Fixes #32, Adds function length metric

bin/php-doc-check

@@ -42,6 +42,7 @@ $lexer = new \PhpParser\Lexer\Emulative(
     array(
         'usedAttributes' => array(
             'startLine',
+            'endLine',
             'comments',
         ),
     )

src/AnalysableFile.php

@@ -14,6 +14,7 @@ class AnalysableFile implements \JsonSerializable
         'cognitive'  => '\NdB\PhpDocCheck\Metrics\CognitiveComplexity',
         'metrics.deprecated.category'  => '\NdB\PhpDocCheck\Metrics\CategoryDeprecated',
         'metrics.deprecated.subpackage'  => '\NdB\PhpDocCheck\Metrics\SubpackageDeprecated',
+        'metrics.complexity.length'  => '\NdB\PhpDocCheck\Metrics\FunctionLength',
         'cyclomatic' => '\NdB\PhpDocCheck\Metrics\CyclomaticComplexity'
     );
 

src/Metrics/FunctionLength.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace NdB\PhpDocCheck\Metrics;
+
+final class FunctionLength implements Metric
+{
+    public $value = 0;
+
+    const LINES_PER_POINT = 5;
+
+    public function getMessage():string
+    {
+        return '%1$s has a length score of %2$d. It is recommended to document long functions.';
+    }
+
+    public function getName():string
+    {
+        return 'metrics.complexity.length';
+    }
+
+    public function getValue(\PhpParser\Node $node):int
+    {
+        if (!empty($node->getDocComment())) {
+            return 0;
+        }
+        return ( $node->getEndLine() - $node->getStartLine() ) / self::LINES_PER_POINT;
+    }
+
+    public function jsonSerialize() : array
+    {
+        return array(
+            'name'=>$this->getName(),
+            'value'=>$this->value
+        );
+    }
+}