NewClassesSniff incorrectly reports imported classes as missing (#1695)

NewClassesSniff incorrectly reports imported classes as missing

* Record `use`s in attribute and ignores them when checking for usage
  of PHP default classes.

PHPCompatibility/Sniffs/Classes/NewClassesSniff.php

@@ -20,6 +20,7 @@
 use PHPCSUtils\Utils\ControlStructures;
 use PHPCSUtils\Utils\FunctionDeclarations;
 use PHPCSUtils\Utils\Scopes;
+use PHPCSUtils\Utils\UseStatements;
 use PHPCSUtils\Utils\Variables;
 
 /**
@@ -1095,6 +1096,29 @@ class NewClassesSniff extends Sniff
         ],
     ];
 
+    /**
+     * Current file being scanned.
+     *
+     * @since 10.0.0
+     *
+     * @var string
+     */
+    private $currentFile = '';
+
+    /**
+     * Stores information about imported, namespaced classes with names which are also in use by PHP.
+     *
+     * When those classes are used, they do not point to the PHP classes, but to the
+     * namespaced, imported class and those usages should be ignored by the sniff.
+     *
+     * The array is indexed by unqualified class names in lower case. The value is always true.
+     * It is structured this way to utilize the isset() function for faster lookups.
+     *
+     * @since 10.0.0
+     *
+     * @var array<string,true>
+     */
+    private $importedClasses = [];
 
     /**
      * Returns an array of tokens this test wants to listen for.
@@ -1123,6 +1147,7 @@ public function register()
         $this->newClasses = \array_merge($this->newClasses, $this->newExceptions);
 
         $targets = [
+            \T_USE,
             \T_NEW,
             \T_CLASS,
             \T_ANON_CLASS,
@@ -1150,9 +1175,20 @@ public function register()
      */
     public function process(File $phpcsFile, $stackPtr)
     {
+        $fileName = $phpcsFile->getFilename();
+        if ($this->currentFile !== $fileName) {
+            // Reset the properties for each new file.
+            $this->currentFile     = $fileName;
+            $this->importedClasses = [];
+        }
+
         $tokens = $phpcsFile->getTokens();
 
         switch ($tokens[$stackPtr]['code']) {
+            case \T_USE:
+                $this->processUseToken($phpcsFile, $stackPtr);
+                break;
+
             case \T_VARIABLE:
                 $this->processVariableToken($phpcsFile, $stackPtr);
                 break;
@@ -1373,6 +1409,38 @@ private function processCatchToken(File $phpcsFile, $stackPtr)
         }
     }
 
+    /**
+     * Processes this test for when a use token is encountered.
+     *
+     * - Save imported classes for later use.
+     *
+     * @since 10.0.0
+     *
+     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
+     * @param int                         $stackPtr  The position of the current token in
+     *                                               the stack passed in $tokens.
+     *
+     * @return void
+     */
+    private function processUseToken(File $phpcsFile, $stackPtr)
+    {
+        if (!UseStatements::isImportUse($phpcsFile, $stackPtr)) {
+            return;
+        }
+
+        $splitUseStatement = UseStatements::splitImportUseStatement($phpcsFile, $stackPtr);
+
+        foreach ($splitUseStatement['name'] as $name => $fullyQualifiedName) {
+            $lowerFullyQualifiedName = strtolower($fullyQualifiedName);
+
+            if (isset($this->newClasses[$lowerFullyQualifiedName])) {
+                continue;
+            }
+
+            $this->importedClasses[strtolower($name)] = true;
+        }
+    }
+
 
     /**
      * Handle the retrieval of relevant information and - if necessary - throwing of an
@@ -1389,6 +1457,10 @@ private function processCatchToken(File $phpcsFile, $stackPtr)
      */
     protected function handleFeature(File $phpcsFile, $stackPtr, array $itemInfo)
     {
+        if (isset($this->importedClasses[$itemInfo['nameLc']])) {
+            return;
+        }
+
         $itemArray   = $this->newClasses[$itemInfo['nameLc']];
         $versionInfo = $this->getVersionInfo($itemArray);
 

PHPCompatibility/Tests/Classes/NewClassesUnitTest.php

@@ -334,4 +334,31 @@ public function testNoViolationsInFileOnValidVersion()
         $file = $this->sniffFile(__FILE__, '99.0'); // High version beyond newest addition.
         $this->assertNoViolation($file);
     }
+
+    /**
+     * If classes with same name are used in other namespaces, they should not be flagged.
+     *
+     * @return void
+     */
+    public function testNoViolationsInFileIfOtherNamespace()
+    {
+        $file          = $this->sniffFile(__DIR__ . '/NewClassesUsesUnitTest.inc', '4.4');
+        $sharedRuleSet = $file->ruleset;
+        $sharedConfig  = $file->config;
+
+        $forgedLocalFile = new \PHP_CodeSniffer\Files\LocalFile(
+            realpath(__DIR__ . '/NewClassesUsesNoLeakUnitTest.inc'),
+            $sharedRuleSet,
+            $sharedConfig
+        );
+        $forgedLocalFile->parse();
+        $forgedLocalFile->process();
+
+        $this->assertNoViolation($file);
+        $this->assertError(
+            $forgedLocalFile,
+            3,
+            'The built-in class ArrayObject is not present in PHP version 4.4 or earlier'
+        );
+    }
 }

PHPCompatibility/Tests/Classes/NewClassesUsesNoLeakUnitTest.inc

@@ -0,0 +1,3 @@
+<?php
+
+new ArrayObject();