Merge pull request #5 from stevegrunwell/feature/assert-selector-count

Introduce assertSelectorCount() assertion

Author: stevegrunwell

README.md

@@ -89,6 +89,7 @@ These are the assertions made available to PHPUnit via the `MarkupAssertionsTrai
 
 * [`assertContainsSelector()`](#assertcontainsselector)
 * [`assertNotContainsSelector()`](#assertnotcontainsselector)
+* [`assertSelectorCount()`](#assertselectorcount)
 * [`assertHasElementWithAttributes()`](#asserthaselementwithattributes)
 * [`assertNotHasElementWithAttributes()`](#assertnothaselementwithattributes)
 
@@ -131,6 +132,34 @@ This method is the inverse of [`assertContainsSelector()`](#assertcontainsselect
     <dd>A message to display if the assertion fails.</dd>
 </dl>
 
+### assertSelectorCount()
+
+Assert the number of times an element matching the given selector is found.
+
+<dl>
+    <dt>(int) $count</dt>
+    <dd>The number of matching elements expected.</dd>
+    <dt>(string) $selector</dt>
+    <dd>A query selector for the element to find.</dd>
+    <dt>(string) $output</dt>
+    <dd>The markup to run the assertion against.</dd>
+    <dt>(string) $message</dt>
+    <dd>A message to display if the assertion fails.</dd>
+</dl>
+
+#### Example
+
+```php
+public function testPostList()
+{
+    factory(Post::class, 10)->create();
+
+    $response = $this->get('/posts');
+
+    $this->assertSelectorCount(10, 'li.post-item', $response->getBody());
+}
+```
+
 ### assertHasElementWithAttributes()
 
 Assert that an element with the given attributes exists in the given markup.

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(