test: centralize native header function mocks

Author: datamweb

tests/_support/Mock/MockNativeHeaders.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Debug;
+
+use CodeIgniter\Test\Utilities\NativeHeadersStack;
+
+/**
+ * Mock implementation of the native PHP `headers_sent()` function.
+ *
+ * Instead of checking the actual PHP output buffer, this function
+ * checks the static property in NativeHeadersStack.
+ *
+ * @return bool True if headers are considered sent, false otherwise.
+ */
+function headers_sent(): bool
+{
+    return NativeHeadersStack::headersSent();
+}
+
+/**
+ * Mock implementation of the native PHP `headers_list()` function.
+ *
+ * Retrieves the array of headers stored in the NativeHeadersStack class
+ * rather than the actual headers sent by the server.
+ *
+ * @return array The list of simulated headers.
+ */
+function headers_list(): array
+{
+    return NativeHeadersStack::listHeaders();
+}