fix(core): handle pluralize functions that expect a number (#36901)

Previously we were passing a string form of the value to pluralize
to the `getLocalePluralCase()` function that is extracted from the
locale data. But some locales have functions that rely upon this
value being a number not a string.

Now we convert the value to a number before passing it to the
locale data function.

Fixes #36888

PR Close #36901

packages/core/src/i18n/localization.ts

@@ -8,26 +8,15 @@
 
 import {getLocalePluralCase} from './locale_data_api';
 
+const pluralMapping = ['zero', 'one', 'two', 'few', 'many'];
+
 /**
  * Returns the plural case based on the locale
  */
-export function getPluralCase(value: any, locale: string): string {
-  const plural = getLocalePluralCase(locale)(value);
-
-  switch (plural) {
-    case 0:
-      return 'zero';
-    case 1:
-      return 'one';
-    case 2:
-      return 'two';
-    case 3:
-      return 'few';
-    case 4:
-      return 'many';
-    default:
-      return 'other';
-  }
+export function getPluralCase(value: string, locale: string): string {
+  const plural = getLocalePluralCase(locale)(parseInt(value, 10));
+  const result = pluralMapping[plural];
+  return (result !== undefined) ? result : 'other';
 }
 
 /**

packages/core/test/acceptance/i18n_spec.ts

@@ -10,6 +10,7 @@
 import '@angular/localize/init';
 
 import {CommonModule, registerLocaleData} from '@angular/common';
+import localeEs from '@angular/common/locales/es';
 import localeRo from '@angular/common/locales/ro';
 import {computeMsgId} from '@angular/compiler';
 import {Component, ContentChild, ContentChildren, Directive, ElementRef, HostBinding, Input, LOCALE_ID, NO_ERRORS_SCHEMA, Pipe, PipeTransform, QueryList, TemplateRef, Type, ViewChild, ViewContainerRef} from '@angular/core';
@@ -770,7 +771,20 @@ onlyInIvy('Ivy i18n logic').describe('runtime i18n', () => {
       expect(fixture.nativeElement.innerHTML).toEqual(`<div>autre - 4<!--ICU 5--></div>`);
     });
 
-    it('should return the correct plural form for ICU expressions when using a specific locale', () => {
+    it('should return the correct plural form for ICU expressions when using "ro" locale', () => {
+      // The "ro" locale has a complex plural function that can handle muliple options
+      // (and string inputs)
+      //
+      // function plural(n: number): number {
+      //   let i = Math.floor(Math.abs(n)), v = n.toString().replace(/^[^.]*\.?/, '').length;
+      //   if (i === 1 && v === 0) return 1;
+      //   if (!(v === 0) || n === 0 ||
+      //       !(n === 1) && n % 100 === Math.floor(n % 100) && n % 100 >= 1 && n % 100 <= 19)
+      //     return 3;
+      //   return 5;
+      // }
+      //
+      // Compare this to the "es" locale in the next test
       loadTranslations({
         [computeMsgId(
             '{VAR_PLURAL, plural, =0 {no email} =one {one email} =few {a few emails} =other {lots of emails}}')]:
@@ -814,6 +828,57 @@ onlyInIvy('Ivy i18n logic').describe('runtime i18n', () => {
       expect(fixture.nativeElement.innerHTML).toEqual('no email<!--ICU 2-->');
     });
 
+    it(`should return the correct plural form for ICU expressions when using "es" locale`, () => {
+      // The "es" locale has a simple plural function that can only handle a few options
+      // (and not string inputs)
+      //
+      // function plural(n: number): number {
+      //   if (n === 1) return 1;
+      //   return 5;
+      // }
+      //
+      // Compare this to the "ro" locale in the previous test
+      const icuMessage = '{VAR_PLURAL, plural, =0 {no email} =one ' +
+          '{one email} =few {a few emails} =other {lots of emails}}';
+      loadTranslations({[computeMsgId(icuMessage)]: icuMessage});
+      registerLocaleData(localeEs);
+      TestBed.configureTestingModule({providers: [{provide: LOCALE_ID, useValue: 'es'}]});
+      // We could also use `TestBed.overrideProvider(LOCALE_ID, {useValue: 'es'});`
+      const fixture = initWithTemplate(AppComp, `
+          {count, plural,
+            =0 {no email}
+            =one {one email}
+            =few {a few emails}
+            =other {lots of emails}
+          }`);
+
+      expect(fixture.nativeElement.innerHTML).toEqual('no email<!--ICU 2-->');
+
+      // Change detection cycle, no model changes
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('no email<!--ICU 2-->');
+
+      fixture.componentInstance.count = 3;
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('lots of emails<!--ICU 2-->');
+
+      fixture.componentInstance.count = 1;
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('one email<!--ICU 2-->');
+
+      fixture.componentInstance.count = 10;
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('lots of emails<!--ICU 2-->');
+
+      fixture.componentInstance.count = 20;
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('lots of emails<!--ICU 2-->');
+
+      fixture.componentInstance.count = 0;
+      fixture.detectChanges();
+      expect(fixture.nativeElement.innerHTML).toEqual('no email<!--ICU 2-->');
+    });
+
     it('projection', () => {
       loadTranslations({
         [computeMsgId('{VAR_PLURAL, plural, =1 {one} other {at least {INTERPOLATION} .}}')]: