From a74eb22871f366aebe2211bbe844d6c85fb925a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Viktor=20Sz=C3=A9pe?= <viktor@szepe.net>
Date: Tue, 7 Apr 2026 12:23:40 +0000
Subject: [PATCH] Fix implementation of trans_choice and improve README

---
 CHANGELOG.md         |  5 +++
 README.md            | 67 +++++++++++++++++----------------
 resources/js/I18n.js | 84 +++++++++++++++++++++++++++++++-----------
 tests/I18n.test.mjs  | 88 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 191 insertions(+), 53 deletions(-)
 create mode 100644 tests/I18n.test.mjs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a51d617..ebef2bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+# Unreleased
+### Fixed
+- Make the JavaScript `trans_choice()` implementation match Laravel's selector behavior
+- Fix JavaScript `trans_choice()` handling for literal strings and explicit pluralization selectors
+
 # v1.2.0 (2022-02-11)
 ### Added
 - Laravel 9 compatibility [#33](https://github.com/conedevelopment/i18n/pull/33)
diff --git a/README.md b/README.md
index 10abe3b..e50c568 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,15 @@
 # I18n
 
-Push your Laravel translations to the front-end and use them easily with JavaScript.
+Push your Laravel translations to the front end and use them easily with JavaScript.
 
-A nice tool for SPAs and front-end heavy applications.
+A useful tool for SPAs and front-end-heavy applications.
 
-If you have any question how the package works, we suggest to read this post:
+If you have any questions about how the package works, we suggest reading this post:
 [Using Laravel’s Localization in JS](https://pineco.de/using-laravels-localization-js/).
 
 ## Getting started
 
-You can install the package with composer, running the `composer require conedevelopment/i18n` command.
+Install the package with Composer by running `composer require conedevelopment/i18n`.
 
 ## Translations in view files
 
@@ -34,12 +34,12 @@ You may override the default key for the translations. You can do that by passin
 
 ## Publishing and using the JavaScript library
 
-Use the `php artisan vendor:publish` command and choose the `Pine\I18n\I18nServiceProvider` provider.
-After publishing you can find your fresh copy in the `resources/js/vendor` folder.
+Run `php artisan vendor:publish` and choose the `Pine\I18n\I18nServiceProvider` provider.
+After publishing, you can find the generated file in the `resources/js/vendor` directory.
 
 ### Using the I18n.js
 
-Then you can import the `I18n` class and assign it to the `window` object.
+You can then import the `I18n` class and assign it to the `window` object.
 
 ```js
 import I18n from './vendor/I18n';
@@ -48,28 +48,31 @@ window.I18n = I18n;
 
 ### Initializing a translation instance
 
-From this point you can initialize the translation service anywhere from your application.
+You can initialize the translation service anywhere in your application.
 
 ```js
 let translator = new I18n;
 ```
 
 By default, it uses the `translations` key in the `window` object.
-If you want to use the custom one you set in the blade directive, pass the same key to the constructor.
+If you want to use the custom key you set in the Blade directive, pass the same key to the constructor.
 
 ```js
 let translator = new I18n('myTranslations');
 ```
 
+`trans_choice()` falls back to the first form when the count is `1` and to the second form otherwise,
+unless an explicit selector like `{0}` or `[2,9]` matches first.
+
 ### Using it as a Vue service
 
-If you want to use it from Vue templates directly you can extend Vue with this easily.
+If you want to use it directly in Vue templates, you can extend Vue like this:
 
 ```js
 Vue.prototype.$I18n = new I18n;
 ```
 
-You can call it from your template or the script part of your component like below:
+You can call it from your template or from the script section of your component:
 
 ```html
 <template>
@@ -87,11 +90,11 @@ computed: {
 
 ### Methods
 
-The package comes with two methods on JS side. The `trans()` and the `trans_choice()`.
+The package provides two JavaScript methods: `trans()` and `trans_choice()`.
 
 #### `trans()`
 
-The `trans` method accepts the key of the translation and the attributes what we want to replace, but it's optional.
+The `trans` method accepts the translation key and an optional object of replacement values.
 
 ```js
 translator.trans('auth.failed');
@@ -105,8 +108,8 @@ translator.trans('auth.throttle', { seconds: 60 });
 
 #### `trans_choice()`
 
-The `trans_choice` method determines if the translation should be pluralized or nor by the given cout.
-Also, it accepts the attributes we want to replace.
+The `trans_choice` method selects the correct plural form for the given count.
+It also accepts an object of replacement values.
 
 Let's say we have the following translation line:
 
@@ -128,8 +131,8 @@ translator.trans_choice('auth.attempts', 4, { attempts: 'less than five' });
 // You still have less than five attempts left.
 ```
 
-Like in Laravel, you have the ability to set ranges for the pluralization.
-Also, you can replace placeholders like before.
+As in Laravel, you can define explicit pluralization ranges.
+You can also replace placeholders just like in `trans()`.
 
 ```php
 [
@@ -154,8 +157,8 @@ translator.trans_choice('auth.attempts', 25, { number: 25 });
 
 ### Transforming replacement parameters
 
-Like in Laravel's functionality, you can transform your parameters to upper case, or convert
-only the first character to capital letter. All you need to do, to modify your placeholders.
+Like Laravel, you can transform replacement values to uppercase or capitalize only the first letter.
+You only need to change the placeholder casing.
 
