Fix '~=' operator

src/Fenom/Template.php

@@ -724,6 +724,10 @@ class Template extends Render
                     break;
                 }
             } elseif ($tokens->is('~')) { // string concatenation operator: 'asd' ~ $var
+                if($tokens->isNext('=')) { // ~=
+                    $exp[] = ".=";
+                    $tokens->next()->next();
+                } else {
                     $concat = array(array_pop($exp));
                     while ($tokens->is('~')) {
                         $tokens->next();
@@ -734,6 +738,7 @@ class Template extends Render
                         }
                     }
                     $exp[] = "(" . implode(".", $concat) . ")";
+                }
             } else {
                 break;
             }

tests/cases/Fenom/TemplateTest.php

@@ -1170,6 +1170,7 @@ class TemplateTest extends TestCase
             array('{"string" ~ ++$one ~ "end"}', "string2end"),
             array('{"string" ~ "one" ~ "end"}', "stringoneend"),
             array('{"string" ~ 1 ~ "end"}', "string1end"),
+            array('{$one ~= "string"} is {$one}', "1string is 1string"),
         );
     }
 
@@ -1536,6 +1537,7 @@ class TemplateTest extends TestCase
 
     /**
      * @dataProvider providerConcat
+     * @group testConcat
      */
     public function testConcat($code, $result)
     {