Source/JavaScriptCore/runtime/IntlRelativeTimeFormat.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2020 Sony Interactive Entertainment Inc.
  * Copyright (C) 2021 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "IntlRelativeTimeFormat.h"

 #include "IntlNumberFormatInlines.h"
 #include "IntlObjectInlines.h"
 #include "JSCInlines.h"
 #include "ObjectConstructor.h"
 #include <wtf/unicode/icu/ICUHelpers.h>

 namespace JSC {

 const ClassInfo IntlRelativeTimeFormat::s_info = { "Object", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(IntlRelativeTimeFormat) };

 namespace IntlRelativeTimeFormatInternal {
 }

 IntlRelativeTimeFormat* IntlRelativeTimeFormat::create(VM& vm, Structure* structure)
 {
     auto* format = new (NotNull, allocateCell<IntlRelativeTimeFormat>(vm.heap)) IntlRelativeTimeFormat(vm, structure);
     format->finishCreation(vm);
     return format;
 }

 Structure* IntlRelativeTimeFormat::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
 {
     return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
 }

 IntlRelativeTimeFormat::IntlRelativeTimeFormat(VM& vm, Structure* structure)
     : Base(vm, structure)
 {
 }

 void IntlRelativeTimeFormat::finishCreation(VM& vm)
 {
     Base::finishCreation(vm);
     ASSERT(inherits(vm, info()));
 }

 template<typename Visitor>
 void IntlRelativeTimeFormat::visitChildrenImpl(JSCell* cell, Visitor& visitor)
 {
     auto* thisObject = jsCast<IntlRelativeTimeFormat*>(cell);
     ASSERT_GC_OBJECT_INHERITS(thisObject, info());

     Base::visitChildren(thisObject, visitor);
 }

 DEFINE_VISIT_CHILDREN(IntlRelativeTimeFormat);

 Vector<String> IntlRelativeTimeFormat::localeData(const String& locale, RelevantExtensionKey key)
 {
     ASSERT_UNUSED(key, key == RelevantExtensionKey::Nu);
     return numberingSystemsForLocale(locale);
 }

 // https://tc39.es/ecma402/#sec-InitializeRelativeTimeFormat
 void IntlRelativeTimeFormat::initializeRelativeTimeFormat(JSGlobalObject* globalObject, JSValue locales, JSValue optionsValue)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     Vector<String> requestedLocales = canonicalizeLocaleList(globalObject, locales);
     RETURN_IF_EXCEPTION(scope, void());

     JSObject* options = intlCoerceOptionsToObject(globalObject, optionsValue);
     RETURN_IF_EXCEPTION(scope, void());

     ResolveLocaleOptions localeOptions;
     LocaleMatcher localeMatcher = intlOption<LocaleMatcher>(globalObject, options, vm.propertyNames->localeMatcher, { { "lookup"_s, LocaleMatcher::Lookup }, { "best fit"_s, LocaleMatcher::BestFit } }, "localeMatcher must be either \"lookup\" or \"best fit\""_s, LocaleMatcher::BestFit);
     RETURN_IF_EXCEPTION(scope, void());

     String numberingSystem = intlStringOption(globalObject, options, vm.propertyNames->numberingSystem, { }, nullptr, nullptr);
     RETURN_IF_EXCEPTION(scope, void());
     if (!numberingSystem.isNull()) {
         if (!isUnicodeLocaleIdentifierType(numberingSystem)) {
             throwRangeError(globalObject, scope, "numberingSystem is not a well-formed numbering system value"_s);
             return;
         }
         localeOptions[static_cast<unsigned>(RelevantExtensionKey::Nu)] = numberingSystem;
     }

     const auto& availableLocales = intlRelativeTimeFormatAvailableLocales();
     auto resolved = resolveLocale(globalObject, availableLocales, requestedLocales, localeMatcher, localeOptions, { RelevantExtensionKey::Nu }, localeData);
     m_locale = resolved.locale;
     if (m_locale.isEmpty()) {
         throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat due to invalid locale"_s);
         return;
     }

