Filter: files without extension are no longer ignored if the path is passed in directly

phpcs.xml.dist

@@ -4,7 +4,8 @@
 
     <file>autoload.php</file>
     <file>requirements.php</file>
-    <file>bin</file>
+    <file>bin/phpcs</file>
+    <file>bin/phpcbf</file>
     <file>scripts</file>
     <file>src</file>
     <file>tests</file>

src/Filters/Filter.php

@@ -27,6 +27,15 @@ class Filter extends RecursiveFilterIterator
      */
     protected $basedir = null;
 
+    /**
+     * Whether the basedir is a file or a directory.
+     *
+     * TRUE if the basedir is actually a directory.
+     *
+     * @var boolean
+     */
+    protected $isBasedirDir = false;
+
     /**
      * The config data for the run.
      *
@@ -82,6 +91,10 @@ public function __construct($iterator, $basedir, Config $config, Ruleset $rulese
         $this->config  = $config;
         $this->ruleset = $ruleset;
 
+        if (is_dir($basedir) === true || Common::isPharFile($basedir) === true) {
+            $this->isBasedirDir = true;
+        }
+
     }//end __construct()
 
 
@@ -172,7 +185,17 @@ protected function shouldProcessFile($path)
         $fileName  = basename($path);
         $fileParts = explode('.', $fileName);
         if ($fileParts[0] === $fileName || $fileParts[0] === '') {
-            return false;
+            if ($this->isBasedirDir === true) {
+                // We are recursing a directory, so ignore any
+                // files with no extension.
+                return false;
+            }
+
+            // We are processing a single file, so always
+            // accept files with no extension as they have been
+            // explicitly requested and there is no config setting
+            // to ignore them.
+            return true;
         }
 
         // Checking multi-part file extensions, so need to create a

tests/Core/Filters/Filter/ShouldProcessFileWithoutExtensionTest.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * Tests for the \PHP_CodeSniffer\Filters\Filter class.
+ *
+ * @copyright 2025 PHPCSStandards Contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\Filters\Filter;
+
+use PHP_CodeSniffer\Filters\Filter;
+use PHP_CodeSniffer\Tests\Core\Filters\AbstractFilterTestCase;
+use RecursiveArrayIterator;
+
+/**
+ * Tests handling of files without extension.
+ *
+ * @covers \PHP_CodeSniffer\Filters\Filter
+ */
+final class ShouldProcessFileWithoutExtensionTest extends AbstractFilterTestCase
+{
+
+
+    /**
+     * Verify that if a file without file extension is explicitly requested for scan, it is accepted.
+     *
+     * @return void
+     */
+    public function testFileWithoutExtensionIsAcceptedWhenExplicitlyRequested()
+    {
+        $fileWithoutExt = self::getBaseDir().'/bin/phpcs';
+
+        $fakeDI = new RecursiveArrayIterator([$fileWithoutExt]);
+        $filter = new Filter($fakeDI, $fileWithoutExt, self::$config, self::$ruleset);
+
+        $this->assertSame([$fileWithoutExt], $this->getFilteredResultsAsArray($filter));
+
+    }//end testFileWithoutExtensionIsAcceptedWhenExplicitlyRequested()
+
+
+    /**
+     * Verify that when (recursively) scanning a directory, files without extension are filtered out.
+     *
+     * @return void
+     */
+    public function testFileWithoutExtensionIsRejectedWhenRecursingDirectory()
+    {
+        $baseDir      = self::getBaseDir();
+        $fakeFileList = [
+            $baseDir.'/autoload.php',
+            $baseDir.'/bin',
+            $baseDir.'/bin/phpcs',
+            $baseDir.'/scripts',
+            $baseDir.'/scripts/build-phar.php',
+        ];
+        $fakeDI       = new RecursiveArrayIterator($fakeFileList);
+        $filter       = new Filter($fakeDI, self::getBaseDir(), self::$config, self::$ruleset);
+
+        $expectedOutput = [
+            $baseDir.'/autoload.php',
+            $baseDir.'/bin',
+            $baseDir.'/scripts',
+            $baseDir.'/scripts/build-phar.php',
+        ];
+
+        $this->assertSame($expectedOutput, $this->getFilteredResultsAsArray($filter));
+
+    }//end testFileWithoutExtensionIsRejectedWhenRecursingDirectory()
+
+
+}//end class