Test what trans_choice() really returns

How Laravel picks a plural form

trans_choice('cart.items', $count) loads the line, splits it on | and hands it to Illuminate\Translation\MessageSelector. The selector works in two passes. First it looks for an explicit condition at the start of any segment: {0}, {1}, [2,19] or [20,*]. The first segment whose condition matches wins, and its text is trimmed. Only when nothing matches does the second pass run: the conditions are stripped and getPluralIndex() turns the locale and number into an index, using a table of rules Laravel inherited from Zend Framework. If the line has no segment at that index, Laravel returns the first one.

After a form is chosen, :count is replaced with the number unless you pass your own count, and every placeholder also works in :Name (first letter upper-cased) and :NAME (all caps) variants. This page builds a Translator around your line and calls choice(), so none of that is re-implemented: the index column is read from the same selector.

The hyphen trap: pt_BR works, pt-BR does not

The rule table in MessageSelector is a switch over locale codes such as pt, pt_BR and de_DE. Anything it does not list falls to the default branch, which returns index 0. A hyphenated code like pt-BR or en-US, the format browsers send in Accept-Language, is not in the table, so every number gets the first form: "5 maçã" instead of "5 maçãs". There is no exception and no log entry. Try the pt-BR example above, then change the locale to pt_BR. If your locale comes from a URL segment or a header, normalise it with str_replace('-', '_', $locale) before calling App::setLocale(), and name the lang folder to match.

When you silently get the first form

• The locale is unknown to the table: a hyphenated code, a typo, or a language Laravel does not list.
• The line has fewer forms than the language needs. Polish has three under Laravel's rules, so jabłko|jabłka prints "jabłko" for 5, 0 and 1000. The tester highlights these rows.
• The line has a single segment, which is always returned as-is.

Fractions and explicit ranges

With {0} No apples|{1} One apple|[2,*] :count apples, the number 1.5 matches none of the conditions, so Laravel falls back to the English rule, which returns index 1. Index 1 is the second segment, "One apple", with a leading space because the plural pass does not trim. If fractional counts are possible, cover them with a range such as [1.01,*] or round the number before calling trans_choice().

Worked example: Polish apples

Load the Polish example. Laravel's rule for pl returns index 0 for exactly 1, index 1 when the last digit is 2, 3 or 4 (but not 12, 13 or 14), and index 2 for everything else. So 22 prints "22 jabłka", while 12, 25 and 0 print "jabłek". Fractions are cast to an integer before the modulo checks, which puts 1.5 on index 2. Once the table looks right, lock it in with a test so a translator cannot break it later:

it('pluralizes apples in Polish', function () {
    expect(trans_choice('shop.apples', 1, [], 'pl'))->toBe('1 jabłko')
        ->and(trans_choice('shop.apples', 22, [], 'pl'))->toBe('22 jabłka')
        ->and(trans_choice('shop.apples', 25, [], 'pl'))->toBe('25 jabłek');
});

Laravel's table is not CLDR, so it can disagree with what the Pluralization Tester reports for the same language. The background is in Laravel trans_choice() in depth and in the glossary entry on pluralization. The language guides list the exact forms for Polish, Russian, Arabic, Portuguese, French and Czech.