"
-              (if (= (len args) 0) "" (js-to-string (nth args 0))))
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0))))
             (dict-set! this "name" "TypeError"))
           nil)
         this))))
@@ -748,7 +762,10 @@
             (dict-set!
               this
               "message"
-              (if (= (len args) 0) "" (js-to-string (nth args 0))))
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0))))
             (dict-set! this "name" "RangeError"))
           nil)
         this))))
@@ -765,7 +782,10 @@
             (dict-set!
               this
               "message"
-              (if (= (len args) 0) "" (js-to-string (nth args 0))))
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0))))
             (dict-set! this "name" "SyntaxError"))
           nil)
         this))))
@@ -782,7 +802,10 @@
             (dict-set!
               this
               "message"
-              (if (= (len args) 0) "" (js-to-string (nth args 0))))
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0))))
             (dict-set! this "name" "ReferenceError"))
           nil)
         this))))
@@ -1016,7 +1039,9 @@
 
 (define js-parse-num-safe (fn (s) (cond (else (js-num-from-string s)))))
 
-(define js-find-exp-char (fn (s) (js-find-exp-char-loop s 0 (len s))))
+(define
+  js-find-exp-char
+  (fn (s) (js-find-exp-char-loop s 0 (len s))))
 
 (define
   js-find-exp-char-loop
@@ -1056,7 +1081,8 @@
           ((c (char-at s i)) (d (js-hex-digit-value (char-at s i))))
           (cond
             ((< d 0) (js-nan-value))
-            (else (js-parse-hex s (+ i 1) (+ (* acc 16) d)))))))))
+            (else
+              (js-parse-hex s (+ i 1) (+ (* acc 16) d)))))))))
 
 (define
   js-hex-digit-value
@@ -1147,7 +1173,8 @@
     (s n)
     (cond
       ((<= n 0) "")
-      ((js-is-space? (char-at s (- n 1))) (js-trim-right-at s (- n 1)))
+      ((js-is-space? (char-at s (- n 1)))
+        (js-trim-right-at s (- n 1)))
       (else (substr s 0 n)))))
 
 (define
@@ -1163,9 +1190,21 @@
       (cond
         ((>= i n) (* sign (if frac? (/ acc fdiv) acc)))
         ((and (= i 0) (= (char-at s 0) "-"))
-          (js-parse-decimal s 1 0 -1 false 0))
+          (js-parse-decimal
+            s
+            1
+            0
+            -1
+            false
+            0))
         ((and (= i 0) (= (char-at s 0) "+"))
-          (js-parse-decimal s 1 0 1 false 0))
+          (js-parse-decimal
+            s
+            1
+            0
+            1
+            false
+            0))
         ((= (char-at s i) ".")
           (js-parse-decimal s (+ i 1) acc sign true 1))
         ((js-is-digit? (char-at s i))
@@ -1342,10 +1381,17 @@
       (let
         ((int-part (if (< di 0) mant (js-string-slice mant 0 di)))
           (frac-part
-            (if (< di 0) "" (js-string-slice mant (+ di 1) (len mant)))))
+            (if
+              (< di 0)
+              ""
+              (js-string-slice mant (+ di 1) (len mant)))))
         (let
           ((all-digits (str int-part frac-part))
-            (frac-len (if (< di 0) 0 (- (- (len mant) di) 1))))
+            (frac-len
+              (if
+                (< di 0)
+                0
+                (- (- (len mant) di) 1))))
           (if
             (>= exp-n 0)
             (if
@@ -1357,7 +1403,10 @@
                   (js-string-slice all-digits 0 dot-pos)
                   "."
                   (js-string-slice all-digits dot-pos (len all-digits)))))
-            (str "0." (js-string-repeat "0" (- (- 0 exp-n) 1)) all-digits)))))))
+            (str
+              "0."
+              (js-string-repeat "0" (- (- 0 exp-n) 1))
+              all-digits)))))))
 
 (define
   js-number-to-string
@@ -1399,7 +1448,8 @@
     (let
       ((sign-and-body (js-split-sign s)))
       (let
-        ((sign (nth sign-and-body 0)) (body (nth sign-and-body 1)))
+        ((sign (nth sign-and-body 0))
+          (body (nth sign-and-body 1)))
         (let
           ((stripped (js-strip-zeros-loop body 0 (len body))))
           (if (= stripped "") (str sign "0") (str sign stripped)))))))
@@ -1410,8 +1460,10 @@
     (s)
     (cond
       ((= s "") (list "" ""))
-      ((= (char-at s 0) "-") (list "-" (js-string-slice s 1 (len s))))
-      ((= (char-at s 0) "+") (list "" (js-string-slice s 1 (len s))))
+      ((= (char-at s 0) "-")
+        (list "-" (js-string-slice s 1 (len s))))
+      ((= (char-at s 0) "+")
+        (list "" (js-string-slice s 1 (len s))))
       (else (list "" s)))))
 
 (define
@@ -1459,7 +1511,9 @@
 
 (define js-not (fn (a) (not (js-to-boolean a))))
 
-(define js-bitnot (fn (a) (- 0 (+ (js-num-to-int (js-to-number a)) 1))))
+(define
+  js-bitnot
+  (fn (a) (- 0 (+ (js-num-to-int (js-to-number a)) 1))))
 
 (define
   js-strict-eq
@@ -1511,7 +1565,9 @@
 
 (define js-ge (fn (a b) (not (js-lt a b))))
 
-(define js-str-lt (fn (a b) (js-str-lt-at a b 0 (len a) (len b))))
+(define
+  js-str-lt
+  (fn (a b) (js-str-lt-at a b 0 (len a) (len b))))
 