     m_numberingSystem = resolved.extensions[static_cast<unsigned>(RelevantExtensionKey::Nu)];
     CString dataLocaleWithExtensions = makeString(resolved.dataLocale, "-u-nu-", m_numberingSystem).utf8();

     m_style = intlOption<Style>(globalObject, options, vm.propertyNames->style, { { "long"_s, Style::Long }, { "short"_s, Style::Short }, { "narrow"_s, Style::Narrow } }, "style must be either \"long\", \"short\", or \"narrow\""_s, Style::Long);
     RETURN_IF_EXCEPTION(scope, void());
     UDateRelativeDateTimeFormatterStyle icuStyle = UDAT_STYLE_LONG;
     switch (m_style) {
     case Style::Long:
         icuStyle = UDAT_STYLE_LONG;
         break;
     case Style::Short:
         icuStyle = UDAT_STYLE_SHORT;
         break;
     case Style::Narrow:
         icuStyle = UDAT_STYLE_NARROW;
         break;
     }

     m_numeric = intlOption<bool>(globalObject, options, vm.propertyNames->numeric, { { "always"_s, true }, { "auto"_s, false } }, "numeric must be either \"always\" or \"auto\""_s, true);
     RETURN_IF_EXCEPTION(scope, void());

     UErrorCode status = U_ZERO_ERROR;
     m_numberFormat = std::unique_ptr<UNumberFormat, UNumberFormatDeleter>(unum_open(UNUM_DECIMAL, nullptr, 0, dataLocaleWithExtensions.data(), nullptr, &status));
     if (UNLIKELY(U_FAILURE(status))) {
         throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
         return;
     }

     // Align to IntlNumberFormat's default.
     unum_setAttribute(m_numberFormat.get(), UNUM_MIN_INTEGER_DIGITS, 1);
     unum_setAttribute(m_numberFormat.get(), UNUM_MIN_FRACTION_DIGITS, 0);
     unum_setAttribute(m_numberFormat.get(), UNUM_MAX_FRACTION_DIGITS, 3);
     unum_setAttribute(m_numberFormat.get(), UNUM_GROUPING_USED, true);

     // Grouping attributes have hidden -2 option which makes grouping rules locale-sensitive.
     // While this is supported so long, this is not explicitly exposed as APIs.
     // After ICU 68, it is now exposed as UNUM_MINIMUM_GROUPING_DIGITS_AUTO. Before ICU 68, we can directly use -2.
     // https://unicode-org.atlassian.net/browse/ICU-21109
     // https://github.com/unicode-org/icu/commit/e7bd5b1cefa47a043a9714e21eb9946dd54d593f
     //
     // These options are tested in test262/test/intl402/RelativeTimeFormat/prototype/format/pl-pl-style-long.js etc.
     // e.g. https://github.com/tc39/test262/commit/79c1818a6812a2a6c47e3e3c56ba9f2b3eaff4d5
     constexpr int32_t useLocaleDefault = -2;
     unum_setAttribute(m_numberFormat.get(), UNUM_GROUPING_SIZE, useLocaleDefault);
     unum_setAttribute(m_numberFormat.get(), UNUM_SECONDARY_GROUPING_SIZE, useLocaleDefault);
     unum_setAttribute(m_numberFormat.get(), UNUM_MINIMUM_GROUPING_DIGITS, useLocaleDefault);

     UNumberFormat* clonedNumberFormat = unum_clone(m_numberFormat.get(), &status);
     if (UNLIKELY(U_FAILURE(status))) {
         throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
         return;
     }

     m_relativeDateTimeFormatter = std::unique_ptr<URelativeDateTimeFormatter, URelativeDateTimeFormatterDeleter>(ureldatefmt_open(dataLocaleWithExtensions.data(), clonedNumberFormat, icuStyle, UDISPCTX_CAPITALIZATION_FOR_STANDALONE, &status));
     if (UNLIKELY(U_FAILURE(status))) {
         throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
         return;
     }
 }

 ASCIILiteral IntlRelativeTimeFormat::styleString(Style style)
 {
     switch (style) {
     case Style::Long:
         return "long"_s;
     case Style::Short:
         return "short"_s;
     case Style::Narrow:
         return "narrow"_s;
     }
     ASSERT_NOT_REACHED();
     return ASCIILiteral::null();
 }

