Merge pull request #22 from FabianKoestring/patch-async

Added optional attribute 'async'

Author: weierophinney

src/Helper/HeadScript.php

@@ -87,6 +87,7 @@ class HeadScript extends Placeholder\Container\AbstractStandalone
         'charset',
         'crossorigin',
         'defer',
+        'async',
         'language',
         'src',
     ];
@@ -393,6 +394,9 @@ public function itemToString($item, $indent, $escapeStart, $escapeEnd)
                 if ('defer' == $key) {
                     $value = 'defer';
                 }
+                if ('async' == $key) {
+                    $value = 'async';
+                }
                 $attrString .= sprintf(' %s="%s"', $key, ($this->autoEscape) ? $this->escape($value) : $value);
             }
         }

test/Helper/HeadScriptTest.php

@@ -491,4 +491,15 @@ public function testOmitsTypeAttributeIfEmptyValueAndHtml5Doctype()
         $test = $this->helper->__invoke()->toString();
         $this->assertNotContains('type', $test);
     }
+
+    public function testSupportsAsyncAttribute()
+    {
+        $this->helper->__invoke()->appendScript(
+            '// some script' . PHP_EOL,
+            'text/javascript',
+            ['async' => true]
+        );
+        $test = $this->helper->__invoke()->toString();
+        $this->assertContains('async="', $test);
+    }
 }