 (define
   js-str-lt-at
@@ -1572,7 +1628,10 @@
             (js-list-index-of
               arr
               (nth args 0)
-              (if (< (len args) 2) 0 (js-num-to-int (nth args 1)))))))
+              (if
+                (< (len args) 2)
+                0
+                (js-num-to-int (nth args 1)))))))
       ((= name "join")
         (fn
           (&rest args)
@@ -1581,9 +1640,12 @@
             (js-list-join arr sep))))
       ((= name "concat") (fn (&rest args) (js-list-concat arr args)))
       ((= name "map") (fn (f) (js-list-map-loop f arr 0 (list))))
-      ((= name "filter") (fn (f) (js-list-filter-loop f arr 0 (list))))
+      ((= name "filter")
+        (fn (f) (js-list-filter-loop f arr 0 (list))))
       ((= name "forEach")
-        (fn (f) (begin (js-list-foreach-loop f arr 0) js-undefined)))
+        (fn
+          (f)
+          (begin (js-list-foreach-loop f arr 0) js-undefined)))
       ((= name "reduce")
         (fn
           (&rest args)
@@ -1592,17 +1654,29 @@
               (if
                 (= (len arr) 0)
                 (error "Reduce of empty array with no initial value")
-                (js-list-reduce-loop (nth args 0) (nth arr 0) arr 1)))
-            (else (js-list-reduce-loop (nth args 0) (nth args 1) arr 0)))))
+                (js-list-reduce-loop
+                  (nth args 0)
+                  (nth arr 0)
+                  arr
+                  1)))
+            (else
+              (js-list-reduce-loop
+                (nth args 0)
+                (nth args 1)
+                arr
+                0)))))
       ((= name "includes")
         (fn
           (&rest args)
           (if
             (= (len args) 0)
             false
-            (>= (js-list-index-of arr (nth args 0) 0) 0))))
+            (>=
+              (js-list-index-of arr (nth args 0) 0)
+              0))))
       ((= name "find") (fn (f) (js-list-find-loop f arr 0)))
-      ((= name "findIndex") (fn (f) (js-list-find-index-loop f arr 0)))
+      ((= name "findIndex")
+        (fn (f) (js-list-find-index-loop f arr 0)))
       ((= name "some") (fn (f) (js-list-some-loop f arr 0)))
       ((= name "every") (fn (f) (js-list-every-loop f arr 0)))
       ((= name "reverse")
@@ -1618,7 +1692,11 @@
           (&rest args)
           (let
             ((v (if (= (len args) 0) js-undefined (nth args 0)))
-              (s (if (< (len args) 2) 0 (js-num-to-int (nth args 1))))
+              (s
+                (if
+                  (< (len args) 2)
+                  0
+                  (js-num-to-int (nth args 1))))
               (e
                 (if
                   (< (len args) 3)
@@ -1662,7 +1740,11 @@
           (&rest args)
           (let
             ((n (len arr))
-              (start-raw (if (empty? args) 0 (js-num-to-int (nth args 0)))))
+              (start-raw
+                (if
+                  (empty? args)
+                  0
+                  (js-num-to-int (nth args 0)))))
             (let
               ((start (cond ((< start-raw 0) (max 0 (+ n start-raw))) ((> start-raw n) n) (else start-raw))))
               (let
@@ -1677,7 +1759,9 @@
       ((= name "findLast")
         (fn (f) (js-list-find-last-loop f arr (- (len arr) 1))))
       ((= name "findLastIndex")
-        (fn (f) (js-list-find-last-index-loop f arr (- (len arr) 1))))
+        (fn
+          (f)
+          (js-list-find-last-index-loop f arr (- (len arr) 1))))
       ((= name "reduceRight")
         (fn
           (&rest args)
@@ -1718,9 +1802,15 @@
           (let
             ((n (len arr))
               (target-raw
-                (if (empty? args) 0 (js-num-to-int (nth args 0))))
+                (if
+                  (empty? args)
+                  0
+                  (js-num-to-int (nth args 0))))
               (start-raw
-                (if (< (len args) 2) 0 (js-num-to-int (nth args 1))))
+                (if
+                  (< (len args) 2)
+                  0
+                  (js-num-to-int (nth args 1))))
               (end-raw
                 (if
                   (< (len args) 3)
@@ -1730,7 +1820,8 @@
               ((target (cond ((< target-raw 0) (max 0 (+ n target-raw))) (else (min n target-raw))))
                 (start
                   (cond
-                    ((< start-raw 0) (max 0 (+ n start-raw)))
+                    ((< start-raw 0)
+                      (max 0 (+ n start-raw)))
                     (else (min n start-raw))))
                 (end
                   (cond
@@ -1760,7 +1851,11 @@
       ((n (len arr)))
       (let
         ((s (if (< start 0) (max 0 (+ n start)) (min start n)))
-          (e (if (< stop 0) (max 0 (+ n stop)) (min stop n))))
+          (e
+            (if
+              (< stop 0)
+              (max 0 (+ n stop))
+              (min stop n))))
         (js-list-slice-loop arr s e (list))))))
 
 (define
@@ -1790,7 +1885,11 @@
     (cond
       ((= (len arr) 0) "")
       (else
-        (js-list-join-loop arr sep 1 (js-to-string-for-join (nth arr 0)))))))
+        (js-list-join-loop
+          arr
+          sep
+          1
+          (js-to-string-for-join (nth arr 0)))))))
 
 (define
   js-to-string-for-join
@@ -1859,7 +1958,8 @@
     (f arr i)
     (cond
       ((>= i (len arr)) nil)
-      (else (do (f (nth arr i)) (js-list-foreach-loop f arr (+ i 1)))))))
+      (else
+        (do (f (nth arr i)) (js-list-foreach-loop f arr (+ i 1)))))))
 
 (define
   js-list-reduce-loop
@@ -1867,7 +1967,8 @@
     (f acc arr i)
     (cond
       ((>= i (len arr)) acc)
-      (else (js-list-reduce-loop f (f acc (nth arr i)) arr (+ i 1))))))
+      (else
+        (js-list-reduce-loop f (f acc (nth arr i)) arr (+ i 1))))))
 
 (define
   js-list-find-loop
@@ -1918,11 +2019,15 @@
       ((>= s e) nil)
       ((>= s (len arr)) nil)
       (else
-        (begin (js-list-set! arr s v) (js-list-fill-loop arr v (+ s 1) e))))))
+        (begin
+          (js-list-set! arr s v)
+          (js-list-fill-loop arr v (+ s 1) e))))))
 
 (define
   js-list-sort!
-  (fn (arr cmp) (let ((n (len arr))) (js-list-sort-outer! arr cmp 0 n))))
+  (fn
+    (arr cmp)
+    (let ((n (len arr))) (js-list-sort-outer! arr cmp 0 n))))
 
