Remove deprecated FILTER_SANITIZE_STRING usage.

[rawdreeg]

Changes proposed in this Pull Request:

Remove deprecated FILTER_SANITIZE_STRING usage.

Closes #2588.

str_truncate, str_exists, str_truncate and other related string helper methods in the WooCommerce\Facebook\Framework\Helper class had a fallback for cases where the mbstring PHP extension was not available. This fallback str_to_ascii method would throw a deprecate warning notice because of its use of the FILTER_SANITIZE_STRING constant.

I have considered removing the self::multibyte_loaded() check and falling back on the WP core polyfill. But some mb functions do not have polyfills in the core like mb_strpos. This will require including and loading something like https://github.com/symfony/polyfill-mbstring.

We can look at this when we work on the cleanup task: #2705.

Here, I re-implement str_ascii without filter_var. This keeps printable ASCII chars, stripping out everything from 0-31 and 127-255,.

• Do the changed files pass phpcs checks? Please remove phpcs:ignore comments in changed files and fix any issues, or delete if not practical.

Screenshots:

Detailed test instructions:

To reproduce:

1. Ensure your local server has PHP 8.1 or higher.
2. Enable WP_DEBUG and WP_DEBUG_LOG
3. Change this line to return false:

   facebook-for-woocommerce/includes/Framework/Helper.php

   Line 155 in f8b103d

   return extension_loaded( 'mbstring' );

4. Configure Facebook for WooCommerce, notice the deprecation warning notices in your log file

Check out this branch.

You can try to sync a product by editing it; for example, no warning notice should be thrown.

Changelog entry

Fix - Remove deprecated FILTER_SANITIZE_STRING usage.

[layoutd]

👍🏻 LGTM thanks @rawdreeg. Test instructions work correctly.

I wasn't very familiar with the functionality so I double-checked the new implementation with some simple test cases and all 🟢

    $test_cases = [
        "Hello World!" => "Hello World!",
        "Hello\x00 World!" => "Hello World!",
        "Hello\x7F World!" => "Hello World!",
        "Hello\x1F World!" => "Hello World!",
        "Hello\x80 World!" => "Hello World!",
        "Hello\nWorld!" => "HelloWorld!", // Newline character removed
    ];