[intl] Impl ECMA402 PR 471 rounding behavior

Fix awkward rounding behavior
Change Intl::SetNumberFormatDigitOptions to fix the awkward rounding
behavior in NumberFormat when formatting a currency with
"maximumFractionDigits" set to a value less than 2.

Bug: v8:10844
Change-Id: I2ff4afa9f747cd79cb9964fe4c77a0dd2b8977b5
Refs: tc39/ecma402#471
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2442191
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70270}

src/objects/intl-objects.cc

@@ -24,6 +24,7 @@
 #include "src/objects/js-number-format-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/property-descriptor.h"
+#include "src/objects/smi.h"
 #include "src/objects/string.h"
 #include "src/strings/string-case.h"
 #include "unicode/basictz.h"
@@ -1275,28 +1276,72 @@ Maybe<Intl::NumberFormatDigitOptions> Intl::SetNumberFormatDigitOptions(
 
     // 15. Else If mnfd is not undefined or mxfd is not undefined, then
     if (!mnfd_obj->IsUndefined(isolate) || !mxfd_obj->IsUndefined(isolate)) {
-      // 15. b. Let mnfd be ? DefaultNumberOption(mnfd, 0, 20, mnfdDefault).
+      Handle<String> mxfd_str = factory->maximumFractionDigits_string();
       Handle<String> mnfd_str = factory->minimumFractionDigits_string();
-      if (!DefaultNumberOption(isolate, mnfd_obj, 0, 20, mnfd_default, mnfd_str)
-               .To(&mnfd)) {
+
+      int specified_mnfd;
+      int specified_mxfd;
+
+      // a. Let _specifiedMnfd_ be ? DefaultNumberOption(_mnfd_, 0, 20,
+      // *undefined*).
+      if (!DefaultNumberOption(isolate, mnfd_obj, 0, 20, -1, mnfd_str)
+               .To(&specified_mnfd)) {
+        return Nothing<NumberFormatDigitOptions>();
+      }
+      Handle<Object> specifiedMnfd_obj;
+      if (specified_mnfd < 0) {
+        specifiedMnfd_obj = factory->undefined_value();
+      } else {
+        specifiedMnfd_obj = handle(Smi::FromInt(specified_mnfd), isolate);
+      }
+
+      // b.  Let _specifiedMxfd_ be ? DefaultNumberOption(_mxfd_, 0, 20,
+      // *undefined*).
+      if (!DefaultNumberOption(isolate, mxfd_obj, 0, 20, -1, mxfd_str)
+               .To(&specified_mxfd)) {
         return Nothing<NumberFormatDigitOptions>();
       }
+      Handle<Object> specifiedMxfd_obj;
+      if (specified_mxfd < 0) {
+        specifiedMxfd_obj = factory->undefined_value();
+      } else {
+        specifiedMxfd_obj = handle(Smi::FromInt(specified_mxfd), isolate);
+      }
 
-      // 15. c. Let mxfdActualDefault be max( mnfd, mxfdDefault ).
-      int mxfd_actual_default = std::max(mnfd, mxfd_default);
+      // c. If _specifiedMxfd_ is not *undefined*, set _mnfdDefault_ to
+      // min(_mnfdDefault_, _specifiedMxfd_).
+      if (specified_mxfd >= 0) {
+        mnfd_default = std::min(mnfd_default, specified_mxfd);
+      }
 
-      // 15. d. Let mxfd be ? DefaultNumberOption(mxfd, mnfd, 20,
-      // mxfdActualDefault).
-      Handle<String> mxfd_str = factory->maximumFractionDigits_string();
-      if (!DefaultNumberOption(isolate, mxfd_obj, mnfd, 20, mxfd_actual_default,
-                               mxfd_str)
+      // d. Set _mnfd_ to ! DefaultNumberOption(_specifiedMnfd_, 0, 20,
+      // _mnfdDefault_).
+      if (!DefaultNumberOption(isolate, specifiedMnfd_obj, 0, 20, mnfd_default,
+                               mnfd_str)
+               .To(&mnfd)) {
+        return Nothing<NumberFormatDigitOptions>();
+      }
+
+      // e. Set _mxfd_ to ! DefaultNumberOption(_specifiedMxfd_, 0, 20,
+      // max(_mxfdDefault_, _mnfd_)).
+      if (!DefaultNumberOption(isolate, specifiedMxfd_obj, 0, 20,
+                               std::max(mxfd_default, mnfd), mxfd_str)
                .To(&mxfd)) {
         return Nothing<NumberFormatDigitOptions>();
       }
-      // 15. e. Set intlObj.[[MinimumFractionDigits]] to mnfd.
+
+      // f. If _mnfd_ is greater than _mxfd_, throw a *RangeError* exception.
+      if (mnfd > mxfd) {
+        THROW_NEW_ERROR_RETURN_VALUE(
+            isolate,
+            NewRangeError(MessageTemplate::kPropertyValueOutOfRange, mxfd_str),
+            Nothing<NumberFormatDigitOptions>());
+      }
+
+      // g. Set intlObj.[[MinimumFractionDigits]] to mnfd.
       digit_options.minimum_fraction_digits = mnfd;
 
-      // 15. f. Set intlObj.[[MaximumFractionDigits]] to mxfd.
+      // h. Set intlObj.[[MaximumFractionDigits]] to mxfd.
       digit_options.maximum_fraction_digits = mxfd;
       // Else If intlObj.[[Notation]] is "compact", then
     } else if (notation_is_compact) {

test/intl/number-format/check-minimum-fraction-digits.js

@@ -55,3 +55,12 @@ nf = new Intl.NumberFormat('en', {maximumFractionDigits: 3, style: 'currency', c
 assertEquals("$54,306.405", nf.format(54306.4047970));
 assertEquals("$54,306.40", nf.format(54306.4));
 assertEquals("$54,306.00", nf.format(54306));
+
+nf = new Intl.NumberFormat('en', {maximumFractionDigits: 0, style: 'currency', currency: 'USD'});
+
+assertEquals("$54,306", nf.format(54306.4047970));
+assertEquals("$54,306", nf.format(54306.4));
+assertEquals("$54,306", nf.format(54306));
+
+assertThrows(() => new Intl.NumberFormat('en',
+      {minimumFractionDigits: 1, maximumFractionDigits: 0, style: 'currency', currency: 'USD'}));

test/test262/test262.status

@@ -533,7 +533,7 @@
   # https://bugs.chromium.org/p/v8/issues/detail?id=7472
   'intl402/NumberFormat/currency-digits': [FAIL],
 
-  # http://crbug/v8/10844
+  # https://github.com/tc39/test262/pull/2830
   'intl402/NumberFormat/dft-currency-mnfd-range-check-mxfd': [FAIL],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=7831