 (define
   js-list-sort-outer!
@@ -1949,7 +2054,9 @@
               ((result (if (= cmp nil) (if (js-str-lt (js-to-string b) (js-to-string a)) 1 -1) (js-to-number (cmp a b)))))
               (when
                 (> result 0)
-                (begin (js-list-set! arr i b) (js-list-set! arr (+ i 1) a)))))
+                (begin
+                  (js-list-set! arr i b)
+                  (js-list-set! arr (+ i 1) a)))))
           (js-list-sort-inner! arr cmp (+ i 1) end))))))
 
 (define
@@ -2015,7 +2122,9 @@
     (if
       (>= i (len arr))
       result
-      (begin (append! result i) (js-list-keys-loop arr (+ i 1) result)))))
+      (begin
+        (append! result i)
+        (js-list-keys-loop arr (+ i 1) result)))))
 
 (define
   js-list-entries-loop
@@ -2052,7 +2161,10 @@
   js-string-repeat
   (fn
     (s n acc)
-    (if (<= n 0) acc (js-string-repeat s (- n 1) (str acc s)))))
+    (if
+      (<= n 0)
+      acc
+      (js-string-repeat s (- n 1) (str acc s)))))
 
 (define
   js-string-pad
@@ -2379,7 +2491,11 @@
       ((n (len s)))
       (let
         ((lo (if (< start 0) (max 0 (+ n start)) (min start n)))
-          (hi (if (< stop 0) (max 0 (+ n stop)) (min stop n))))
+          (hi
+            (if
+              (< stop 0)
+              (max 0 (+ n stop))
+              (min stop n))))
         (if (>= lo hi) "" (js-string-slice-loop s lo hi ""))))))
 
 (define
@@ -2388,7 +2504,8 @@
     (s i e acc)
     (cond
       ((>= i e) acc)
-      (else (js-string-slice-loop s (+ i 1) e (str acc (char-at s i)))))))
+      (else
+        (js-string-slice-loop s (+ i 1) e (str acc (char-at s i)))))))
 
 (define
   js-string-index-of
@@ -2738,7 +2855,9 @@
   js-math-trunc
   (fn
     (x)
-    (let ((n (js-to-number x))) (if (< n 0) (ceil n) (floor n)))))
+    (let
+      ((n (js-to-number x)))
+      (if (< n 0) (ceil n) (floor n)))))
 
 (define
   js-math-sign
@@ -2746,7 +2865,10 @@
     (x)
     (let
       ((n (js-to-number x)))
-      (cond ((> n 0) 1) ((< n 0) -1) (else n)))))
+      (cond
+        ((> n 0) 1)
+        ((< n 0) -1)
+        (else n)))))
 
 (define
   js-math-cbrt
@@ -2754,9 +2876,14 @@
     (x)
     (let
       ((n (js-to-number x)))
-      (if (< n 0) (- 0 (pow (- 0 n) (/ 1 3))) (pow n (/ 1 3))))))
+      (if
+        (< n 0)
+        (- 0 (pow (- 0 n) (/ 1 3)))
+        (pow n (/ 1 3))))))
 
-(define js-math-hypot (fn (&rest args) (sqrt (js-math-hypot-loop args 0))))
+(define
+  js-math-hypot
+  (fn (&rest args) (sqrt (js-math-hypot-loop args 0))))
 
 (define
   js-math-hypot-loop
@@ -2811,7 +2938,7 @@
           ((result (modulo (* a32 b32) 4294967296)))
           (if (>= result 2147483648) (- result 4294967296) result)))))
   (define js-math-fround (fn (x) (js-to-number x)))
-  (define Math {:trunc js-math-trunc :expm1 js-math-expm1 :atan2 js-math-atan2 :PI 3.14159 :asinh js-math-asinh :acosh js-math-acosh :hypot js-math-hypot :LOG2E 1.4427 :atanh js-math-atanh :ceil js-math-ceil :pow js-math-pow :sin js-math-sin :max js-math-max :log2 js-math-log2 :SQRT2 1.41421 :cbrt js-math-cbrt :log1p js-math-log1p :fround js-math-fround :E 2.71828 :sinh js-math-sinh :random js-math-random :LN10 2.30259 :SQRT1_2 0.707107 :asin js-math-asin :clz32 js-math-clz32 :floor js-math-floor :exp js-math-exp :tan js-math-tan :sqrt js-math-sqrt :cosh js-math-cosh :log js-math-log :round js-math-round :abs js-math-abs :LOG10E 0.434294 :tanh js-math-tanh :acos js-math-acos :log10 js-math-log10 :min js-math-min :sign js-math-sign :LN2 0.693147 :cos js-math-cos :imul js-math-imul :atan js-math-atan}))
+  (define Math {:atan js-math-atan :sign js-math-sign :LN2 0.693147 :cos js-math-cos :imul js-math-imul :min js-math-min :acos js-math-acos :log10 js-math-log10 :LOG10E 0.434294 :tanh js-math-tanh :abs js-math-abs :round js-math-round :log js-math-log :sqrt js-math-sqrt :cosh js-math-cosh :tan js-math-tan :floor js-math-floor :exp js-math-exp :asin js-math-asin :clz32 js-math-clz32 :random js-math-random :LN10 2.30259 :SQRT1_2 0.707107 :sinh js-math-sinh :E 2.71828 :fround js-math-fround :cbrt js-math-cbrt :log1p js-math-log1p :SQRT2 1.41421 :max js-math-max :log2 js-math-log2 :ceil js-math-ceil :pow js-math-pow :sin js-math-sin :hypot js-math-hypot :LOG2E 1.4427 :atanh js-math-atanh :asinh js-math-asinh :acosh js-math-acosh :PI 3.14159 :atan2 js-math-atan2 :trunc js-math-trunc :expm1 js-math-expm1}))
 
 (define
   js-number-is-finite
@@ -2837,9 +2964,7 @@
 
 (define
   js-number-is-safe-integer
-  (fn
-    (v)
-    (and (js-number-is-integer v) (<= (js-math-abs v) 9007199254740991))))
+  (fn (v) (and (js-number-is-integer v) (<= (js-math-abs v) 9007199254740991))))
 
 (define
   js-global-is-finite
@@ -2847,7 +2972,7 @@
 
 (define js-global-is-nan (fn (v) (js-number-is-nan (js-to-number v))))
 
-(define Number {:isFinite js-number-is-finite :MAX_SAFE_INTEGER 9007199254740991 :EPSILON 2.22045e-16 :MAX_VALUE (js-max-value-approx) :POSITIVE_INFINITY (js-infinity-value) :__callable__ js-to-number :isInteger js-number-is-integer :prototype {:valueOf (fn () (js-this)) :toPrecision (fn (&rest args) (js-to-string (js-this))) :toString (fn (&rest args) (let ((this-val (js-this)) (radix (if (empty? args) 10 (js-to-number (nth args 0))))) (js-num-to-str-radix this-val (if (or (= radix nil) (js-undefined? radix)) 10 radix)))) :toLocaleString (fn () (js-to-string (js-this))) :toFixed (fn (d) (js-number-to-fixed (js-this) (if (= d nil) 0 (js-to-number d)))) :toExponential (fn (&rest args) (js-to-string (js-this)))} :isNaN js-number-is-nan :isSafeInteger js-number-is-safe-integer :NEGATIVE_INFINITY (- 0 (js-infinity-value)) :NaN (js-nan-value) :MIN_VALUE 4.94066e-324 :MIN_SAFE_INTEGER -9007199254740991})
+(define Number {:MIN_SAFE_INTEGER -9007199254740991 :MIN_VALUE 4.94066e-324 :isNaN js-number-is-nan :isSafeInteger js-number-is-safe-integer :NEGATIVE_INFINITY (- 0 (js-infinity-value)) :NaN (js-nan-value) :prototype {:toFixed (fn (d) (js-number-to-fixed (js-this) (if (= d nil) 0 (js-to-number d)))) :toExponential (fn (&rest args) (js-to-string (js-this))) :toLocaleString (fn () (js-to-string (js-this))) :toString (fn (&rest args) (let ((this-val (js-this)) (radix (if (empty? args) 10 (js-to-number (nth args 0))))) (js-num-to-str-radix this-val (if (or (= radix nil) (js-undefined? radix)) 10 radix)))) :toPrecision (fn (&rest args) (js-to-string (js-this))) :valueOf (fn () (js-this))} :isInteger js-number-is-integer :__callable__ js-to-number :MAX_VALUE (js-max-value-approx) :POSITIVE_INFINITY (js-infinity-value) :isFinite js-number-is-finite :MAX_SAFE_INTEGER 9007199254740991 :EPSILON 2.22045e-16})
 
 (dict-set! Number "length" 1)
 
@@ -3048,7 +3173,9 @@
     (if
       (>= i (len s))
       acc
-      (begin (append! acc (char-at s i)) (js-string-to-list s (+ i 1) acc)))))
+      (begin
+        (append! acc (char-at s i))
+        (js-string-to-list s (+ i 1) acc)))))
 
 (define
   js-object-keys
@@ -3149,7 +3276,10 @@
             (for-each
               (fn
                 (k)
-                (dict-set! obj k (get (get (nth args 1) k) "value")))
+                (dict-set!
+                  obj
+                  k
+                  (get (get (nth args 1) k) "value")))
               (keys (nth args 1))))
           obj)))))
 
@@ -3180,7 +3310,8 @@
   (fn
     (o)
     (cond
-      ((list? o) (let ((r (list))) (begin (js-list-keys-loop o 0 r) r)))
+      ((list? o)
+        (let ((r (list))) (begin (js-list-keys-loop o 0 r) r)))
       ((dict? o) (js-object-keys o))
       (else (list)))))
 
@@ -3190,7 +3321,7 @@
     (o key)
     (if
       (and (dict? o) (contains? (keys o) (js-to-string key)))
-      {:writable true :value (get o (js-to-string key)) :enumerable true :configurable true}
+      {:configurable true :enumerable true :value (get o (js-to-string key)) :writable true}
       :js-undefined)))
 
 (define
@@ -3241,7 +3372,10 @@
             (pair)
             (when
               (and (list? pair) (>= (len pair) 2))
-              (dict-set! out (js-to-string (nth pair 0)) (nth pair 1))))
+              (dict-set!
+                out
+                (js-to-string (nth pair 0))
+                (nth pair 1))))
           lst)
         out))))
 
@@ -3257,7 +3391,7 @@
           (and (>= idx 0) (< idx (len o)) (integer? idx))))
       (else false))))
 
-(define Object {:entries js-object-entries :defineProperties js-object-define-properties :__callable__ (fn (&rest args) (cond ((= (len args) 0) (dict)) (else (nth args 0)))) :preventExtensions js-object-prevent-extensions :prototype {:valueOf (fn () (js-this)) :propertyIsEnumerable (fn (k) (let ((o (js-this))) (js-object-has-own o k))) :isPrototypeOf (fn (o) (let ((this-val (js-this))) (cond ((not (dict? o)) false) (else (let ((proto (if (contains? (keys o) "__proto__") (get o "__proto__") nil))) (cond ((= proto this-val) true) ((= proto nil) false) (else ((get (get Object "prototype") "isPrototypeOf") proto)))))))) :toString (fn () "[object Object]") :hasOwnProperty (fn (k) (let ((o (js-this))) (js-object-has-own o k))) :toLocaleString (fn () "[object Object]")} :values js-object-values :hasOwn js-object-has-own :freeze js-object-freeze :assign js-object-assign :isFrozen js-object-is-frozen :getOwnPropertyDescriptor js-object-get-own-property-descriptor :fromEntries js-object-from-entries :defineProperty js-object-define-property :setPrototypeOf js-object-set-prototype-of :getOwnPropertyNames js-object-get-own-property-names :getOwnPropertyDescriptors js-object-get-own-property-descriptors :create js-object-create :isExtensible js-object-is-extensible :is js-object-is :keys js-object-keys :getPrototypeOf js-object-get-prototype-of :isSealed js-object-is-sealed :seal js-object-seal})
+(define Object {:keys js-object-keys :getPrototypeOf js-object-get-prototype-of :isSealed js-object-is-sealed :seal js-object-seal :create js-object-create :isExtensible js-object-is-extensible :is js-object-is :setPrototypeOf js-object-set-prototype-of :getOwnPropertyNames js-object-get-own-property-names :getOwnPropertyDescriptors js-object-get-own-property-descriptors :defineProperty js-object-define-property :fromEntries js-object-from-entries :getOwnPropertyDescriptor js-object-get-own-property-descriptor :assign js-object-assign :isFrozen js-object-is-frozen :freeze js-object-freeze :values js-object-values :hasOwn js-object-has-own :prototype {:hasOwnProperty (fn (k) (let ((o (js-this))) (js-object-has-own o k))) :toLocaleString (fn () "[object Object]") :isPrototypeOf (fn (o) (let ((this-val (js-this))) (cond ((not (dict? o)) false) (else (let ((proto (if (contains? (keys o) "__proto__") (get o "__proto__") nil))) (cond ((= proto this-val) true) ((= proto nil) false) (else ((get (get Object "prototype") "isPrototypeOf") proto)))))))) :toString (fn () "[object Object]") :propertyIsEnumerable (fn (k) (let ((o (js-this))) (js-object-has-own o k))) :valueOf (fn () (js-this))} :__callable__ (fn (&rest args) (cond ((= (len args) 0) (dict)) (else (nth args 0)))) :preventExtensions js-object-prevent-extensions :entries js-object-entries :defineProperties js-object-define-properties})
 