 ```php
 [
@@ -179,7 +182,7 @@ translator.trans('messages.goodbye', { name: 'pine' });
 ### Package translations
 
 Thanks to the idea of [Jonathan](https://github.com/sardoj), package translations are supported by default.
-You can access to the translations as in Laravel, using the predefined namespace.
+You can access package translations the same way you do in Laravel, using the predefined namespace.
 
 ```js
 translator.trans('courier::messages.message');
@@ -187,26 +190,26 @@ translator.trans('courier::messages.message');
 
 ## Multiple locales
 
-Multiple locales are supported. You can change the application's locale anytime.
-Behind the scenes the proper translations will be rendered, if it exists.
+Multiple locales are supported. You can change the application's locale at any time.
+Behind the scenes, the correct translations are rendered when they exist.
 
 ## Fallback locales
 
-If there are no translations is not available in the current language,
-the package will look for the fallback locale's translations.
-If there is no translations available in the fallback locale, the missing translations won't appear.
+If translations are not available in the current locale,
+the package will look for translations in the fallback locale.
+If they are not available there either, the missing translations will not be rendered.
 
 ## Performance
 
-The translations are generated when the views are compiled.
-It means they are cached and stored as strings in the compiled views.
-It's much more performance friendly than generating them on runtime or running and AJAX request to fetch the translations.
+Translations are generated when the views are compiled.
+That means they are cached and stored as strings in the compiled views.
+This is much more efficient than generating them at runtime or making an AJAX request to fetch them.
 
-Behind the scenes there is a switch - case that determines which translations should be present, based on the current locale.
-This way only the current translations are pushed to the window object and not all of them.
+Behind the scenes, a switch statement determines which translations should be present based on the current locale.
+This way, only the current locale's translations are pushed to the `window` object instead of all translations.
 
-> Note: On local environment the cached views are getting cleared to keep translations fresh.
+> Note: In the local environment, cached views are cleared to keep translations fresh.
 
 ## Contribute
 
-If you found a bug or you have an idea connecting the package, feel free to open an issue.
+If you find a bug or have an idea for the package, feel free to open an issue.
diff --git a/resources/js/I18n.js b/resources/js/I18n.js
index bbe7457..10dcfbe 100644
--- a/resources/js/I18n.js
+++ b/resources/js/I18n.js
@@ -33,43 +33,84 @@ export default class I18n
      */
     trans_choice(key, count = 1, replace = {})
     {
-        let translations = this._extract(key, '|').split('|'), translation;
+        let segments = this._extract(key).toString().split('|');
+        let translation = this._extractChoice(segments, count);
 
-        translations.some(t => translation = this._match(t, count));
+        return this._replace(translation, { count, ...replace });
+    }
 
-        translation = translation || (count > 1 ? translations[1] : translations[0]);
+    /**
+     * Extract a translation string using inline conditions.
+     *
+     * @param  {string[]}  segments
+     * @param  {number}  count
+     * @return {string}
+     */
+    _extractChoice(segments, count)
+    {
+        let translation;
+
+        segments.some(segment => {
+            translation = this._extractFromString(segment, count);
+
+            return translation !== null;
+        });
+
+        if (translation !== null && translation !== undefined) {
+            return translation.trim();
+        }
 
-        translation = translation.replace(/\[.*?\]|\{.*?\}/, '');
+        segments = this._stripConditions(segments);
 
-        return this._replace(translation, replace);
+        if (segments.length === 1 || count == 1 || segments[1] === undefined) {
+            return segments[0].trim();
+        }
+
+        return segments[1].trim();
     }
 
     /**
-     * Match the translation limit with the count.
+     * Get the translation string if the condition matches.
      *
      * @param  {string}  translation
      * @param  {number}  count
      * @return {string|null}
      */
-    _match(translation, count)
+    _extractFromString(translation, count)
     {
-        let match = translation.match(/^[\{\[]([^\[\]\{\}]*)[\}\]](.*)/);
+        let match = translation.match(/^[\{\[]([^\[\]\{\}]*)[\}\]]([\s\S]*)/);
 
-        if (! match) return;
+        if (! match || match.length !== 3) {
+            return null;
+        }
 
-        if (match[1].includes(',')) {
-            let [from, to] = match[1].split(',', 2);
+        let condition = match[1];
+        let value = match[2];
+
