1 files changed, 99 insertions, 0 deletions
diff --git a/js/src/builtin/Number.js b/js/src/builtin/Number.js
new file mode 100644
index 0000000000..dd0aee8374
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+++ b/js/src/builtin/Number.js
@@ -0,0 +1,99 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#if JS_HAS_INTL_API
+var numberFormatCache = new Record();
+
+/**
+ * Format this Number object into a string, using the locale and formatting options
+ * provided.
+ *
+ * Spec: ECMAScript Language Specification, 5.1 edition, 15.7.4.3.
+ * Spec: ECMAScript Internationalization API Specification, 13.2.1.
+ */
+function Number_toLocaleString() {
+    // Steps 1-2.
+    var x = callFunction(ThisNumberValueForToLocaleString, this);
+
+    // Steps 2-3.
+    var locales = arguments.length > 0 ? arguments[0] : undefined;
+    var options = arguments.length > 1 ? arguments[1] : undefined;
+
+    // Step 4.
+    var numberFormat;
+    if (locales === undefined && options === undefined) {
+        // This cache only optimizes for the old ES5 toLocaleString without
+        // locales and options.
+        if (!IsRuntimeDefaultLocale(numberFormatCache.runtimeDefaultLocale)) {
+            numberFormatCache.numberFormat = intl_NumberFormat(locales, options);
+            numberFormatCache.runtimeDefaultLocale = RuntimeDefaultLocale();
+        }
+        numberFormat = numberFormatCache.numberFormat;
+    } else {
+        numberFormat = intl_NumberFormat(locales, options);
+    }
+
+    // Step 5.
+    return intl_FormatNumber(numberFormat, x, /* formatToParts = */ false, /* unitStyle = */ false);
+}
+#endif  // JS_HAS_INTL_API
+
+// ES6 draft ES6 20.1.2.4
+function Number_isFinite(num) {
+    if (typeof num !== "number")
+        return false;
+    return num - num === 0;
+}
+
+// ES6 draft ES6 20.1.2.2
+function Number_isNaN(num) {
+    if (typeof num !== "number")
+        return false;
+    return num !== num;
+}
+
+// ES2021 draft rev 889f2f30cf554b7ed812c0984626db1c8a4997c7
+// 20.1.2.3 Number.isInteger ( number )
+function Number_isInteger(number) {
+    // Step 1. (Inlined call to IsIntegralNumber)
+
+    // 7.2.6 IsIntegralNumber, step 1.
+    if (typeof number !== "number")
+        return false;
+
+    var integer = std_Math_trunc(number);
+
+    // 7.2.6 IsIntegralNumber, steps 2-4.
+    // |number - integer| ensures Infinity correctly returns false, because
+    // |Infinity - Infinity| yields NaN.
+    return number - integer === 0;
+}
+
+// ES2021 draft rev 889f2f30cf554b7ed812c0984626db1c8a4997c7
+// 20.1.2.5 Number.isSafeInteger ( number )
+function Number_isSafeInteger(number) {
+    // Step 1. (Inlined call to IsIntegralNumber)
+
+    // 7.2.6 IsIntegralNumber, step 1.
+    if (typeof number !== "number")
+        return false;
+
+    var integer = std_Math_trunc(number);
+
+    // 7.2.6 IsIntegralNumber, steps 2-4.
+    // |number - integer| to handle the Infinity case correctly.
+    if (number - integer !== 0)
+        return false;
+
+    // Steps 1.a, 2.
+    return -((2 ** 53) - 1) <= integer && integer <= (2 ** 53) - 1;
+}
+
+function Global_isNaN(number) {
+    return Number_isNaN(ToNumber(number));
+}
+
+function Global_isFinite(number) {
+    return Number_isFinite(ToNumber(number));
+}