 // https://tc39.es/ecma402/#sec-intl.relativetimeformat.prototype.resolvedoptions
 JSObject* IntlRelativeTimeFormat::resolvedOptions(JSGlobalObject* globalObject) const
 {
     VM& vm = globalObject->vm();
     JSObject* options = constructEmptyObject(globalObject);
     options->putDirect(vm, vm.propertyNames->locale, jsNontrivialString(vm, m_locale));
     options->putDirect(vm, vm.propertyNames->style, jsNontrivialString(vm, styleString(m_style)));
     options->putDirect(vm, vm.propertyNames->numeric, jsNontrivialString(vm, m_numeric ? "always"_s : "auto"_s));
     options->putDirect(vm, vm.propertyNames->numberingSystem, jsNontrivialString(vm, m_numberingSystem));
     return options;
 }

 static StringView singularUnit(StringView unit)
 {
     // Plurals are allowed, but thankfully they're all just a simple -s.
     return unit.endsWith("s") ? unit.left(unit.length() - 1) : unit;
 }

 // https://tc39.es/ecma402/#sec-singularrelativetimeunit
 static std::optional<URelativeDateTimeUnit> relativeTimeUnitType(StringView unit)
 {
     StringView singular = singularUnit(unit);

     if (singular == "second")
         return UDAT_REL_UNIT_SECOND;
     if (singular == "minute")
         return UDAT_REL_UNIT_MINUTE;
     if (singular == "hour")
         return UDAT_REL_UNIT_HOUR;
     if (singular == "day")
         return UDAT_REL_UNIT_DAY;
     if (singular == "week")
         return UDAT_REL_UNIT_WEEK;
     if (singular == "month")
         return UDAT_REL_UNIT_MONTH;
     if (singular == "quarter")
         return UDAT_REL_UNIT_QUARTER;
     if (singular == "year")
         return UDAT_REL_UNIT_YEAR;

     return std::nullopt;
 }

 String IntlRelativeTimeFormat::formatInternal(JSGlobalObject* globalObject, double value, StringView unit) const
 {
     ASSERT(m_relativeDateTimeFormatter);

     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     if (!std::isfinite(value)) {
         throwRangeError(globalObject, scope, "number argument must be finite"_s);
         return String();
     }

     auto unitType = relativeTimeUnitType(unit);
     if (!unitType) {
         throwRangeError(globalObject, scope, "unit argument is not a recognized unit type"_s);
         return String();
     }

     auto formatRelativeTime = m_numeric ? ureldatefmt_formatNumeric : ureldatefmt_format;

     Vector<UChar, 32> result;
     auto status = callBufferProducingFunction(formatRelativeTime, m_relativeDateTimeFormatter.get(), value, unitType.value(), result);
     if (UNLIKELY(U_FAILURE(status))) {
         throwTypeError(globalObject, scope, "failed to format relative time"_s);
         return String();
     }

     return String(result);
 }

 // https://tc39.es/ecma402/#sec-FormatRelativeTime
 JSValue IntlRelativeTimeFormat::format(JSGlobalObject* globalObject, double value, StringView unit) const
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     String result = formatInternal(globalObject, value, unit);
     RETURN_IF_EXCEPTION(scope, { });

     return jsString(vm, result);
 }

 // https://tc39.es/ecma402/#sec-FormatRelativeTimeToParts
 JSValue IntlRelativeTimeFormat::formatToParts(JSGlobalObject* globalObject, double value, StringView unit) const
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     String formattedRelativeTime = formatInternal(globalObject, value, unit);
     RETURN_IF_EXCEPTION(scope, { });

     UErrorCode status = U_ZERO_ERROR;
     auto iterator = std::unique_ptr<UFieldPositionIterator, UFieldPositionIteratorDeleter>(ufieldpositer_open(&status));
     ASSERT(U_SUCCESS(status));

     double absValue = std::abs(value);

