From 0b4030fdd9a320ce3f0190be4cd5b216dd89a9a8 Mon Sep 17 00:00:00 2001
From: "Artem S. Povalyukhin" <artem.povaluhin@gmail.com>
Date: Fri, 26 Jul 2019 07:24:36 +0300
Subject: [PATCH] Fixed Array.length setter.

This closes #26 and closes #27 issues on Github.
---
 njs/njs_array.c          | 21 ++++++++++++++-------
 njs/test/njs_unit_test.c | 20 ++++++++++++++++++++
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/njs/njs_array.c b/njs/njs_array.c
index 7b43153f..dbeb0014 100644
--- a/njs/njs_array.c
+++ b/njs/njs_array.c
@@ -318,10 +318,11 @@ njs_array_length(njs_vm_t *vm, njs_value_t *value, njs_value_t *setval,
     njs_value_t  *val;
     njs_array_t  *array;
     njs_object_t *proto;
+    njs_value_t  val_length;
 
     proto = njs_object(value);
 
-    if (setval == NULL) {
+    if (nxt_fast_path(setval == NULL)) {
         do {
             if (nxt_fast_path(proto->type == NJS_ARRAY)) {
                 break;
@@ -345,13 +346,19 @@ njs_array_length(njs_vm_t *vm, njs_value_t *value, njs_value_t *setval,
         return NJS_DECLINED;
     }
 
-    if (!njs_is_number(setval)) {
-        njs_range_error(vm, "Invalid array length");
-        return NJS_ERROR;
+    if (nxt_slow_path(!njs_is_number(setval))) {
+        ret = njs_value_to_numeric(vm, &val_length, setval);
+        if (ret != NXT_OK) {
+            return ret;
+        }
+
+        num = njs_number(&val_length);
+
+    } else {
+        num = njs_number(setval);
     }
 
-    num = njs_number(setval);
-    length = (uint32_t) num;
+    length = njs_number_to_uint32(num);
 
     if ((double) length != num) {
         njs_range_error(vm, "Invalid array length");
@@ -379,7 +386,7 @@ njs_array_length(njs_vm_t *vm, njs_value_t *value, njs_value_t *setval,
 
     array->length = length;
 
-    njs_set_number(retval, length);
+    *retval = *setval;
     return NJS_OK;
 }
 
diff --git a/njs/test/njs_unit_test.c b/njs/test/njs_unit_test.c
index b0d5b669..dcf35a2b 100644
--- a/njs/test/njs_unit_test.c
+++ b/njs/test/njs_unit_test.c
@@ -3531,6 +3531,26 @@ static njs_unit_test_t  njs_test[] =
     { nxt_string("[].length = -1"),
       nxt_string("RangeError: Invalid array length") },
 
+    { nxt_string("var a = [1];"
+                 "typeof (a.length = '') == 'string' && a.length == 0"),
+      nxt_string("true") },
+
+    { nxt_string("var a = [1]; "
+                 "typeof (a.length = Object(2)) == 'object' && a.length == 2"),
+      nxt_string("true") },
+
+    { nxt_string("var a = [1]; "
+                 "typeof (a.length = Object('2')) == 'object'"),
+      nxt_string("true") },
+
+    { nxt_string("var a = [1]; "
+                 "a.length = { valueOf: () => 2 }; a.length == 2"),
+      nxt_string("true") },
+
+    { nxt_string("var a = [1]; "
+                 "a.length = { toString: () => '2' }; a.length == 2"),
+      nxt_string("true") },
+
     { nxt_string("var a = []; a.length = 0; JSON.stringify(a)"),
       nxt_string("[]") },
 
-- 
2.47.3