WP/AlternativeFunctions: fix handling of FQN references to global stream constants

This fixes handling of fully qualified name (FQN) references to the global PHP stream constants `\STDIN`, `\STDOUT`, and `\STDERR` by normalizing the passed parameter before checking it against the allowed list.

Tests have been added to cover all namespace forms of references to the global PHP stream constants.

Author: rodrigoprimo

WordPress/Sniffs/WP/AlternativeFunctionsSniff.php

@@ -354,6 +354,11 @@ public function process_matched_token( $stackPtr, $group_name, $matched_content
 	protected function is_local_data_stream( $clean_param_value ) {
 
 		$stripped = TextStrings::stripQuotes( $clean_param_value );
+
+		if ( strpos( $clean_param_value, '\\' ) === 0 ) {
+			$clean_param_value = substr( $clean_param_value, 1 );
+		}
+
 		if ( isset( $this->allowed_local_streams[ $stripped ] )
 			|| isset( $this->allowed_local_stream_constants[ $clean_param_value ] )
 		) {

WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc

@@ -167,3 +167,16 @@ 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' );
+
+/*
+ * Safeguard correct handling of namespaced variants of STDIN/STDOUT/STDERR constants.
+ *
+ * Note: passing stream resources to these functions is not valid PHP and will be addressed in
+ * https://github.com/WordPress/WordPress-Coding-Standards/issues/2602. These tests document the current behavior of the
+ * sniff.
+ */
+fopen( \STDIN, 'r' );
+file_put_contents( MyNamespace\STDOUT, $data );
+file_get_contents( \MyNamespace\STDIN );
+file_put_contents( namespace\STDERR, $data ); // The sniff should not flag this once it can resolve relative namespaces.
+readfile( namespace\Sub\STDIN );

WordPress/Tests/WP/AlternativeFunctionsUnitTest.php

@@ -96,6 +96,10 @@ public function getWarningList() {
 			167 => 1,
 			168 => 1,
 			169 => 1,
+			179 => 1,
+			180 => 1,
+			181 => 1,
+			182 => 1,
 		);
 	}
 }