 (dict-set! Object "length" 1)
 
@@ -3337,7 +3471,8 @@
       (else
         (let
           ((src (js-iterable-to-list (nth args 0)))
-            (map-fn (if (< (len args) 2) nil (nth args 1))))
+            (map-fn
+              (if (< (len args) 2) nil (nth args 1))))
           (if
             (= map-fn nil)
             (let
@@ -3347,11 +3482,14 @@
             (let
               ((result (list)) (i 0))
               (for-each
-                (fn (x) (append! result (map-fn x)) (set! i (+ i 1)))
+                (fn
+                  (x)
+                  (append! result (map-fn x))
+                  (set! i (+ i 1)))
                 src)
               result)))))))
 
-(define Array {:__callable__ (fn (&rest args) (cond ((= (len args) 0) (list)) ((and (= (len args) 1) (number? (nth args 0))) (js-make-list-of-length (js-num-to-int (nth args 0)) :js-undefined)) (else args))) :prototype {:entries (js-array-proto-fn "entries") :concat (js-array-proto-fn "concat") :lastIndexOf (js-array-proto-fn "lastIndexOf") :splice (js-array-proto-fn "splice") :filter (js-array-proto-fn "filter") :findLast (js-array-proto-fn "findLast") :shift (js-array-proto-fn "shift") :join (js-array-proto-fn "join") :reduceRight (js-array-proto-fn "reduceRight") :values (js-array-proto-fn "values") :reduce (js-array-proto-fn "reduce") :slice (js-array-proto-fn "slice") :includes (js-array-proto-fn "includes") :findLastIndex (js-array-proto-fn "findLastIndex") :find (js-array-proto-fn "find") :toLocaleString (js-array-proto-fn "toLocaleString") :findIndex (js-array-proto-fn "findIndex") :sort (js-array-proto-fn "sort") :every (js-array-proto-fn "every") :indexOf (js-array-proto-fn "indexOf") :unshift (js-array-proto-fn "unshift") :push (js-array-proto-fn "push") :map (js-array-proto-fn "map") :some (js-array-proto-fn "some") :flat (js-array-proto-fn "flat") :toSorted (js-array-proto-fn "toSorted") :at (js-array-proto-fn "at") :pop (js-array-proto-fn "pop") :toReversed (js-array-proto-fn "toReversed") :copyWithin (js-array-proto-fn "copyWithin") :toString (js-array-proto-fn "toString") :forEach (js-array-proto-fn "forEach") :fill (js-array-proto-fn "fill") :flatMap (js-array-proto-fn "flatMap") :keys (js-array-proto-fn "keys") :reverse (js-array-proto-fn "reverse")} :isArray js-array-is-array :of js-array-of :from js-array-from})
+(define Array {:of js-array-of :from js-array-from :isArray js-array-is-array :prototype {:reverse (js-array-proto-fn "reverse") :fill (js-array-proto-fn "fill") :flatMap (js-array-proto-fn "flatMap") :keys (js-array-proto-fn "keys") :forEach (js-array-proto-fn "forEach") :toString (js-array-proto-fn "toString") :copyWithin (js-array-proto-fn "copyWithin") :toReversed (js-array-proto-fn "toReversed") :pop (js-array-proto-fn "pop") :at (js-array-proto-fn "at") :push (js-array-proto-fn "push") :map (js-array-proto-fn "map") :some (js-array-proto-fn "some") :flat (js-array-proto-fn "flat") :toSorted (js-array-proto-fn "toSorted") :indexOf (js-array-proto-fn "indexOf") :unshift (js-array-proto-fn "unshift") :every (js-array-proto-fn "every") :sort (js-array-proto-fn "sort") :findIndex (js-array-proto-fn "findIndex") :toLocaleString (js-array-proto-fn "toLocaleString") :find (js-array-proto-fn "find") :includes (js-array-proto-fn "includes") :findLastIndex (js-array-proto-fn "findLastIndex") :slice (js-array-proto-fn "slice") :reduce (js-array-proto-fn "reduce") :values (js-array-proto-fn "values") :join (js-array-proto-fn "join") :reduceRight (js-array-proto-fn "reduceRight") :shift (js-array-proto-fn "shift") :filter (js-array-proto-fn "filter") :findLast (js-array-proto-fn "findLast") :concat (js-array-proto-fn "concat") :lastIndexOf (js-array-proto-fn "lastIndexOf") :splice (js-array-proto-fn "splice") :entries (js-array-proto-fn "entries")} :__callable__ (fn (&rest args) (cond ((= (len args) 0) (list)) ((and (= (len args) 1) (number? (nth args 0))) (js-make-list-of-length (js-num-to-int (nth args 0)) :js-undefined)) (else args)))})
 
 (dict-set! Array "length" 1)
 
@@ -3431,7 +3569,7 @@
           ((s (cond ((= (type-of this-val) "string") this-val) ((and (= (type-of this-val) "dict") (contains? (keys this-val) "__js_string_value__")) (get this-val "__js_string_value__")) (else "[object Object]"))))
           (js-invoke-method s name args))))))
 
-(define String {:fromCharCode js-string-from-char-code :__callable__ (fn (&rest args) (if (= (len args) 0) "" (js-to-string (nth args 0)))) :prototype {:toLowerCase (js-string-proto-fn "toLowerCase") :concat (js-string-proto-fn "concat") :startsWith (js-string-proto-fn "startsWith") :padEnd (js-string-proto-fn "padEnd") :codePointAt (js-string-proto-fn "codePointAt") :lastIndexOf (js-string-proto-fn "lastIndexOf") :indexOf (js-string-proto-fn "indexOf") :localeCompare (js-string-proto-fn "localeCompare") :split (js-string-proto-fn "split") :endsWith (js-string-proto-fn "endsWith") :trim (js-string-proto-fn "trim") :valueOf (js-string-proto-fn "valueOf") :at (js-string-proto-fn "at") :normalize (js-string-proto-fn "normalize") :substring (js-string-proto-fn "substring") :replaceAll (js-string-proto-fn "replaceAll") :repeat (js-string-proto-fn "repeat") :padStart (js-string-proto-fn "padStart") :search (js-string-proto-fn "search") :toUpperCase (js-string-proto-fn "toUpperCase") :trimEnd (js-string-proto-fn "trimEnd") :toString (js-string-proto-fn "toString") :toLocaleLowerCase (js-string-proto-fn "toLocaleLowerCase") :charCodeAt (js-string-proto-fn "charCodeAt") :slice (js-string-proto-fn "slice") :charAt (js-string-proto-fn "charAt") :match (js-string-proto-fn "match") :includes (js-string-proto-fn "includes") :trimStart (js-string-proto-fn "trimStart") :toLocaleUpperCase (js-string-proto-fn "toLocaleUpperCase") :replace (js-string-proto-fn "replace")} :raw (fn (&rest args) (if (empty? args) "" (js-to-string (nth args 0))))})
+(define String {:raw (fn (&rest args) (if (empty? args) "" (js-to-string (nth args 0)))) :prototype {:replace (js-string-proto-fn "replace") :toLocaleUpperCase (js-string-proto-fn "toLocaleUpperCase") :trimStart (js-string-proto-fn "trimStart") :includes (js-string-proto-fn "includes") :charAt (js-string-proto-fn "charAt") :match (js-string-proto-fn "match") :charCodeAt (js-string-proto-fn "charCodeAt") :slice (js-string-proto-fn "slice") :toString (js-string-proto-fn "toString") :toLocaleLowerCase (js-string-proto-fn "toLocaleLowerCase") :toUpperCase (js-string-proto-fn "toUpperCase") :trimEnd (js-string-proto-fn "trimEnd") :repeat (js-string-proto-fn "repeat") :padStart (js-string-proto-fn "padStart") :search (js-string-proto-fn "search") :substring (js-string-proto-fn "substring") :replaceAll (js-string-proto-fn "replaceAll") :trim (js-string-proto-fn "trim") :valueOf (js-string-proto-fn "valueOf") :at (js-string-proto-fn "at") :normalize (js-string-proto-fn "normalize") :split (js-string-proto-fn "split") :endsWith (js-string-proto-fn "endsWith") :indexOf (js-string-proto-fn "indexOf") :localeCompare (js-string-proto-fn "localeCompare") :toLowerCase (js-string-proto-fn "toLowerCase") :concat (js-string-proto-fn "concat") :startsWith (js-string-proto-fn "startsWith") :padEnd (js-string-proto-fn "padEnd") :codePointAt (js-string-proto-fn "codePointAt") :lastIndexOf (js-string-proto-fn "lastIndexOf")} :__callable__ (fn (&rest args) (if (= (len args) 0) "" (js-to-string (nth args 0)))) :fromCharCode js-string-from-char-code})
 
 (dict-set! String "length" 1)
 
@@ -3528,7 +3666,10 @@
         (let
           ((s (js-to-string (nth args 0)))
             (radix-arg
-              (if (< (len args) 2) 10 (js-to-number (nth args 1)))))
+              (if
+                (< (len args) 2)
+                10
+                (js-to-number (nth args 1)))))
           (let
             ((radix (if (or (js-number-is-nan radix-arg) (= radix-arg 0)) 10 radix-arg)))
             (js-parse-int-str (js-trim s) (js-math-trunc radix))))))))
@@ -3634,13 +3775,20 @@
                 ((prev (char-at s (- i 1))))
                 (if
                   (or (= prev "e") (= prev "E"))
-                  (js-float-prefix-end s (+ i 1) sawdigit sawdot sawe)
+                  (js-float-prefix-end
+                    s
+                    (+ i 1)
+                    sawdigit
+                    sawdot
+                    sawe)
                   i)))
             (else i)))))))
 
 (define
   encodeURIComponent
-  (fn (v) (let ((s (js-to-string v))) (js-uri-encode-loop s 0 ""))))
+  (fn
+    (v)
+    (let ((s (js-to-string v))) (js-uri-encode-loop s 0 ""))))
 
 (define decodeURIComponent (fn (v) (js-to-string v)))
 
@@ -3660,7 +3808,8 @@
           (let
             ((code (char-code c)))
             (cond
-              ((= c " ") (js-uri-encode-loop s (+ i 1) (str acc "%20")))
+              ((= c " ")
+                (js-uri-encode-loop s (+ i 1) (str acc "%20")))
               ((and (>= code 48) (<= code 57))
                 (js-uri-encode-loop s (+ i 1) (str acc c)))
               ((and (>= code 65) (<= code 90))
@@ -3670,7 +3819,10 @@
               ((or (= c "-") (= c "_") (= c ".") (= c "~") (= c "!") (= c "*") (= c "'") (= c "(") (= c ")"))
                 (js-uri-encode-loop s (+ i 1) (str acc c)))
               (else
-                (js-uri-encode-loop s (+ i 1) (str acc "%" (js-hex-2 code)))))))))))
+                (js-uri-encode-loop
+                  s
+                  (+ i 1)
+                  (str acc "%" (js-hex-2 code)))))))))))
 