+        if (condition.includes(',')) {
+            let [from, to] = condition.split(',', 2);
 
             if (to === '*' && count >= from) {
-                return match[2];
+                return value;
             } else if (from === '*' && count <= to) {
-                return match[2];
+                return value;
             } else if (count >= from && count <= to) {
-                return match[2];
+                return value;
             }
         }
 
-        return match[1] == count ? match[2] : null;
+        return condition == count ? value : null;
+    }
+
+    /**
+     * Strip the inline conditions from each segment, just leaving the text.
+     *
+     * @param  {string[]}  segments
+     * @return {string[]}
+     */
+    _stripConditions(segments)
+    {
+        return segments.map(segment => segment.replace(/^[\{\[]([^\[\]\{\}]*)[\}\]]/, ''));
     }
 
     /**
@@ -95,25 +136,26 @@ export default class I18n
                 );
         }
 
-        return translation.toString().trim()
+        return translation.toString().trim();
     }
 
     /**
      * Extract values from objects by dot notation.
      *
      * @param  {string}  key
-     * @param  {mixed}  value
      * @return {mixed}
      */
-    _extract(key, value = null)
+    _extract(key)
     {
-        let path = key.toString().split('::'),
-            keys = path.pop().toString().split('.');
+        let path = key.toString().split('::');
+        let keys = path.pop().toString().split('.');
 
         if (path.length > 0) {
             path[0] += '::';
         }
 
-        return path.concat(keys).reduce((t, i) => t[i] || (value || key), window[this.key]);
+        return path.concat(keys).reduce((translations, index) => {
+            return translations && translations[index] !== undefined ? translations[index] : key;
+        }, window[this.key]);
     }
 }
diff --git a/tests/I18n.test.mjs b/tests/I18n.test.mjs
new file mode 100644
index 0000000..c438d03
--- /dev/null
+++ b/tests/I18n.test.mjs
@@ -0,0 +1,88 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { readFile } from 'node:fs/promises';
+
+const source = await readFile(new URL('../resources/js/I18n.js', import.meta.url), 'utf8');
+const { default: I18n } = await import(`data:text/javascript,${encodeURIComponent(source)}`);
+
+function makeTranslator({
+    translations = {},
+    key = 'translations',
+} = {}) {
+    globalThis.window = globalThis;
+    globalThis[key] = translations;
+
+    return new I18n(key);
+}
+
+test.afterEach(() => {
+    delete globalThis.translations;
+    delete globalThis.custom;
+    delete globalThis.window;
+});
+
+test('trans_choice matches fallback for a single segment and replaces :count', () => {
+    let i18n = makeTranslator();
+
+    assert.equal(i18n.trans_choice(':count messages', 2), '2 messages');
+});
+
+test('trans_choice keeps explicit selector behavior', () => {
+    let i18n = makeTranslator();
+
+    let cases = [
+        ['first', '{0}  first|{1}second', 0],
+        ['first', '{1}first|{2}second', 1],
+        ['second', '{1}first|{2}second', 2],
+        ['', '{0}|{1}second', 0],
+        ['', '{0}first|{1}', 1],
+        ['first', '{1.3}first|{2.3}second', 1.3],
+        ['second', '{1.3}first|{2.3}second', 2.3],
+        ['second', '[4,*]first|[1,3]second', 1],
+        ['first', '[4,*]first|[1,3]second', 100],
+        ['second', '[5,*]first|[*,4]second', 0],
+        ['first', '{0}first|[1,3]second|[4,*]third', 0],
+        ['second', '{0}first|[1,3]second|[4,*]third', 1],
+        ['third', '{0}first|[1,3]second|[4,*]third', 9],
+        ['first', '{0}  first | { 1 } second', 0],
+        ['first', '[4,*]first | [1,3]second', 100],
+    ];
+
+    for (let [expected, line, count] of cases) {
+        assert.equal(i18n.trans_choice(line, count), expected);
+    }
+});
+
+test('trans_choice keeps multiline explicit selections intact', () => {
+    let i18n = makeTranslator();
+
+    assert.equal(
+        i18n.trans_choice('{1}first\n            line|{2}second', 1),
+        'first\n            line'
+    );
+});
+
+test('trans_choice falls back to first form for 1 and second form otherwise', () => {
+    let i18n = makeTranslator();
+
+    assert.equal(i18n.trans_choice('first|second', 1), 'first');
+    assert.equal(i18n.trans_choice('first|second', 0), 'second');
+    assert.equal(i18n.trans_choice('first|second', 9), 'second');
+});
+
+test('trans_choice falls back to the first form when the second slot is missing', () => {
+    let i18n = makeTranslator();
+
+    assert.equal(i18n.trans_choice('first', 1), 'first');
+    assert.equal(i18n.trans_choice('first', 10), 'first');
+});
+
+test('custom translation keys still work with simplified fallback behavior', () => {
+    let i18n = makeTranslator({
+        key: 'custom',
+        translations: { auth: { attempts: 'first|second|third' } },
+    });
+
+    assert.equal(i18n.trans_choice('auth.attempts', 1), 'first');
+    assert.equal(i18n.trans_choice('auth.attempts', 5), 'second');
+});