Add expression download to return a ressource from a path or url

src/ExpressionLanguage/Download.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kiboko\Component\Satellite\ExpressionLanguage;
+
+use PhpSpec\Locator\Resource;
+use Symfony\Component\ExpressionLanguage\ExpressionFunction;
+
+final class Download extends ExpressionFunction
+{
+    public function __construct(string $name)
+    {
+        parent::__construct(
+            $name,
+            function (string $value): string {
+                $pattern = <<<'PHP'
+                    (function () use ($input) {
+                        $resource = fopen($value, 'r');
+                        if ($resource === false) {
+                            throw new \RuntimeException('Could not open file.');
+                        }
+                        if(!is_readable($resource)) {
+                            throw new \RuntimeException('Could not read the file.');
+                        }
+                        return $ressource;
+                    })()
+                    PHP;
+
+                return sprintf($pattern, $value);
+            },
+            function (string $value) {
+                $resource = fopen($value, 'r');
+                if ($resource === false) {
+                    throw new \RuntimeException('Could not open file.');
+                }
+                return $resource;
+            },
+        );
+    }
+}