 (define
   js-hex-2
@@ -3684,7 +3836,9 @@
   js-hex-digit
   (fn
     (d)
-    (cond ((< d 10) (js-to-string d)) (else (js-code-to-char (+ 55 d))))))
+    (cond
+      ((< d 10) (js-to-string d))
+      (else (js-code-to-char (+ 55 d))))))
 
 (define
   js-json-stringify
@@ -3750,11 +3904,16 @@
       (let
         ((c (char-at s i)))
         (cond
-          ((= c "\"") (js-json-escape-loop s (+ i 1) (str acc "\\\"")))
-          ((= c "\\") (js-json-escape-loop s (+ i 1) (str acc "\\\\")))
-          ((= c "\n") (js-json-escape-loop s (+ i 1) (str acc "\\n")))
-          ((= c "\r") (js-json-escape-loop s (+ i 1) (str acc "\\r")))
-          ((= c "\t") (js-json-escape-loop s (+ i 1) (str acc "\\t")))
+          ((= c "\"")
+            (js-json-escape-loop s (+ i 1) (str acc "\\\"")))
+          ((= c "\\")
+            (js-json-escape-loop s (+ i 1) (str acc "\\\\")))
+          ((= c "\n")
+            (js-json-escape-loop s (+ i 1) (str acc "\\n")))
+          ((= c "\r")
+            (js-json-escape-loop s (+ i 1) (str acc "\\r")))
+          ((= c "\t")
+            (js-json-escape-loop s (+ i 1) (str acc "\\t")))
           (else (js-json-escape-loop s (+ i 1) (str acc c))))))))
 
 (define
@@ -3794,9 +3953,12 @@
         ((= (char-at s i) "\"") (js-json-parse-string st))
         ((= (char-at s i) "[") (js-json-parse-array st))
         ((= (char-at s i) "{") (js-json-parse-object st))
-        ((= (char-at s i) "t") (begin (dict-set! st "i" (+ i 4)) true))
-        ((= (char-at s i) "f") (begin (dict-set! st "i" (+ i 5)) false))
-        ((= (char-at s i) "n") (begin (dict-set! st "i" (+ i 4)) nil))
+        ((= (char-at s i) "t")
+          (begin (dict-set! st "i" (+ i 4)) true))
+        ((= (char-at s i) "f")
+          (begin (dict-set! st "i" (+ i 5)) false))
+        ((= (char-at s i) "n")
+          (begin (dict-set! st "i" (+ i 4)) nil))
         (else (js-json-parse-number st))))))
 
 (define
@@ -3935,7 +4097,7 @@
           ((= c "}") (dict-set! st "i" (+ (get st "i") 1)))
           (else (error "JSON: expected , or }")))))))
 
-(define JSON {:parse js-json-parse :stringify js-json-stringify})
+(define JSON {:stringify js-json-stringify :parse js-json-parse})
 
 (define
   js-promise-flush-callbacks!
@@ -4038,7 +4200,11 @@
     (p args)
     (let
       ((on-f (if (>= (len args) 1) (nth args 0) :js-undefined))
-        (on-r (if (>= (len args) 2) (nth args 1) :js-undefined)))
+        (on-r
+          (if
+            (>= (len args) 2)
+            (nth args 1)
+            :js-undefined)))
       (js-promise-then-internal! p on-f on-r))))
 
 (define
@@ -4137,7 +4303,9 @@
     (cond
       ((<= n 0) acc)
       (else
-        (begin (append! acc fill) (js-make-list-loop acc (- n 1) fill))))))
+        (begin
+          (append! acc fill)
+          (js-make-list-loop acc (- n 1) fill))))))
 
 (define
   js-promise-all-loop!
@@ -4157,7 +4325,10 @@
                 (let
                   ((results (get state "results")))
                   (set-nth! results i v)
-                  (dict-set! state "remaining" (- (get state "remaining") 1))
+                  (dict-set!
+                    state
+                    "remaining"
+                    (- (get state "remaining") 1))
                   (cond
                     ((= (get state "remaining") 0)
                       (js-promise-resolve! result-p results))
@@ -4173,7 +4344,8 @@
       ((items (if (empty? args) (list) (first args)))
         (p (js-make-promise)))
       (cond
-        ((= (len items) 0) (begin (js-promise-resolve! p (list)) p))
+        ((= (len items) 0)
+          (begin (js-promise-resolve! p (list)) p))
         (else
           (let
             ((n (len items)) (state (dict)))
@@ -4332,7 +4504,11 @@
       ((= name "test")
         (let
           ((impl (get __js_regex_platform__ "test"))
-            (arg (if (= (len args) 0) "" (js-to-string (nth args 0)))))
+            (arg
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0)))))
           (if
             (js-undefined? impl)
             (js-regex-stub-test rx arg)
@@ -4340,7 +4516,11 @@
       ((= name "exec")
         (let
           ((impl (get __js_regex_platform__ "exec"))
-            (arg (if (= (len args) 0) "" (js-to-string (nth args 0)))))
+            (arg
+              (if
+                (= (len args) 0)
+                ""
+                (js-to-string (nth args 0)))))
           (if
             (js-undefined? impl)
             (js-regex-stub-exec rx arg)
@@ -4349,4 +4529,11 @@
         (str "/" (get rx "source") "/" (get rx "flags")))
       (else js-undefined))))
 
