Validate against PHP 8.1 and Wordpress 6.1

[signosis]

The current plugin has not been validated to work with WordPress 6.1 and PHP 8.1. With PHP 7.4 being EOF in 3 Months what steps need to be taken to update this plugin?

[signosis]

Issues with json.php Phan reports the following general issue with PHP 7.4 and PHP 8.1

UndefError PhanUndeclaredProperty Reference to undeclared property \Services_JSON->use

CompatError PhanCompatibleDimAlternativeSyntax Array and string offset access syntax with curly braces is deprecated in PHP 7.4. Use square brackets instead. Seen for $utf16{0}, Seen for $chrs{$c} , Seen for $str{0}, Seen for $chrs{++$c}

UndefError PhanPossiblyUndeclaredVariable Variable $arr, $obj, is possibly undeclared

UndefError PhanUndeclaredClassMethod Call to method isError from undeclared class \PEAR

[signosis]

Issues with WP-Mendeley.PHP Error	Issue	Conclusion
RedefineError	RedefineFunctionInternal	Function json_decode defined at tmp.php:51 was previously defined internally
RedefineError	RedefineFunctionInternal	Function json_encode defined at tmp.php:48 was previously defined internally
TypeError	NonClassMethodCall	Call to method formatWidget on non-class type null
UndefError	PossiblyUndeclaredVariable	Variable $secret is possibly undeclared
TypeError	TypeArraySuspiciousNull	Suspicious array access to $headers of type null
TypeError	TypeArraySuspiciousNull	Suspicious array access to $attrs of nullable type ?mixed
TypeError	TypeArraySuspiciousNull	Suspicious array access to $attrs of nullable type ?mixed|?non-empty-mixed
TypeError	TypeExpectedObjectPropAccessButGotNull	Expected an object instance when accessing an instance property, but saw an expression $result with type null=
TypeError	TypeInvalidRightOperandOfAdd	Invalid operator: right operand of + is ?string (expected array or number)
TypeError	TypeInvalidRightOperandOfAdd	Invalid operator: right operand of + is null (expected array or number)
TypeError	TypeMismatchArgumentInternal	Argument 1 ($haystack) is $tmps of type \the but \stristr() takes string
TypeError	TypeMismatchArgumentInternal	Argument 1 ($seconds) is $time_limit of type false|string but \set_time_limit() takes int
TypeError	TypeMismatchArgumentInternal	Argument 3 ($offset) is false of type false but \strpos() takes int
TypeError	TypeMismatchArgumentInternalReal	Argument 1 ($haystack) is $tag_arr of type null but \stristr() takes string
TypeError	TypeMismatchDimAssignment	When appending to a value of type array{}, found an array access index of type ?'Link'|?string, but expected the index to be of type int|string
TypeError	TypeMismatchReturnProbablyReal	Returning (($x . $concat_str) . $y) of type string but concatenate() is declared to return \the (no real type) (the inferred real return type has nothing in common with the declared phpdoc return type)
TypeError	TypeSuspiciousEcho	Suspicious argument $after_widget of type null= for an echo/print statement
TypeError	TypeSuspiciousEcho	Suspicious argument $before_widget of type null= for an echo/print statement
TypeError	TypeSuspiciousStringExpression	Suspicious type null= of a variable or expression $after_title used to build a string. (Expected type to be able to cast to a string)
TypeError	TypeSuspiciousStringExpression	Suspicious type null= of a variable or expression $before_title used to build a string. (Expected type to be able to cast to a string)
UndefError	UndeclaredClass	Reference to undeclared class \WP_Widget
UndefError	UndeclaredClassMethod	Call to method __construct from undeclared class \citeproc
UndefError	UndeclaredClassMethod	Call to method __construct from undeclared class \Services_JSON
UndefError	UndeclaredClassMethod	Call to method render from undeclared class \citeproc
UndefError	UndeclaredConstant	Reference to undeclared constant \ABSPATH. This will cause a thrown Error in php 8.0+.
UndefError	UndeclaredConstant	Reference to undeclared constant \WP_CONTENT_DIR. This will cause a thrown Error in php 8.0+.
UndefError	UndeclaredExtendedClass	Class extends undeclared class \WP_Widget
UndefError	UndeclaredFunction	Call to undeclared function __()
UndefError	UndeclaredFunction	Call to undeclared function _e()
UndefError	UndeclaredFunction	Call to undeclared function \add_action()
UndefError	UndeclaredFunction	Call to undeclared function \add_options_page()
UndefError	UndeclaredFunction	Call to undeclared function \add_shortcode()
UndefError	UndeclaredFunction	Call to undeclared function \admin_url()
UndefError	UndeclaredFunction	Call to undeclared function \apply_filters()
UndefError	UndeclaredFunction	Call to undeclared function \content_url()
UndefError	UndeclaredFunction	Call to undeclared function \dbDelta()
UndefError	UndeclaredFunction	Call to undeclared function \esc_attr()
UndefError	UndeclaredFunction	Call to undeclared function \get_option()
UndefError	UndeclaredFunction	Call to undeclared function \load_plugin_textdomain()
UndefError	UndeclaredFunction	Call to undeclared function \plugin_basename()
UndefError	UndeclaredFunction	Call to undeclared function \plugins_url()
UndefError	UndeclaredFunction	Call to undeclared function \register_widget()
UndefError	UndeclaredFunction	Call to undeclared function \update_option()
UndefError	UndeclaredFunction	Call to undeclared function \wp_enqueue_script()
UndefError	UndeclaredFunction	Call to undeclared function \wp_register_script()
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyCollectionWidget::get_field_id
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyCollectionWidget::get_field_name
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyOwnWidget::get_field_id
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyOwnWidget::get_field_name
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyPlugin::filesExistsInCache
UndefError	UndeclaredMethod	Call to undeclared method \MendeleyPlugin::setFailedToCache
UndefError	UndeclaredProperty	Reference to undeclared property \MendeleyPlugin->settings
UndefError	UndeclaredProperty	Reference to undeclared property \MendeleyPlugin->type_map
UndefError	UndeclaredTypeReturnType	Return type of comma_concatenate() is undeclared type \the
UndefError	UndeclaredTypeReturnType	Return type of comma_separated_names() is undeclared type \the
UndefError	UndeclaredTypeReturnType	Return type of concatenate() is undeclared type \the
UndefError	UndeclaredVariable	Variable $after_title, $after_widget, $before_title, $before_widget,$result,$tag_arr is undeclared