Wrong usage of _n() in WP 5.9 beta 3 translatable strings

[audrasjb]

Description

This issue is copy pasted from https://core.trac.wordpress.org/ticket/54638.
Thanks @tobifjellner for the report.

---

The new code for WordPress contains three instances where the "Template Part"/"Template Parts" string pair is used.
However, this is usage of _n() is incorrect.

If you want to handle just the singular and plural terms, then this should be handled in the code (if 1 == n then ...) and not by using _n()
Alternatively, if these strings are used together with the relevant number, then a placeholder for the count variable should be present in the string (i.e. printf)
Three references (to the current as-built package)
https://build.trac.wordpress.org/browser/trunk/wp-includes/js/dist/editor.js?marks=5220#L5220
const entityLabel = name === 'wp_template_part' ? Object(external_wp_i18n__n?)('Template Part', 'Template Parts', list.length) : entity.label; Set description based on type of entity.

https://build.trac.wordpress.org/browser/trunk/wp-includes/js/dist/block-library.js?marks=38830#L38830
https://build.trac.wordpress.org/browser/trunk/wp-includes/js/dist/editor.js?marks=5220#L5220

Step-by-step reproduction instructions

gutenberg/packages/editor/src/components/entities-saved-states/entity-type-list.js

Lines 52 to 55 in 5604b23

	const entityLabel =
	name === 'wp_template_part'
	? _n( 'Template Part', 'Template Parts', list.length )
	: entity.label;

Screenshots, screen recording, code snippet

No response

Environment info

• WordPress 5.9 beta 3
• Gutenberg not installed

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[ocean90]

The same applies to

gutenberg/packages/editor/src/components/entities-saved-states/entity-type-list.js

Lines 19 to 37 in 5604b23

	function getEntityDescription( entity, length ) {
	switch ( entity ) {
	case 'site':
	return _n(
	'This change will affect your whole site.',
	'These changes will affect your whole site.',
	length
	);
	case 'wp_template':
	return _n(
	'This change will affect pages and posts that use this template.',
	'These changes will affect pages and posts that use these templates.',
	length
	);
	case 'page':
	case 'post':
	return __( 'The following content has been modified.' );
	}
	}

.

[aristath]

Before making any changes to this behavior, please keep in mind that not all languages have the same concept of singular/plural as English. For example, there are languages where the plural for 2 is different than the plural for 3 and so on.

[Mamaduka]

I'm removing this issue from WP 5.9 project board since RC1 was released yesterday.

Let's try and land a fix for this in a minor release.

[Mamaduka]

Maybe we can drop the label and description variations altogether. Instead, use singular form for labels and plural for descriptions. All other labels are in this form, making it consistent.

@ockham, what do you think?

[ockham]

Hey @Mamaduka, thanks for the ping!

@aristath Your point about differentiating between plural forms is very valid and the reason why I used _n() in the first place. However, since we're dealing with "indefinite" plurals here (without a number), we might not have to worry about those. (E.g. I think pretty much all languages have a unique translation of These changes or these templates, where it's unknown if it's 2, 3, or x.) So we can probably use the if ( 1 === n ) { ... } else { ... } logic here.

That said, I was a bit surprised here since I believed that _n() was the right way of providing singular/plural versions of a string, even if it didn't include the number itself. I don't see that documented in the docs for the JS version of _n() -- is that something we need to add? I'd also be curious to learn why this is discouraged 🙂

@Mamaduka That could be an alternative; however, IIRC, I added the different versions for singular and plural in response to a designer's feedback that suggested doing so in order to make the copy correspond better to the number of changes (i.e. checkboxes) the user sees:

[Mamaduka]

Thanks for the feedback, @ockham.

I think ( 1 === n ) is a simple enough change for this case so that we can go with it. I will follow up with PR later today or tomorrow morning.

Re _n usage, I was only able to find this comment explaining the issue - https://developer.wordpress.org/reference/functions/_n/#comment-2397.