     Vector<UChar, 32> buffer;
     status = callBufferProducingFunction(unum_formatDoubleForFields, m_numberFormat.get(), absValue, buffer, iterator.get());
     if (U_FAILURE(status))
         return throwTypeError(globalObject, scope, "failed to format relative time"_s);

     auto formattedNumber = String(buffer);

     JSArray* parts = JSArray::tryCreate(vm, globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous), 0);
     if (!parts)
         return throwOutOfMemoryError(globalObject, scope);

     JSString* literalString = jsNontrivialString(vm, "literal"_s);

     // We only have one input number, so our relative time will have at most one numeric substring,
     // but we need to list all of the numeric parts separately.
     size_t numberEnd = 0;
     size_t numberStart = formattedRelativeTime.find(formattedNumber);
     if (numberStart != notFound) {
         numberEnd = numberStart + buffer.size();

         // Add initial literal if there is one.
         if (numberStart) {
             JSObject* part = constructEmptyObject(globalObject);
             part->putDirect(vm, vm.propertyNames->type, literalString);
             part->putDirect(vm, vm.propertyNames->value, jsSubstring(vm, formattedRelativeTime, 0, numberStart));
             parts->push(globalObject, part);
             RETURN_IF_EXCEPTION(scope, { });
         }

         IntlFieldIterator fieldIterator(*iterator.get());
         IntlNumberFormat::formatToPartsInternal(globalObject, IntlNumberFormat::Style::Decimal, absValue, formattedNumber, fieldIterator, parts, jsString(vm, singularUnit(unit).toString()));
         RETURN_IF_EXCEPTION(scope, { });
     }

     // Add final literal if there is one.
     auto stringLength = formattedRelativeTime.length();
     if (numberEnd != stringLength) {
         JSObject* part = constructEmptyObject(globalObject);
         part->putDirect(vm, vm.propertyNames->type, literalString);
         part->putDirect(vm, vm.propertyNames->value, jsSubstring(vm, formattedRelativeTime, numberEnd, stringLength - numberEnd));
         parts->push(globalObject, part);
         RETURN_IF_EXCEPTION(scope, { });
     }

     return parts;
 }

 } // namespace JSC
	/*
	* Copyright (C) 2020 Sony Interactive Entertainment Inc.
	* Copyright (C) 2021 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "IntlRelativeTimeFormat.h"

	#include "IntlNumberFormatInlines.h"
	#include "IntlObjectInlines.h"
	#include "JSCInlines.h"
	#include "ObjectConstructor.h"
	#include <wtf/unicode/icu/ICUHelpers.h>

	namespace JSC {

	const ClassInfo IntlRelativeTimeFormat::s_info = { "Object", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(IntlRelativeTimeFormat) };

	namespace IntlRelativeTimeFormatInternal {
	}

	IntlRelativeTimeFormat* IntlRelativeTimeFormat::create(VM& vm, Structure* structure)
	{
	auto* format = new (NotNull, allocateCell<IntlRelativeTimeFormat>(vm.heap)) IntlRelativeTimeFormat(vm, structure);
	format->finishCreation(vm);
	return format;
	}

	Structure* IntlRelativeTimeFormat::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
	{
	return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
	}

	IntlRelativeTimeFormat::IntlRelativeTimeFormat(VM& vm, Structure* structure)
	: Base(vm, structure)
	{
	}

	void IntlRelativeTimeFormat::finishCreation(VM& vm)
	{
	Base::finishCreation(vm);
	ASSERT(inherits(vm, info()));
	}

	template<typename Visitor>
	void IntlRelativeTimeFormat::visitChildrenImpl(JSCell* cell, Visitor& visitor)
	{
	auto* thisObject = jsCast<IntlRelativeTimeFormat*>(cell);
	ASSERT_GC_OBJECT_INHERITS(thisObject, info());

	Base::visitChildren(thisObject, visitor);
	}

	DEFINE_VISIT_CHILDREN(IntlRelativeTimeFormat);

	Vector<String> IntlRelativeTimeFormat::localeData(const String& locale, RelevantExtensionKey key)
	{
	ASSERT_UNUSED(key, key == RelevantExtensionKey::Nu);
	return numberingSystemsForLocale(locale);
	}

