Strings in block.json are not translated from PO file if no other javascript strings are present.

[WilliamLeeks]

Bug Report

• ✅ Yes, I reviewed the contribution guidelines.

Describe the current, buggy behavior

Strings in block.json are detected by the make-pot command and added to the POT file. These can eb translated and added to a PO file. However, if block.json is the only non-PHP source of localized strings, running make-json outputs zero files.

Describe how other contributors can replicate this bug

• Create a simple block as a plugin, including a title and description in the block.json file.
• Make sure the plugin has a languages folder and its textdomain is loaded using load_plugin_textdomain.
• Run make-pot in the plugin, to generate a POT file, which will contain entries for the block.json title and description.
• Translate the title and description (for example using POEdit) and save those translations as PO/MO files in the plugin’s languages folder.
• Run make-json in the plugin. This will generate zero files, and the translations for the block title/description will not be used.

Describe what you would expect as the correct outcome

I would expect the make-json command to output a JSON file so that the localized strings from block.json can be loaded.

(I am aware it is possible to register a block using localized strings in registerBlockType, but this would mean a duplication of the strings from block.json which does not feel like the intended behaviour.)

[swissspidy]

How are you registering your block? Please share some minimal reproduction code as a Gist or so, just so we're on the same page.

make-json is not supposed to include block.json files. make-json is for creating translation files for your JavaScript (.js) files.

If you register your block in PHP using register_block_type, then the translations from your MO file will be involved, and the block.json strings will be in there. And if you do import './block.json in your JS file to call registerBlockType, then you would have JS source files.