REFACTOR: move polyfills (array_key_last and array_key_first)

tests/Acceptance/bootstrap.php

 <?php
 // Here you can initialize variables that will be available to your tests, e.g. the app's bootstrap.php
-
-// Polyfill for array_key_first() function added in PHP 7.3.
-if (!function_exists('array_key_first')) {
-    function array_key_first(array $array)
-    {
-        if ($array === []) {
-            return null;
-        }
-        foreach ($array as $key => $_) {
-            return $key;
-        }
-    }
-}
-
-// Polyfill for array_key_last() function added in PHP 7.3.
-if (!function_exists('array_key_last')) {
-    function array_key_last(array $array)
-    {
-        if ($array === []) {
-            return null;
-        }
-        return array_key_first(array_slice($array, -1));
-    }
-}

tests/bootstrap.php

@@ -6,3 +6,27 @@
  * unit tests in this file.
  */
 require dirname(__DIR__) . '/config/bootstrap.php';
+
+// Polyfill for array_key_first() function added in PHP 7.3.
+if (!function_exists('array_key_first')) {
+    function array_key_first(array $array)
+    {
+        if ($array === []) {
+            return null;
+        }
+        foreach ($array as $key => $_) {
+            return $key;
+        }
+    }
+}
+
+// Polyfill for array_key_last() function added in PHP 7.3.
+if (!function_exists('array_key_last')) {
+    function array_key_last(array $array)
+    {
+        if ($array === []) {
+            return null;
+        }
+        return array_key_first(array_slice($array, -1));
+    }
+}