	// https://tc39.es/ecma402/#sec-InitializeRelativeTimeFormat
	void IntlRelativeTimeFormat::initializeRelativeTimeFormat(JSGlobalObject* globalObject, JSValue locales, JSValue optionsValue)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	Vector<String> requestedLocales = canonicalizeLocaleList(globalObject, locales);
	RETURN_IF_EXCEPTION(scope, void());

	JSObject* options = intlCoerceOptionsToObject(globalObject, optionsValue);
	RETURN_IF_EXCEPTION(scope, void());

	ResolveLocaleOptions localeOptions;
	LocaleMatcher localeMatcher = intlOption<LocaleMatcher>(globalObject, options, vm.propertyNames->localeMatcher, { { "lookup"_s, LocaleMatcher::Lookup }, { "best fit"_s, LocaleMatcher::BestFit } }, "localeMatcher must be either \"lookup\" or \"best fit\""_s, LocaleMatcher::BestFit);
	RETURN_IF_EXCEPTION(scope, void());

	String numberingSystem = intlStringOption(globalObject, options, vm.propertyNames->numberingSystem, { }, nullptr, nullptr);
	RETURN_IF_EXCEPTION(scope, void());
	if (!numberingSystem.isNull()) {
	if (!isUnicodeLocaleIdentifierType(numberingSystem)) {
	throwRangeError(globalObject, scope, "numberingSystem is not a well-formed numbering system value"_s);
	return;
	}
	localeOptions[static_cast<unsigned>(RelevantExtensionKey::Nu)] = numberingSystem;
	}

	const auto& availableLocales = intlRelativeTimeFormatAvailableLocales();
	auto resolved = resolveLocale(globalObject, availableLocales, requestedLocales, localeMatcher, localeOptions, { RelevantExtensionKey::Nu }, localeData);
	m_locale = resolved.locale;
	if (m_locale.isEmpty()) {
	throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat due to invalid locale"_s);
	return;
	}

	m_numberingSystem = resolved.extensions[static_cast<unsigned>(RelevantExtensionKey::Nu)];
	CString dataLocaleWithExtensions = makeString(resolved.dataLocale, "-u-nu-", m_numberingSystem).utf8();

	m_style = intlOption<Style>(globalObject, options, vm.propertyNames->style, { { "long"_s, Style::Long }, { "short"_s, Style::Short }, { "narrow"_s, Style::Narrow } }, "style must be either \"long\", \"short\", or \"narrow\""_s, Style::Long);
	RETURN_IF_EXCEPTION(scope, void());
	UDateRelativeDateTimeFormatterStyle icuStyle = UDAT_STYLE_LONG;
	switch (m_style) {
	case Style::Long:
	icuStyle = UDAT_STYLE_LONG;
	break;
	case Style::Short:
	icuStyle = UDAT_STYLE_SHORT;
	break;
	case Style::Narrow:
	icuStyle = UDAT_STYLE_NARROW;
	break;
	}

	m_numeric = intlOption<bool>(globalObject, options, vm.propertyNames->numeric, { { "always"_s, true }, { "auto"_s, false } }, "numeric must be either \"always\" or \"auto\""_s, true);
	RETURN_IF_EXCEPTION(scope, void());

	UErrorCode status = U_ZERO_ERROR;
	m_numberFormat = std::unique_ptr<UNumberFormat, UNumberFormatDeleter>(unum_open(UNUM_DECIMAL, nullptr, 0, dataLocaleWithExtensions.data(), nullptr, &status));
	if (UNLIKELY(U_FAILURE(status))) {
	throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
	return;
	}

	// Align to IntlNumberFormat's default.
	unum_setAttribute(m_numberFormat.get(), UNUM_MIN_INTEGER_DIGITS, 1);
	unum_setAttribute(m_numberFormat.get(), UNUM_MIN_FRACTION_DIGITS, 0);
	unum_setAttribute(m_numberFormat.get(), UNUM_MAX_FRACTION_DIGITS, 3);
	unum_setAttribute(m_numberFormat.get(), UNUM_GROUPING_USED, true);

