Bug 1670033 - Part 7: Implement "unit" support for the "Intl Enumerat…

…ion API" proposal. r=tcampbell

Differential Revision: https://phabricator.services.mozilla.com/D120607

js/src/builtin/intl/IntlObject.cpp

@@ -24,6 +24,7 @@
 #include "builtin/intl/DateTimeFormat.h"
 #include "builtin/intl/FormatBuffer.h"
 #include "builtin/intl/LanguageTag.h"
+#include "builtin/intl/MeasureUnitGenerated.h"
 #include "builtin/intl/NumberFormat.h"
 #include "builtin/intl/NumberingSystemsGenerated.h"
 #include "builtin/intl/PluralRules.h"
@@ -1232,6 +1233,25 @@ static ArrayObject* AvailableTimeZones(JSContext* cx) {
   return CreateArrayFromList(cx, &timeZones);
 }
 
+template <size_t N>
+constexpr auto MeasurementUnitNames(const MeasureUnit (&units)[N]) {
+  std::array<const char*, N> array = {};
+  for (size_t i = 0; i < N; ++i) {
+    array[i] = units[i].name;
+  }
+  return array;
+}
+
+/**
+ * AvailableUnits ( )
+ */
+static ArrayObject* AvailableUnits(JSContext* cx) {
+  static constexpr auto simpleMeasureUnitNames =
+      MeasurementUnitNames(simpleMeasureUnits);
+
+  return CreateArrayFromSortedList(cx, simpleMeasureUnitNames);
+}
+
 bool js::intl_SupportedValuesOf(JSContext* cx, unsigned argc, JS::Value* vp) {
   CallArgs args = CallArgsFromVp(argc, vp);
   MOZ_ASSERT(args.length() == 1);
@@ -1253,6 +1273,8 @@ bool js::intl_SupportedValuesOf(JSContext* cx, unsigned argc, JS::Value* vp) {
     list = AvailableNumberingSystems(cx);
   } else if (StringEqualsLiteral(key, "timeZone")) {
     list = AvailableTimeZones(cx);
+  } else if (StringEqualsLiteral(key, "unit")) {
+    list = AvailableUnits(cx);
   } else {
     ReportBadKey(cx, key);
     return false;

js/src/tests/non262/Intl/supportedValuesOf-unit.js

@@ -0,0 +1,20 @@
+// |reftest| skip-if(!this.hasOwnProperty("Intl"))
+
+const units = Intl.supportedValuesOf("unit");
+
+assertEq(new Set(units).size, units.length, "No duplicates are present");
+assertEqArray(units, [...units].sort(), "The list is sorted");
+
+const unitRE = /^[a-z]+(-[a-z]+)*$/;
+for (let unit of units) {
+  assertEq(unitRE.test(unit), true, `${unit} is ASCII lower-case, separated by hyphens`);
+  assertEq(unit.includes("-per-"), false, `${unit} is a simple unit identifier`);
+}
+
+for (let unit of units) {
+  let obj = new Intl.NumberFormat("en", {style: "unit", unit});
+  assertEq(obj.resolvedOptions().unit, unit, `${unit} is supported by NumberFormat`);
+}
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);