1 files changed, 133 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testNumberToString.cpp b/js/src/jsapi-tests/testNumberToString.cpp
new file mode 100644
index 0000000000..d5107327c6
--- /dev/null
+++ b/js/src/jsapi-tests/testNumberToString.cpp
@@ -0,0 +1,133 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ */
+/* 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/. */
+
+#include "mozilla/FloatingPoint.h"  // mozilla::{PositiveInfinity,UnspecifiedNaN}
+
+#include <stddef.h>  // size_t
+#include <string.h>  // memcmp, memset
+
+#include "js/Conversions.h"  // JS::NumberToString, JS::MaximumNumberToStringLength
+#include "jsapi-tests/tests.h"  // BEGIN_TEST, CHECK_EQUAL, END_TEST
+#include "util/Text.h"          // js_strlen
+
+#define REST(x) x, (js_strlen(x)), __LINE__
+
+static const struct NumberToStringTest {
+  double number;
+  const char* expected;
+  size_t expectedLength;
+  size_t lineno;
+} numberToStringTests[] = {
+    {5e-324, REST("5e-324")},                          // 2**-1074
+    {9.5367431640625e-7, REST("9.5367431640625e-7")},  // 2**-20
+    {0.0000010984284297360395, REST("0.0000010984284297360395")},
+    {0.0000019073486328125, REST("0.0000019073486328125")},  // 2**-19
+    {0.000003814697265625, REST("0.000003814697265625")},    // 2**-18
+    {0.0000057220458984375, REST("0.0000057220458984375")},  // 2**-18 + 2**-19
+    {0.000244140625, REST("0.000244140625")},                // 2**-12
+    {0.125, REST("0.125")},
+    {0.25, REST("0.25")},
+    {0.5, REST("0.5")},
+    {1, REST("1")},
+    {1.5, REST("1.5")},
+    {2, REST("2")},
+    {9, REST("9")},
+    {10, REST("10")},
+    {15, REST("15")},
+    {16, REST("16")},
+    {389427, REST("389427")},
+    {1073741823, REST("1073741823")},
+    {1073741824, REST("1073741824")},
+    {1073741825, REST("1073741825")},
+    {2147483647, REST("2147483647")},
+    {2147483648, REST("2147483648")},
+    {2147483649, REST("2147483649")},
+    {4294967294, REST("4294967294")},
+    {4294967295, REST("4294967295")},
+    {4294967296, REST("4294967296")},
+    {999999999999999900000.0, REST("999999999999999900000")},
+    {999999999999999900000.0 + 65535, REST("999999999999999900000")},
+    {999999999999999900000.0 + 65536, REST("1e+21")},
+    {1.7976931348623157e+308, REST("1.7976931348623157e+308")},  // MAX_VALUE
+};
+
+static constexpr char PoisonChar = 0x37;
+
+struct StorageForNumberToString {
+  char out[JS::MaximumNumberToStringLength];
+  char overflow;
+} storage;
+
+BEGIN_TEST(testNumberToString) {
+  StorageForNumberToString storage;
+
+  if (!testNormalValues(false, storage)) {
+    return false;
+  }
+
+  if (!testNormalValues(true, storage)) {
+    return false;
+  }
+
+  NumberToStringTest zeroTest = {0.0, REST("0")};
+  if (!testOne(zeroTest, false, storage)) {
+    return false;
+  }
+  NumberToStringTest negativeZeroTest = {-0.0, REST("0")};
+  if (!testOne(negativeZeroTest, false, storage)) {
+    return false;
+  }
+
+  NumberToStringTest infTest = {mozilla::PositiveInfinity<double>(),
+                                REST("Infinity")};
+  if (!testOne(infTest, false, storage)) {
+    return false;
+  }
+  if (!testOne(infTest, true, storage)) {
+    return false;
+  }
+
+  NumberToStringTest nanTest = {mozilla::UnspecifiedNaN<double>(), REST("NaN")};
+  return testOne(nanTest, false, storage);
+}
+
+bool testNormalValues(bool hasMinusSign, StorageForNumberToString& storage) {
+  for (const auto& test : numberToStringTests) {
+    if (!testOne(test, hasMinusSign, storage)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool testOne(const NumberToStringTest& test, bool hasMinusSign,
+             StorageForNumberToString& storage) {
+  memset(&storage, PoisonChar, sizeof(storage));
+
+  JS::NumberToString(hasMinusSign ? -test.number : test.number, storage.out);
+
+  CHECK_EQUAL(storage.overflow, PoisonChar);
+
+  const char* start = storage.out;
+  if (hasMinusSign) {
+    CHECK_EQUAL(start[0], '-');
+    start++;
+  }
+
+  if (!checkEqual(memcmp(start, test.expected, test.expectedLength), 0, start,
+                  test.expected, __FILE__, test.lineno)) {
+    return false;
+  }
+
+  char actualTerminator[] = {start[test.expectedLength], '\0'};
+  return checkEqual(actualTerminator[0], '\0', actualTerminator, "'\\0'",
+                    __FILE__, test.lineno);
+}
+END_TEST(testNumberToString)
+
+#undef REST