Add an assertSelectorCount() assertion.

This assertion validates the number of occurrences of a particular selector within a document. Refs #3.

Author: stevegrunwell

src/MarkupAssertionsTrait.php

@@ -42,6 +42,21 @@ public function assertNotContainsSelector($selector, $output = '', $message = ''
         $this->assertEquals(0, count($results), $message);
     }
 
+    /**
+     * Assert the number of times an element matching the given selector is found.
+     *
+     * @param int    $count    The number of matching elements expected.
+     * @param string $selector A query selector for the element to find.
+     * @param string $output   The markup to run the assertion against.
+     * @param string $message  A message to display if the assertion fails.
+     */
+    public function assertSelectorCount($count, $selector, $output = '', $message = '')
+    {
+        $results = $this->executeDomQuery($output, $selector);
+
+        $this->assertCount($count, $results, $message);
+    }
+
     /**
      * Assert that an element with the given attributes exists in the given markup.
      *

tests/MarkupAssertionsTraitTest.php

@@ -51,6 +51,15 @@ public function testAssertNotContainsSelector($selector)
         );
     }
 
+    public function testAssertSelectorCount()
+    {
+        $this->testcase->assertSelectorCount(
+            3,
+            'li',
+            '<ul><li>1</li><li>2</li><li>3</li></ul>'
+        );
+    }
+
     public function testAssertHasElementWithAttributes()
     {
         $this->testcase->assertHasElementWithAttributes(