Cover all plural forms in NumberParser (#5134)

* Cover all plural forms in NumberParser

Author: jbovenschen

packages/@internationalized/number/src/NumberParser.ts

@@ -191,11 +191,18 @@ class NumberParserImpl {
 
 const nonLiteralParts = new Set(['decimal', 'fraction', 'integer', 'minusSign', 'plusSign', 'group']);
 
+// This list is derived from https://www.unicode.org/cldr/charts/43/supplemental/language_plural_rules.html#comparison and includes
+// all unique numbers which we need to check in order to determine all the plural forms for a given locale.
+// See: https://github.com/adobe/react-spectrum/pull/5134/files#r1337037855 for used script
+const pluralNumbers = [
+  0, 4, 2, 1, 11, 20, 3, 7, 100, 21, 0.1, 1.1
+];
+
 function getSymbols(formatter: Intl.NumberFormat, intlOptions: Intl.ResolvedNumberFormatOptions, originalOptions: Intl.NumberFormatOptions): Symbols {
   // Note: some locale's don't add a group symbol until there is a ten thousands place
   let allParts = formatter.formatToParts(-10000.111);
   let posAllParts = formatter.formatToParts(10000.111);
-  let singularParts = formatter.formatToParts(1);
+  let pluralParts = pluralNumbers.map(n => formatter.formatToParts(n));
 
   let minusSign = allParts.find(p => p.type === 'minusSign')?.value ?? '-';
   let plusSign = posAllParts.find(p => p.type === 'plusSign')?.value;
@@ -212,9 +219,10 @@ function getSymbols(formatter: Intl.NumberFormat, intlOptions: Intl.ResolvedNumb
 
   // this set is also for a regex, it's all literals that might be in the string we want to eventually parse that
   // don't contribute to the numerical value
-  let pluralLiterals = allParts.filter(p => !nonLiteralParts.has(p.type)).map(p => escapeRegex(p.value));
-  let singularLiterals = singularParts.filter(p => !nonLiteralParts.has(p.type)).map(p => escapeRegex(p.value));
-  let sortedLiterals = [...new Set([...singularLiterals, ...pluralLiterals])].sort((a, b) => b.length - a.length);
+  let allPartsLiterals = allParts.filter(p => !nonLiteralParts.has(p.type)).map(p => escapeRegex(p.value));
+  let pluralPartsLiterals = pluralParts.flatMap(p => p.filter(p => !nonLiteralParts.has(p.type)).map(p => escapeRegex(p.value)));
+  let sortedLiterals = [...new Set([...allPartsLiterals, ...pluralPartsLiterals])].sort((a, b) => b.length - a.length);
+
   let literals = sortedLiterals.length === 0 ? 
       new RegExp('[\\p{White_Space}]', 'gu') :
       new RegExp(`${sortedLiterals.join('|')}|[\\p{White_Space}]`, 'gu');

packages/@internationalized/number/test/NumberParser.test.js

@@ -129,6 +129,24 @@ describe('NumberParser', function () {
       it('should return NaN for partial units', function () {
         expect(new NumberParser('en-US', {style: 'unit', unit: 'inch'}).parse('23.5 i')).toBe(NaN);
       });
+
+      it('should support plural forms', function () {
+        expect(new NumberParser('en-US', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('0 years')).toBe(0);
+        expect(new NumberParser('en-US', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1 year')).toBe(1);
+        expect(new NumberParser('en-US', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('2 years')).toBe(2);
+        expect(new NumberParser('en-US', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1.1 years')).toBe(1.1);
+
+        expect(new NumberParser('pl-PL', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('0 rok')).toBe(0);
+        expect(new NumberParser('pl-PL', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1 lat')).toBe(1);
+        expect(new NumberParser('pl-PL', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('2 lata')).toBe(2);
+        expect(new NumberParser('pl-PL', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('37 lata')).toBe(37);
+        expect(new NumberParser('pl-PL', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1.1 roku')).toBe(1.1);
+
+        expect(new NumberParser('fr-FR', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1 an')).toBe(1);
+        expect(new NumberParser('fr-FR', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('8 ans')).toBe(8);
+        expect(new NumberParser('fr-FR', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('1,3 an')).toBe(1.3);
+        expect(new NumberParser('fr-FR', {style: 'unit', unit: 'year', unitDisplay: 'long'}).parse('2,4 ans')).toBe(2.4);
+      });
     });
 
     describe('percents', function () {