WP/AlternativeFunctions: improve regex to distinguish global WP constants/functions from non-WP class-based ones

This commit changes two regexes used to identify global WP constants and functions to prevent the sniff from incorrectly identifying class constants/methods with the same names as WordPress globals as being WordPress globals. This is done by adding a negative lookbehind to ensure the searched strings are not preceded by an object operator, null-safe object operator, or scope resolution operator.

Fixes part of 2603

Author: rodrigoprimo

WordPress/Sniffs/WP/AlternativeFunctionsSniff.php

@@ -283,7 +283,7 @@ public function process_matched_token( $stackPtr, $group_name, $matched_content
 				}
 
 				$contains_wp_path_constant = preg_match(
-					'`\b(?:ABSPATH|WP_(?:CONTENT|PLUGIN)_DIR|WPMU_PLUGIN_DIR|TEMPLATEPATH|STYLESHEETPATH|(?:MU)?PLUGINDIR)\b`',
+					'`(?<!\?->|->|::)\b(?:ABSPATH|WP_(?:CONTENT|PLUGIN)_DIR|WPMU_PLUGIN_DIR|TEMPLATEPATH|STYLESHEETPATH|(?:MU)?PLUGINDIR)\b`',
 					$filename_param['clean']
 				);
 				if ( 1 === $contains_wp_path_constant ) {
@@ -292,7 +292,7 @@ public function process_matched_token( $stackPtr, $group_name, $matched_content
 				}
 
 				$contains_wp_path_function_call = preg_match(
-					'`(?:get_home_path|plugin_dir_path|get_(?:stylesheet|template)_directory|wp_upload_dir)\s*\(`i',
+					'`(?<!\?->|->|::)(?:get_home_path|plugin_dir_path|get_(?:stylesheet|template)_directory|wp_upload_dir)\s*\(`i',
 					$filename_param['clean']
 				);
 				if ( 1 === $contains_wp_path_function_call ) {

WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc

@@ -171,3 +171,14 @@ file_get_contents(\ABSPATH . 'wp-admin/css/some-file.css');
 file_get_contents(MyNamespace\ABSPATH . 'wp-admin/css/some-file.css');
 file_get_contents(\MyNamespace\ABSPATH . 'wp-admin/css/some-file.css');
 file_get_contents(namespace\ABSPATH . 'wp-admin/css/some-file.css');
+
+/*
+ * Safeguard that the sniff does not incorrectly ignore class methods/constants with the same
+ * name as WordPress global functions/constants when used in file_get_contents().
+ */
+file_get_contents(MyClass::wp_upload_dir() . 'subdir/file.inc');
+file_get_contents($this->wp_upload_dir() . 'subdir/file.inc');
+file_get_contents($this?->wp_upload_dir() . 'subdir/file.inc');
+file_get_contents(MyClass::ABSPATH . 'subdir/file.inc');
+file_get_contents($this->ABSPATH . 'subdir/file.inc');
+file_get_contents($this?->ABSPATH . 'subdir/file.inc');

WordPress/Tests/WP/AlternativeFunctionsUnitTest.php

@@ -90,6 +90,12 @@ public function getWarningList() {
 			142 => 1,
 			146 => 1,
 			154 => 1,
+			179 => 1,
+			180 => 1,
+			181 => 1,
+			182 => 1,
+			183 => 1,
+			184 => 1,
 		);
 	}
 }