LibJS: Implement Intl.PluralRules.prototype.selectRange

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -409,6 +409,7 @@ namespace JS {
     P(secondsDisplay)                        \
     P(segment)                               \
     P(select)                                \
+    P(selectRange)                           \
     P(sensitivity)                           \
     P(set)                                   \
     P(setBigInt64)                           \

Userland/Libraries/LibJS/Runtime/ErrorTypes.h

@@ -43,8 +43,10 @@
     M(IntlInvalidLanguageTag, "{} is not a structurally valid language tag")                                                            \
     M(IntlInvalidTime, "Time value must be between -8.64E15 and 8.64E15")                                                               \
     M(IntlInvalidUnit, "Unit {} is not a valid time unit")                                                                              \
+    M(IntlStartRangeAfterEndRange, "Range start {} is greater than range end {}")                                                       \
     M(IntlStartTimeAfterEndTime, "Start time {} is after end time {}")                                                                  \
     M(IntlMinimumExceedsMaximum, "Minimum value {} is larger than maximum value {}")                                                    \
+    M(IntlNumberIsNaN, "{} must not be NaN")                                                                                            \
     M(IntlNumberIsNaNOrInfinity, "Number must not be NaN or Infinity")                                                                  \
     M(IntlNumberIsNaNOrOutOfRange, "Value {} is NaN or is not between {} and {}")                                                       \
     M(IntlOptionUndefined, "Option {} must be defined when option {} is {}")                                                            \

Userland/Libraries/LibJS/Runtime/Intl/PluralRules.cpp

@@ -130,4 +130,46 @@ Unicode::PluralCategory resolve_plural(GlobalObject& global_object, NumberFormat
     return plural_rule_select(locale, type, number, move(operands));
 }
 
+// 1.1.5 PluralRuleSelectRange ( locale, type, xp, yp ), https://tc39.es/proposal-intl-numberformat-v3/out/pluralrules/proposed.html#sec-pluralruleselectrange
+Unicode::PluralCategory plural_rule_select_range(StringView locale, Unicode::PluralForm, Unicode::PluralCategory start, Unicode::PluralCategory end)
+{
+    return Unicode::determine_plural_range(locale, start, end);
+}
+
+// 1.1.6 ResolvePluralRange ( pluralRules, x, y ), https://tc39.es/proposal-intl-numberformat-v3/out/pluralrules/proposed.html#sec-resolvepluralrange
+ThrowCompletionOr<Unicode::PluralCategory> resolve_plural_range(GlobalObject& global_object, PluralRules const& plural_rules, Value start, Value end)
+{
+    auto& vm = global_object.vm();
+
+    // 1. Assert: Type(pluralRules) is Object.
+    // 2. Assert: pluralRules has an [[InitializedPluralRules]] internal slot.
+    // 3. Assert: Type(x) is Number.
+    // 4. Assert: Type(y) is Number.
+
+    // 5. If x is NaN or y is NaN, throw a RangeError exception.
+    if (start.is_nan())
+        return vm.throw_completion<RangeError>(global_object, ErrorType::IntlNumberIsNaN, "start"sv);
+    if (end.is_nan())
+        return vm.throw_completion<RangeError>(global_object, ErrorType::IntlNumberIsNaN, "end"sv);
+
+    // 6. If x > y, throw a RangeError exception.
+    if (start.as_double() > end.as_double())
+        return vm.throw_completion<RangeError>(global_object, ErrorType::IntlStartRangeAfterEndRange, start, end);
+
+    // 7. Let xp be ! ResolvePlural(pluralRules, x).
+    auto start_plurality = resolve_plural(global_object, plural_rules, start);
+
+    // 8. Let yp be ! ResolvePlural(pluralRules, y).
+    auto end_plurality = resolve_plural(global_object, plural_rules, end);
+
+    // 9. Let locale be pluralRules.[[Locale]].
+    auto const& locale = plural_rules.locale();
+
+    // 10. Let type be pluralRules.[[Type]].
+    auto type = plural_rules.type();
+
+    // 11. Return ! PluralRuleSelectRange(locale, type, xp, yp).
+    return plural_rule_select_range(locale, type, start_plurality, end_plurality);
+}
+
 }

Userland/Libraries/LibJS/Runtime/Intl/PluralRules.h

@@ -8,6 +8,7 @@
 
 #include <AK/String.h>
 #include <AK/StringView.h>
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/Intl/NumberFormat.h>
 #include <LibJS/Runtime/Object.h>
 #include <LibUnicode/PluralRules.h>
@@ -33,5 +34,7 @@ Unicode::PluralOperands get_operands(String const& string);
 Unicode::PluralCategory plural_rule_select(StringView locale, Unicode::PluralForm type, Value number, Unicode::PluralOperands operands);
 Unicode::PluralCategory resolve_plural(GlobalObject& global_object, PluralRules const& plural_rules, Value number);
 Unicode::PluralCategory resolve_plural(GlobalObject& global_object, NumberFormatBase const& number_format, Unicode::PluralForm type, Value number);
+Unicode::PluralCategory plural_rule_select_range(StringView locale, Unicode::PluralForm, Unicode::PluralCategory start, Unicode::PluralCategory end);
+ThrowCompletionOr<Unicode::PluralCategory> resolve_plural_range(GlobalObject& global_object, PluralRules const& plural_rules, Value start, Value end);
 
 }

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesPrototype.cpp

@@ -29,6 +29,7 @@ void PluralRulesPrototype::initialize(GlobalObject& global_object)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(vm.names.select, select, 1, attr);
+    define_native_function(vm.names.selectRange, select_range, 2, attr);
     define_native_function(vm.names.resolvedOptions, resolved_options, 0, attr);
 }
 
