Implement new max_nesting_level setting (#243)

thephpleague · Dec 30, 2017 · 57107ed · 57107ed
1 parent 68b1737
commit 57107ed
Show file tree

Hide file tree

Showing 5 changed files with 62 additions and 1 deletion.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,6 +10,7 @@ This release contains several breaking changes and a minimum PHP version bump -
 
 ### Added
 
+ - Added new `max_nesting_level` setting (#243)
  - Added minor performance optimizations to `Cursor`
 
 ### Changed

diff --git a/src/DocParser.php b/src/DocParser.php
@@ -32,13 +32,19 @@ class DocParser
      */
     private $inlineParserEngine;
 
+    /**
+     * @var int|double
+     */
+    private $maxNestingLevel;
+
     /**
      * @param Environment $environment
      */
     public function __construct(Environment $environment)
     {
         $this->environment = $environment;
         $this->inlineParserEngine = new InlineParserEngine($environment);
+        $this->maxNestingLevel = $environment->getConfig('max_nesting_level', INF);
     }
 
     /**
@@ -197,7 +203,7 @@ private function parseBlocks(ContextInterface $context, Cursor $cursor)
                 }
             }
 
-            if (!$parsed || $context->getContainer()->acceptsLines()) {
+            if (!$parsed || $context->getContainer()->acceptsLines() || $context->getTip()->getDepth() >= $this->maxNestingLevel) {
                 $context->setBlocksParsed(true);
                 break;
             }

diff --git a/src/Environment.php b/src/Environment.php
@@ -485,6 +485,7 @@ public static function createCommonMarkEnvironment()
             'safe'               => false, // deprecated option
             'html_input'         => self::HTML_INPUT_ALLOW,
             'allow_unsafe_links' => true,
+            'max_nesting_level'  => INF,
         ]);
 
         return $environment;

diff --git a/src/Node/Node.php b/src/Node/Node.php
@@ -6,6 +6,11 @@
 
 abstract class Node
 {
+    /**
+     * @var int
+     */
+    protected $depth = 0;
+
     /**
      * @var Node|null
      */
@@ -61,6 +66,7 @@ public function parent()
     protected function setParent(Node $node = null)
     {
         $this->parent = $node;
+        $this->depth = ($node === null) ? 0 : $node->depth + 1;
     }
 
     /**
@@ -129,6 +135,7 @@ public function detach()
         $this->parent = null;
         $this->next = null;
         $this->previous = null;
+        $this->depth = 0;
     }
 
     /**
@@ -225,6 +232,14 @@ public function replaceChildren(array $children)
         return $this;
     }
 
+    /**
+     * @return int
+     */
+    public function getDepth()
+    {
+        return $this->depth;
+    }
+
     /**
      * @return NodeWalker
      */

diff --git a/tests/functional/MaximumNestingLevelTest.php b/tests/functional/MaximumNestingLevelTest.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace League\CommonMark\Tests\functional;
+
+use League\CommonMark\CommonMarkConverter;
+
+class MaximumNestingLevelTest extends \PHPUnit_Framework_TestCase
+{
+    public function testThatWeCanHitTheLimit()
+    {
+        $converter = new CommonMarkConverter(['max_nesting_level' => 2]);
+
+        $markdown = '> > Foo';
+        $expected = '<blockquote>
+<blockquote>
+<p>Foo</p>
+</blockquote>
+</blockquote>
+';
+
+        $this->assertEquals($expected, $converter->convertToHtml($markdown));
+    }
+
+    public function testThatWeCannotExceedTheLimit()
+    {
+        $converter = new CommonMarkConverter(['max_nesting_level' => 2]);
+
+        $markdown = '> > > > > > Foo';
+        $expected = '<blockquote>
+<blockquote>
+<p>&gt; &gt; &gt; &gt; Foo</p>
+</blockquote>
+</blockquote>
+';
+
+        $this->assertEquals($expected, $converter->convertToHtml($markdown));
+    }
+}