Add protection against double inclusion of global function declarations

generator/GlobalFunctionFile.php

@@ -13,7 +13,7 @@ class GlobalFunctionFile extends FactoryFile
 
     public function __construct($file)
     {
-        parent::__construct($file, '');
+        parent::__construct($file, '    ');
         $this->functions = '';
     }
 
@@ -26,7 +26,8 @@ public function build()
     {
         $this->addFileHeader();
         $this->addPart('functions_imports');
-        $this->addPart('assertThat');
+        $this->addPart('functions_header');
         $this->addCode($this->functions);
+        $this->addPart('functions_footer');
     }
 }

generator/parts/functions_footer.txt

@@ -0,0 +1 @@
+}

generator/parts/functions_header.txt

@@ -0,0 +1,23 @@
+
+if (!function_exists('assertThat')) {
+    /**
+     * Make an assertion and throw {@link Hamcrest_AssertionError} if it fails.
+     *
+     * Example:
+     * <pre>
+     * //With an identifier
+     * assertThat("assertion identifier", $apple->flavour(), equalTo("tasty"));
+     * //Without an identifier
+     * assertThat($apple->flavour(), equalTo("tasty"));
+     * //Evaluating a boolean expression
+     * assertThat("some error", $a > $b);
+     * </pre>
+     */
+    function assertThat()
+    {
+        $args = func_get_args();
+        call_user_func_array(
+            array('Hamcrest\MatcherAssert', 'assertThat'),
+            $args
+        );
+    }