feat: adds array_is_list polyfill

Author: JasonTheAdams

composer.json

@@ -34,7 +34,10 @@
     "autoload": {
         "psr-4": {
             "WordPress\\AiClient\\": "src/"
-        }
+        },
+        "files": [
+            "src/polyfills.php"
+        ]
     },
     "autoload-dev": {
         "psr-4": {

src/polyfills.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * Polyfills for PHP functions that may not be available in older versions.
+ *
+ * @since n.e.x.t
+ */
+
+declare(strict_types=1);
+
+if (!function_exists('array_is_list')) {
+    /**
+     * Checks whether a given array is a list.
+     *
+     * An array is considered a list if its keys consist of consecutive numbers from 0 to count($array)-1.
+     *
+     * @param array<mixed> $array The array to check.
+     * @return bool True if the array is a list, false otherwise.
+     *
+     * @since n.e.x.t
+     */
+    function array_is_list(array $array): bool
+    {
+        if ($array === []) {
+            return true;
+        }
+
+        $expectedKey = 0;
+        foreach (array_keys($array) as $key) {
+            if ($key !== $expectedKey) {
+                return false;
+            }
+            $expectedKey++;
+        }
+
+        return true;
+    }
+}