DB/DirectDatabaseQuery: fix handling of namespaced calls to cache functions

Before this change, the sniff was not properly differentiating between fully qualified calls to global WP cache functions and namespaced calls to non-WP functions with the same name as the WP functions.

In other words, the sniff was correctly identifying `\wp_cache_get()` as a WP cache function, but it was incorrectly identifying `MyNamespace\wp_cache_get()` as a WP cache function. This commit fixes this issue.

Author: rodrigoprimo

WordPress/Sniffs/DB/DirectDatabaseQuerySniff.php

@@ -235,6 +235,15 @@ public function process_token( $stackPtr ) {
 						continue;
 					}
 
+					// Skip if this is a non-global namespaced function call.
+					$prevNonEmpty = $this->phpcsFile->findPrevious( Tokens::$emptyTokens, ( $i - 1 ), null, true );
+					if ( \T_NS_SEPARATOR === $this->tokens[ $prevNonEmpty ]['code'] ) {
+						$prevPrevNonEmpty = $this->phpcsFile->findPrevious( Tokens::$emptyTokens, ( $prevNonEmpty - 1 ), null, true );
+						if ( \T_STRING === $this->tokens[ $prevPrevNonEmpty ]['code'] || \T_NAMESPACE === $this->tokens[ $prevPrevNonEmpty ]['code'] ) {
+							continue;
+						}
+					}
+
 					$content = strtolower( $this->tokens[ $i ]['content'] );
 
 					if ( isset( $this->cacheDeleteFunctions[ $content ] ) ) {

WordPress/Tests/DB/DirectDatabaseQueryUnitTest.1.inc

@@ -379,3 +379,47 @@ function methodNamesSameAsCacheFunctions() {
 
 	return $listofthings;
 }
+
+function fullyQualifiedCallsToCacheFunctions1() {
+    global $wpdb;
+
+    if ( ! ( $listofthings = \wp_cache_get( $foo ) ) ) {
+        $listofthings = $wpdb->get_col( 'SELECT something FROM somewhere WHERE someotherthing = 1' ); // Warning direct DB call.
+        \wp_cache_set( 'foo', $listofthings );
+    }
+
+    return $listofthings;
+}
+
+function fullyQualifiedCallsToCacheFunctions2() {
+	global $wpdb;
+
+	$wpdb->query( 'SELECT X FROM Y' ); // Warning direct DB call.
+	\wp_cache_delete( 'key', 'group' );
+}
+
+function callToNamespacedNonGlobalFunctions1() {
+	global $wpdb;
+
+	$listofthings = MyNamespace\wp_cache_get( $foo );
+	$listofthings = \MyNamespace\wp_cache_get( $foo );
+	$listofthings = namespace\wp_cache_get( $foo ); // The sniff should start considering this a valid WP cache function once it can resolve relative namespaces.
+
+	if ( ! $listofthings ) {
+		$listofthings = $wpdb->get_col( 'SELECT something FROM somewhere WHERE someotherthing = 1' ); // Warning x 2.
+		MyNamespace\wp_cache_set( 'foo', $listofthings );
+		\MyNamespace\wp_cache_set( 'foo', $listofthings );
+		namespace\wp_cache_set( 'foo', $listofthings ); // The sniff should start considering this a valid WP cache function once it can resolve relative namespaces.
+	}
+
+	return $listofthings;
+}
+
+function callToNamespacedNonGlobalFunctions2() {
+	global $wpdb;
+
+	$wpdb->query( 'SELECT X FROM Y' ); // Warning x 2.
+	MyNamespace\wp_cache_delete( 'key', 'group' );
+	\MyNamespace\wp_cache_delete( 'key', 'group' );
+	namespace\wp_cache_delete( 'key', 'group' ); // The sniff should start considering this a valid WP cache function once it can resolve relative namespaces.
+}

WordPress/Tests/DB/DirectDatabaseQueryUnitTest.php

@@ -99,6 +99,10 @@ public function getWarningList( $testFile = '' ) {
 					350 => 1,
 					364 => 2,
 					376 => 1,
+					387 => 1,
+					397 => 1,
+					409 => 2,
+					421 => 2,
 				);
 			default:
 				return array();