-(define js-global {:isFinite js-global-is-finite :console console :Number Number :parseFloat parseFloat :Math Math :Array Array :Boolean Boolean :String String :NaN 0 :Infinity inf :isNaN js-global-is-nan :Object Object :parseInt parseInt :JSON JSON :undefined js-undefined})
+(begin
+  (dict-set! Object "__proto__" (get js-function-global "prototype"))
+  (dict-set! Array "__proto__" (get js-function-global "prototype"))
+  (dict-set! Number "__proto__" (get js-function-global "prototype"))
+  (dict-set! String "__proto__" (get js-function-global "prototype"))
+  (dict-set! Boolean "__proto__" (get js-function-global "prototype")))
+
+(define js-global {:undefined js-undefined :JSON JSON :parseInt parseInt :Object Object :isNaN js-global-is-nan :Infinity inf :NaN 0 :String String :Boolean Boolean :Array Array :Math Math :parseFloat parseFloat :Number Number :console console :isFinite js-global-is-finite})
diff --git a/lib/js/test262-scoreboard.json b/lib/js/test262-scoreboard.json
index e52d87a4..753f9b70 100644
--- a/lib/js/test262-scoreboard.json
+++ b/lib/js/test262-scoreboard.json
@@ -1,26 +1,26 @@
 {
   "totals": {
-    "pass": 77,
-    "fail": 16,
+    "pass": 78,
+    "fail": 15,
     "skip": 1,
     "timeout": 6,
     "total": 100,
     "runnable": 99,
-    "pass_rate": 77.8
+    "pass_rate": 78.8
   },
   "categories": [
     {
       "category": "built-ins/String",
       "total": 100,
-      "pass": 77,
-      "fail": 16,
+      "pass": 78,
+      "fail": 15,
       "skip": 1,
       "timeout": 6,
-      "pass_rate": 77.8,
+      "pass_rate": 78.8,
       "top_failures": [
         [
           "Test262Error (assertion failed)",
-          14
+          13
         ],
         [
           "Timeout",
@@ -40,7 +40,7 @@
   "top_failure_modes": [
     [
       "Test262Error (assertion failed)",
-      14
+      13
     ],
     [
       "Timeout",
@@ -56,6 +56,6 @@
     ]
   ],
   "pinned_commit": "d5e73fc8d2c663554fb72e2380a8c2bc1a318a33",
-  "elapsed_seconds": 250.0,
+  "elapsed_seconds": 273.6,
   "workers": 1
 }
\ No newline at end of file
diff --git a/lib/js/test262-scoreboard.md b/lib/js/test262-scoreboard.md
index d9417b28..385613d2 100644
--- a/lib/js/test262-scoreboard.md
+++ b/lib/js/test262-scoreboard.md
@@ -1,13 +1,13 @@
 # test262 scoreboard
 
 Pinned commit: `d5e73fc8d2c663554fb72e2380a8c2bc1a318a33`
-Wall time: 250.0s
+Wall time: 273.6s
 
-**Total:** 77/99 runnable passed (77.8%). Raw: pass=77 fail=16 skip=1 timeout=6 total=100.
+**Total:** 78/99 runnable passed (78.8%). Raw: pass=78 fail=15 skip=1 timeout=6 total=100.
 
 ## Top failure modes
 
-- **14x** Test262Error (assertion failed)
+- **13x** Test262Error (assertion failed)
 - **6x** Timeout
 - **1x** ReferenceError (undefined symbol)
 - **1x** SyntaxError (parse/unsupported syntax)
@@ -16,13 +16,13 @@ Wall time: 250.0s
 
 | Category | Pass | Fail | Skip | Timeout | Total | Pass % |
 |---|---:|---:|---:|---:|---:|---:|
-| built-ins/String | 77 | 16 | 1 | 6 | 100 | 77.8% |
+| built-ins/String | 78 | 15 | 1 | 6 | 100 | 78.8% |
 
 ## Per-category top failures (min 10 runnable, worst first)
 
-### built-ins/String  (77/99 — 77.8%)
+### built-ins/String  (78/99 — 78.8%)
 
-- **14x** Test262Error (assertion failed)
+- **13x** Test262Error (assertion failed)
 - **6x** Timeout
 - **1x** ReferenceError (undefined symbol)
 - **1x** SyntaxError (parse/unsupported syntax)
diff --git a/plans/js-on-sx.md b/plans/js-on-sx.md
index eef5a9b6..cc919152 100644
--- a/plans/js-on-sx.md
+++ b/plans/js-on-sx.md
@@ -158,6 +158,8 @@ Each item: implement → tests → update progress. Mark `[x]` when tests green.
 
 Append-only record of completed iterations. Loop writes one line per iteration: date, what was done, test count delta.
 
+- 2026-05-07 — **Constructors (`Object`/`Array`/`Number`/`String`/`Boolean`) carry `__proto__ = Function.prototype`.** Per spec, the constructors are functions and inherit from `Function.prototype`, so `Function.prototype.foo = 1; Array.foo === 1`. Previously the constructor dicts had no `__proto__`, so they only saw `Object.prototype` via the recent fallback — `Function.prototype` mutations were invisible. Added a `(begin (dict-set! ...))` post-init at the end of `runtime.sx` after the constructors are defined. Combined with the existing Object.prototype fallback, the proto chain now terminates correctly for the constructor → `Function.prototype` → `Object.prototype` walk. built-ins/Number: 41/50 → 42/50, built-ins/String: 75/99 → 78/99, built-ins/Array: 12/45 → 13/45. conformance.sh: 148/148.
+
 - 2026-05-07 — **`js-neg` preserves IEEE-754 negative zero.** `-0` was returning `0` (rational integer) because `js-neg` did `(- 0 (js-to-number a))`, which loses sign-of-zero in any arithmetic implementation that follows IEEE 754. Per JS spec, `-0` and `1/-0 === -Infinity` must be observable. Switched to `(* -1 (exact->inexact (js-to-number a)))` so the result is always a float and `-0.0` is preserved. Fixes `Math.asinh(-0)` and other `-0`-sensitive tests; `1/(-0) === -Infinity` now works. built-ins/Math: 41/45 → 42/45. conformance.sh: 148/148.
 
 - 2026-05-07 — **`js-div` coerces divisor to inexact before dividing.** When both operands are SX rationals (e.g. `(js-div 1 0)` from JS-transpiled `1/0` reaching the harness's `_isSameValue` +0/-0 check), SX integer-rational division throws "rational: division by zero" instead of producing JS `Infinity`. Wrapped the divisor in `(exact->inexact ...)` so it's always a float; integer-by-zero now returns `inf` (positive numerator), `-inf` (negative), `nan` (zero numerator), matching JS semantics. Was hitting harness assertion failures even when the test value matched expected. built-ins/Number: 37/50 → 41/50. built-ins/String: 77/99. conformance.sh: 148/148.