diff --git a/src/Formatter.php b/src/Formatter.php
index e83b5b0d..5f4744f8 100644
--- a/src/Formatter.php
+++ b/src/Formatter.php
@@ -3,56 +3,70 @@
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\{TextEdit, Range, Position, ErrorCode};
-use AdvancedJsonRpc\ResponseError;
+use LanguageServer\Protocol\ {
+    TextEdit, 
+    Range, 
+    Position
+};
 use PHP_CodeSniffer;
+use Exception;
 
-class Formatter
+abstract class Formatter
 {
     /**
+     * Generate array of TextEdit changes for content formatting.
      *
-     * @param string $content
-     * @param string $uri
+     * @param string $content source code to format
+     * @param string $uri URI of document
      *
      * @return \LanguageServer\Protocol\TextEdit[]
-     * @throws \AdvancedJsonRpc\ResponseError
+     * @throws \Exception
      */
-    public function format(string $content, string $uri)
+    public static function format(string $content, string $uri)
     {
         $path = uriToPath($uri);
         $cs = new PHP_CodeSniffer();
-        $cs->initStandard($this->findConfiguration($path));
+        $cs->initStandard(self::findConfiguration($path));
         $file = $cs->processFile(null, $content);
         $fixed = $file->fixer->fixFile();
         if (!$fixed && $file->getErrorCount() > 0) {
-            throw new ResponseError('Unable to format file', ErrorCode::INTERNAL_ERROR);
+            throw new Exception('Unable to format file');
         }
 
         $new = $file->fixer->getContents();
         if ($content === $new) {
             return [];
         }
-        return [new TextEdit(new Range(new Position(0, 0), $this->calculateEndPosition($content)), $new)];
+        return [new TextEdit(new Range(new Position(0, 0), self::calculateEndPosition($content)), $new)];
     }
 
     /**
-     * @param string $content
+     * Calculate position of last character.
+     * 
+     * @param string $content document as string
+     * 
      * @return \LanguageServer\Protocol\Position
      */
-    private function calculateEndPosition(string $content): Position
+    private static function calculateEndPosition(string $content): Position
     {
         $lines = explode("\n", $content);
         return new Position(count($lines) - 1, strlen(end($lines)));
     }
 
     /**
+     * Search for PHP_CodeSniffer configuration file at given directory or its parents. 
+     * If no configuration found then PSR2 standard is loaded by default. 
      *
-     * @param string $path
+     * @param string $path path to file or directory 
      * @return string[]
      */
-    private function findConfiguration(string $path)
+    private static function findConfiguration(string $path)
     {
-        $currentDir = dirname($path);
+        if (is_dir($path)) {
+            $currentDir = $path;
+        } else {
+            $currentDir = dirname($path);
+        }
         do {
             $default = $currentDir . DIRECTORY_SEPARATOR . 'phpcs.xml';
             if (is_file($default)) {
diff --git a/src/PhpDocument.php b/src/PhpDocument.php
index 6b3f3c84..507170e3 100644
--- a/src/PhpDocument.php
+++ b/src/PhpDocument.php
@@ -112,17 +112,16 @@ public function parse()
     }
 
     /**
-     * Returns this document as formatted text.
+     * Returns array of TextEdit changes to format this document.
      *
-     * @return string
+     * @return \LanguageServer\Protocol\TextEdit[]
      */
     public function getFormattedText()
     {
         if (empty($this->content)) {
             return [];
         }
-        $formatter = new Formatter();
-        return $formatter->format($this->content, $this->uri);
+        return Formatter::format($this->content, $this->uri);
     }
 
     /**
diff --git a/tests/FormatterTest.php b/tests/FormatterTest.php
index af7efd4b..a46f2ec7 100644
--- a/tests/FormatterTest.php
+++ b/tests/FormatterTest.php
@@ -11,21 +11,18 @@ class FormatterTest extends TestCase
 
     public function testFormat()
     {
-        $formatter = new Formatter();
-
         $input = file_get_contents(__DIR__ . '/../fixtures/format.php');
         $output = file_get_contents(__DIR__ . '/../fixtures/format_expected.php');
 
-        $edits = $formatter->format($input, 'file:///whatever');
+        $edits = Formatter::format($input, 'file:///whatever');
         $this->assertSame($output, $edits[0]->newText);
     }
 
     public function testFormatNoChange()
     {
-        $formatter = new Formatter();
         $expected = file_get_contents(__DIR__ . '/../fixtures/format_expected.php');
 
-        $edits = $formatter->format($expected, 'file:///whatever');
+        $edits = Formatter::format($expected, 'file:///whatever');
         $this->assertSame([], $edits);
     }
 }