	// Grouping attributes have hidden -2 option which makes grouping rules locale-sensitive.
	// While this is supported so long, this is not explicitly exposed as APIs.
	// After ICU 68, it is now exposed as UNUM_MINIMUM_GROUPING_DIGITS_AUTO. Before ICU 68, we can directly use -2.
	// https://unicode-org.atlassian.net/browse/ICU-21109
	// https://github.com/unicode-org/icu/commit/e7bd5b1cefa47a043a9714e21eb9946dd54d593f
	//
	// These options are tested in test262/test/intl402/RelativeTimeFormat/prototype/format/pl-pl-style-long.js etc.
	// e.g. https://github.com/tc39/test262/commit/79c1818a6812a2a6c47e3e3c56ba9f2b3eaff4d5
	constexpr int32_t useLocaleDefault = -2;
	unum_setAttribute(m_numberFormat.get(), UNUM_GROUPING_SIZE, useLocaleDefault);
	unum_setAttribute(m_numberFormat.get(), UNUM_SECONDARY_GROUPING_SIZE, useLocaleDefault);
	unum_setAttribute(m_numberFormat.get(), UNUM_MINIMUM_GROUPING_DIGITS, useLocaleDefault);

	UNumberFormat* clonedNumberFormat = unum_clone(m_numberFormat.get(), &status);
	if (UNLIKELY(U_FAILURE(status))) {
	throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
	return;
	}

	m_relativeDateTimeFormatter = std::unique_ptr<URelativeDateTimeFormatter, URelativeDateTimeFormatterDeleter>(ureldatefmt_open(dataLocaleWithExtensions.data(), clonedNumberFormat, icuStyle, UDISPCTX_CAPITALIZATION_FOR_STANDALONE, &status));
	if (UNLIKELY(U_FAILURE(status))) {
	throwTypeError(globalObject, scope, "failed to initialize RelativeTimeFormat"_s);
	return;
	}
	}

	ASCIILiteral IntlRelativeTimeFormat::styleString(Style style)
	{
	switch (style) {
	case Style::Long:
	return "long"_s;
	case Style::Short:
	return "short"_s;
	case Style::Narrow:
	return "narrow"_s;
	}
	ASSERT_NOT_REACHED();
	return ASCIILiteral::null();
	}

	// https://tc39.es/ecma402/#sec-intl.relativetimeformat.prototype.resolvedoptions
	JSObject* IntlRelativeTimeFormat::resolvedOptions(JSGlobalObject* globalObject) const
	{
	VM& vm = globalObject->vm();
	JSObject* options = constructEmptyObject(globalObject);
	options->putDirect(vm, vm.propertyNames->locale, jsNontrivialString(vm, m_locale));
	options->putDirect(vm, vm.propertyNames->style, jsNontrivialString(vm, styleString(m_style)));
	options->putDirect(vm, vm.propertyNames->numeric, jsNontrivialString(vm, m_numeric ? "always"_s : "auto"_s));
	options->putDirect(vm, vm.propertyNames->numberingSystem, jsNontrivialString(vm, m_numberingSystem));
	return options;
	}

	static StringView singularUnit(StringView unit)
	{
	// Plurals are allowed, but thankfully they're all just a simple -s.
	return unit.endsWith("s") ? unit.left(unit.length() - 1) : unit;
	}

	// https://tc39.es/ecma402/#sec-singularrelativetimeunit
	static std::optional<URelativeDateTimeUnit> relativeTimeUnitType(StringView unit)
	{
	StringView singular = singularUnit(unit);

	if (singular == "second")
	return UDAT_REL_UNIT_SECOND;
	if (singular == "minute")
	return UDAT_REL_UNIT_MINUTE;
	if (singular == "hour")
	return UDAT_REL_UNIT_HOUR;
	if (singular == "day")
	return UDAT_REL_UNIT_DAY;
	if (singular == "week")
	return UDAT_REL_UNIT_WEEK;
	if (singular == "month")
	return UDAT_REL_UNIT_MONTH;
	if (singular == "quarter")
	return UDAT_REL_UNIT_QUARTER;
	if (singular == "year")
	return UDAT_REL_UNIT_YEAR;

	return std::nullopt;
	}

	String IntlRelativeTimeFormat::formatInternal(JSGlobalObject* globalObject, double value, StringView unit) const
	{
	ASSERT(m_relativeDateTimeFormatter);