@@ -47,6 +48,33 @@ JS_DEFINE_NATIVE_FUNCTION(PluralRulesPrototype::select)
     return js_string(vm, Unicode::plural_category_to_string(plurality));
 }
 
+// 1.4.4 Intl.PluralRules.prototype.selectRange ( start, end ), https://tc39.es/proposal-intl-numberformat-v3/out/pluralrules/proposed.html#sec-intl.pluralrules.prototype.selectrange
+JS_DEFINE_NATIVE_FUNCTION(PluralRulesPrototype::select_range)
+{
+    auto start = vm.argument(0);
+    auto end = vm.argument(1);
+
+    // 1. Let pr be the this value.
+    // 2. Perform ? RequireInternalSlot(pr, [[InitializedPluralRules]]).
+    auto* plural_rules = TRY(typed_this_object(global_object));
+
+    // 3. If start is undefined or end is undefined, throw a TypeError exception.
+    if (start.is_undefined())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::IsUndefined, "start"sv);
+    if (end.is_undefined())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::IsUndefined, "end"sv);
+
+    // 4. Let x be ? ToNumber(start).
+    auto x = TRY(start.to_number(global_object));
+
+    // 5. Let y be ? ToNumber(end).
+    auto y = TRY(end.to_number(global_object));
+
+    // 6. Return ? ResolvePluralRange(pr, x, y).
+    auto plurality = TRY(resolve_plural_range(global_object, *plural_rules, x, y));
+    return js_string(vm, Unicode::plural_category_to_string(plurality));
+}
+
 // 16.3.4 Intl.PluralRules.prototype.resolvedOptions ( ), https://tc39.es/ecma402/#sec-intl.pluralrules.prototype.resolvedoptions
 JS_DEFINE_NATIVE_FUNCTION(PluralRulesPrototype::resolved_options)
 {

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesPrototype.h

@@ -21,6 +21,7 @@ public:
 
 private:
     JS_DECLARE_NATIVE_FUNCTION(select);
+    JS_DECLARE_NATIVE_FUNCTION(select_range);
     JS_DECLARE_NATIVE_FUNCTION(resolved_options);
 };
 

Userland/Libraries/LibJS/Tests/builtins/Intl/PluralRules/PluralRules.prototype.selectRange.js

@@ -0,0 +1,73 @@
+describe("errors", () => {
+    test("called on non-PluralRules object", () => {
+        expect(() => {
+            Intl.PluralRules.prototype.selectRange();
+        }).toThrowWithMessage(TypeError, "Not an object of type Intl.PluralRules");
+    });
+
+    test("called without enough values", () => {
+        expect(() => {
+            new Intl.PluralRules().selectRange();
+        }).toThrowWithMessage(TypeError, "start is undefined");
+
+        expect(() => {
+            new Intl.PluralRules().selectRange(1);
+        }).toThrowWithMessage(TypeError, "end is undefined");
+    });
+
+    test("called with values that cannot be converted to numbers", () => {
+        expect(() => {
+            new Intl.PluralRules().selectRange(Symbol.hasInstance, 1);
+        }).toThrowWithMessage(TypeError, "Cannot convert symbol to number");
+
+        expect(() => {
+            new Intl.PluralRules().selectRange(1, Symbol.hasInstance);
+        }).toThrowWithMessage(TypeError, "Cannot convert symbol to number");
+    });
+
+    test("called with invalid numbers", () => {
+        expect(() => {
+            new Intl.PluralRules().selectRange(NaN, 1);
+        }).toThrowWithMessage(RangeError, "start must not be NaN");
+
+        expect(() => {
+            new Intl.PluralRules().selectRange(1, NaN);
+        }).toThrowWithMessage(RangeError, "end must not be NaN");
+
+        expect(() => {
+            new Intl.PluralRules().selectRange(1, 0);
+        }).toThrowWithMessage(RangeError, "Range start 1 is greater than range end 0");
+    });
+});
+
+describe("correct behavior", () => {
+    test("basic functionality", () => {
+        const en = new Intl.PluralRules("en");
+        expect(en.selectRange(1, 2)).toBe("other"); // one + other = other
+        expect(en.selectRange(0, 1)).toBe("other"); // other + one = other
+        expect(en.selectRange(2, 3)).toBe("other"); // other + other = other
+
+        const pl = new Intl.PluralRules("pl");
+        expect(pl.selectRange(1, 2)).toBe("few"); // one + few = few
+        expect(pl.selectRange(1, 5)).toBe("many"); // one + many = many
+        expect(pl.selectRange(1, 3.14)).toBe("other"); // one + other = other
+        expect(pl.selectRange(2, 2)).toBe("few"); // few + few = few
+        expect(pl.selectRange(2, 5)).toBe("many"); // few + many = many
+        expect(pl.selectRange(2, 3.14)).toBe("other"); // few + other = other
+        expect(pl.selectRange(0, 1)).toBe("one"); // many + one = one
+        expect(pl.selectRange(0, 2)).toBe("few"); // many + few = few
+        expect(pl.selectRange(0, 5)).toBe("many"); // many + many = many
+        expect(pl.selectRange(0, 3.14)).toBe("other"); // many + other = other
+        expect(pl.selectRange(0.14, 1)).toBe("one"); // other + one = one
+        expect(pl.selectRange(0.14, 2)).toBe("few"); // other + few = few
+        expect(pl.selectRange(0.14, 5)).toBe("many"); // other + many = many
+        expect(pl.selectRange(0.14, 3.14)).toBe("other"); // other + other = other
+    });
+
+    test("default to end of range", () => {
+        // "so" specifies "one" to be the integer 1, but does not specify any ranges.
+        const so = new Intl.PluralRules("so");
+        expect(so.selectRange(0, 1)).toBe("one");
+        expect(so.selectRange(1, 2)).toBe("other");
+    });
+});