Add conditional return type for wp_unique_id (#231)

Author: IanDelMar

functionMap.php

@@ -84,6 +84,7 @@
     'wp_slash' => ['T', '@phpstan-template' => 'T', 'value' => 'T'],
     'wp_tag_cloud' => ["(\$args is array{format: 'array'} ? array<int, string>|void : (\$args is array{echo: false|0} ? string|void : void))"],
     'wp_trigger_error' => [null, 'function_name' => 'callable-string', 'error_level' => '\E_USER_ERROR|\E_USER_WARNING|\E_USER_NOTICE|\E_USER_DEPRECATED'],
+    'wp_unique_id' => ['($prefix is empty ? numeric-string : ($prefix is numeric ? numeric-string : string))'],
     'wp_unschedule_event' => ['($wp_error is false ? bool : true|\WP_Error)', 'args' => $cronArgsType],
     'wp_unslash' => ['T', '@phpstan-template' => 'T', 'value' => 'T'],
     'wp_widget_rss_form' => ['void', 'args' => $wpWidgetRssFormArgsType, 'inputs' => $wpWidgetRssFormInputsType],

tests/TypeInferenceTest.php

@@ -66,6 +66,7 @@ public function dataFileAsserts(): iterable
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_tag_cloud.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_theme.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_translations.php');
+        yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_unique_id.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_widget_factory.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wpdb.php');
     }

tests/data/wp_unique_id.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use function wp_unique_id;
+use function PHPStan\Testing\assertType;
+
+/** @var numeric-string $numericString */
+$numericString = $_GET['numericString'];
+
+assertType('numeric-string', wp_unique_id());
+assertType('numeric-string', wp_unique_id(''));
+assertType('numeric-string', wp_unique_id('1'));
+assertType('numeric-string', wp_unique_id($numericString));
+
+assertType('string', wp_unique_id('string'));
+assertType('string', wp_unique_id($_GET['string']));

wordpress-stubs.php

@@ -110473,6 +110473,7 @@ function wp_is_uuid($uuid, $version = \null)
      *
      * @param string $prefix Prefix for the returned ID.
      * @return string Unique ID.
+     * @phpstan-return ($prefix is empty ? numeric-string : ($prefix is numeric ? numeric-string : string))
      */
     function wp_unique_id($prefix = '')
     {