	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	if (!std::isfinite(value)) {
	throwRangeError(globalObject, scope, "number argument must be finite"_s);
	return String();
	}

	auto unitType = relativeTimeUnitType(unit);
	if (!unitType) {
	throwRangeError(globalObject, scope, "unit argument is not a recognized unit type"_s);
	return String();
	}

	auto formatRelativeTime = m_numeric ? ureldatefmt_formatNumeric : ureldatefmt_format;

	Vector<UChar, 32> result;
	auto status = callBufferProducingFunction(formatRelativeTime, m_relativeDateTimeFormatter.get(), value, unitType.value(), result);
	if (UNLIKELY(U_FAILURE(status))) {
	throwTypeError(globalObject, scope, "failed to format relative time"_s);
	return String();
	}

	return String(result);
	}

	// https://tc39.es/ecma402/#sec-FormatRelativeTime
	JSValue IntlRelativeTimeFormat::format(JSGlobalObject* globalObject, double value, StringView unit) const
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	String result = formatInternal(globalObject, value, unit);
	RETURN_IF_EXCEPTION(scope, { });

	return jsString(vm, result);
	}

	// https://tc39.es/ecma402/#sec-FormatRelativeTimeToParts
	JSValue IntlRelativeTimeFormat::formatToParts(JSGlobalObject* globalObject, double value, StringView unit) const
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	String formattedRelativeTime = formatInternal(globalObject, value, unit);
	RETURN_IF_EXCEPTION(scope, { });

	UErrorCode status = U_ZERO_ERROR;
	auto iterator = std::unique_ptr<UFieldPositionIterator, UFieldPositionIteratorDeleter>(ufieldpositer_open(&status));
	ASSERT(U_SUCCESS(status));

	double absValue = std::abs(value);

	Vector<UChar, 32> buffer;
	status = callBufferProducingFunction(unum_formatDoubleForFields, m_numberFormat.get(), absValue, buffer, iterator.get());
	if (U_FAILURE(status))
	return throwTypeError(globalObject, scope, "failed to format relative time"_s);

	auto formattedNumber = String(buffer);

	JSArray* parts = JSArray::tryCreate(vm, globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous), 0);
	if (!parts)
	return throwOutOfMemoryError(globalObject, scope);

	JSString* literalString = jsNontrivialString(vm, "literal"_s);

	// We only have one input number, so our relative time will have at most one numeric substring,
	// but we need to list all of the numeric parts separately.
	size_t numberEnd = 0;
	size_t numberStart = formattedRelativeTime.find(formattedNumber);
	if (numberStart != notFound) {
	numberEnd = numberStart + buffer.size();

	// Add initial literal if there is one.
	if (numberStart) {
	JSObject* part = constructEmptyObject(globalObject);
	part->putDirect(vm, vm.propertyNames->type, literalString);
	part->putDirect(vm, vm.propertyNames->value, jsSubstring(vm, formattedRelativeTime, 0, numberStart));
	parts->push(globalObject, part);
	RETURN_IF_EXCEPTION(scope, { });
	}

	IntlFieldIterator fieldIterator(*iterator.get());
	IntlNumberFormat::formatToPartsInternal(globalObject, IntlNumberFormat::Style::Decimal, absValue, formattedNumber, fieldIterator, parts, jsString(vm, singularUnit(unit).toString()));
	RETURN_IF_EXCEPTION(scope, { });
	}

	// Add final literal if there is one.
	auto stringLength = formattedRelativeTime.length();
	if (numberEnd != stringLength) {
	JSObject* part = constructEmptyObject(globalObject);
	part->putDirect(vm, vm.propertyNames->type, literalString);
	part->putDirect(vm, vm.propertyNames->value, jsSubstring(vm, formattedRelativeTime, numberEnd, stringLength - numberEnd));
	parts->push(globalObject, part);
	RETURN_IF_EXCEPTION(scope, { });
	}

	return parts;
	}

	} // namespace JSC