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

@@ -156,3 +156,14 @@ MyNamespace\parse_url( 'http://example.com/' );
 \MyNamespace\json_encode( $data );
 namespace\unlink(); // The sniff should start flagging this once it can resolve relative namespaces.
 namespace\Sub\strip_tags( $string );
+
+/*
+ * 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->GET_HOME_PATH() . 'subdir/file.inc' );
+file_get_contents( $this?->plugin_dir_path() . 'subdir/file.inc' );
+file_get_contents( MyClass::ABSPATH . 'subdir/file.inc' );
+file_get_contents( $this->WPMU_PLUGIN_DIR . 'subdir/file.inc' );
+file_get_contents( $this?->TEMPLATEPATH . 'subdir/file.inc' );

WordPress/Tests/WP/AlternativeFunctionsUnitTest.php

@@ -90,6 +90,12 @@ public function getWarningList() {
 			142 => 1,
 			146 => 1,
 			154 => 1,
+			164 => 1,
+			165 => 1,
+			166 => 1,
+			167 => 1,
+			168 => 1,
+			169 => 1,
 		);
 	}
 }