Bug Description

As reported by one user in the forums, there are deprecation notices stemming from the plugin, and not part of any third party dependency. These can be seem below:

E_DEPRECATED htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in file /wp-content/plugins/google-site-kit/includes/Core/Authentication/Clients/OAuth_Client.php on line 403

E_DEPRECATED strtotime(): Passing null to parameter #1 ($datetime) of type string is deprecated in file /wp-content/plugins/google-site-kit/includes/Modules/Analytics_4/Report.php on line 112

E_DEPRECATED htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in file /wp-content/plugins/google-site-kit/includes/Core/Authentication/Setup.php on line 234

Testing underway, with more insights and log files to be provided.

Do not alter or remove anything below. The following sections will be managed by moderators only.

Acceptance criteria

• The code base should be audited for usage that raises PHP deprecations
• PHP deprecation messages should cause tests to fail

Implementation Brief

• Configure PHPUnit to enable the convertDeprecationsToExceptions attribute
• Run unit tests using PHP 8.1 and address all failures

Test Coverage

• No new coverage to add
• If possible, update PHPUnit test matrix to run on PHP 8.1 or 8.2 instead of 8.0

QA Brief

• Using a web server running PHP 8.1 (or above)
• Do overall smoke testing of the Site Kit and general modules
• Verify that there are no deprecation or other notices in the error log

Changelog entry

• Fix PHP 8.1 deprecation notices.