Preserve IP exclusions on their first save

src/Settings/Blocks/Fields/IpList.php

@@ -15,12 +15,8 @@ class IpList extends Field
     public function getValueSanitizer(): callable
     {
         return function ($value) {
-            $ips = [];
-
-            if (! is_array($value)) {
-                $ips = explode("\n", $value);
-            }
-
+            $ips = is_array($value) ? $value : (is_string($value) ? explode("\n", $value) : []);
+            $ips = array_filter($ips, 'is_string');
             $ips = array_map('trim', $ips);
             $ips = array_filter($ips, function ($ip) {
                 return filter_var($ip, FILTER_VALIDATE_IP) !== false;

tests/Browser/phpRegression.spec.ts

@@ -0,0 +1,16 @@
+import { test, expect } from '@playwright/test';
+import { execFileSync } from 'node:child_process';
+import { readdirSync } from 'node:fs';
+import { basename, resolve } from 'node:path';
+
+// Each script uses its own temporary options table, so these checks can run
+// alongside browser tests without changing their WordPress settings.
+for (const file of readdirSync(resolve('tests/Regression')).filter(name => name.endsWith('.php'))) {
+  test(`WordPress regression: ${file}`, () => {
+    const output = execFileSync(resolve('node_modules/.bin/wp-env'), [
+      'run', 'cli', 'wp', 'eval-file',
+      `wp-content/plugins/${basename(process.cwd())}/tests/Regression/${file}`,
+    ], { encoding: 'utf8', timeout: 45000 });
+    expect(output).toContain('Regression checks passed');
+  });
+}

tests/Regression/ip-sanitization.php

@@ -0,0 +1,26 @@
+<?php
+
+require __DIR__ . '/../Support/isolated-options.php';
+
+sa_with_isolated_options(static function () {
+    $key = SimpleAnalytics\SettingName::EXCLUDED_IP_ADDRESSES;
+    $field = new SimpleAnalytics\Settings\Blocks\Fields\IpList($key, 'IP addresses');
+    $sanitize = $field->getValueSanitizer();
+    register_setting('simpleanalytics-ignore-rules', $key, [
+        'type' => $field->getValueType(),
+        'sanitize_callback' => $sanitize,
+    ]);
+
+    delete_option($key);
+    update_option($key, "203.0.113.10\n2001:db8::1");
+    $expected = ['203.0.113.10', '2001:db8::1'];
+    sa_assert(get_option($key) === $expected, 'First save must retain addresses after double sanitization.');
+    sa_assert($sanitize($expected) === $expected, 'Sanitizing an array must preserve valid addresses.');
+    sa_assert($sanitize($sanitize($expected)) === $expected, 'Sanitization must be idempotent.');
+    sa_assert($sanitize([' 203.0.113.10 ', '203.0.113.10', 'invalid', [], null, new stdClass()]) === ['203.0.113.10'], 'Reject malformed items and remove duplicates.');
+    foreach ([null, false, 123, new stdClass(), ''] as $invalid) {
+        sa_assert($sanitize($invalid) === [], 'Malformed or empty input must produce an empty list.');
+    }
+    update_option($key, "203.0.113.20\r\ninvalid\r\n203.0.113.20");
+    sa_assert(get_option($key) === ['203.0.113.20'], 'Existing options must still accept textarea updates.');
+});

tests/Support/isolated-options.php

@@ -0,0 +1,39 @@
+<?php
+
+/** Run only through wp eval-file against the local wp-env installation. */
+function sa_assert($condition, string $message): void
+{
+    if (! $condition) throw new RuntimeException($message);
+}
+
+function sa_with_isolated_options(callable $test): void
+{
+    global $wpdb, $wp_object_cache;
+
+    sa_assert(! wp_using_ext_object_cache(), 'Regression tests require the default object cache.');
+    $originalTable = $wpdb->options;
+    $originalCache = $wp_object_cache;
+    $table = 'sa_regression_options';
+    $guard = static function ($sql) use ($table) {
+        if (! preg_match('/^\s*(SELECT|SHOW|DESCRIBE|EXPLAIN)\b/i', $sql) && strpos($sql, $table) === false) {
+            throw new RuntimeException('Refusing a write outside the temporary test table.');
+        }
+        return $sql;
+    };
+    add_filter('query', $guard, 9999);
+
+    try {
+        sa_assert($wpdb->query("CREATE TEMPORARY TABLE $table LIKE $originalTable") !== false, $wpdb->last_error);
+        sa_assert($wpdb->query("INSERT INTO $table SELECT * FROM $originalTable") !== false, $wpdb->last_error);
+        $wpdb->options = $table;
+        $wp_object_cache = new WP_Object_Cache();
+        wp_cache_switch_to_blog(get_current_blog_id());
+        $test();
+        echo "Regression checks passed\n";
+    } finally {
+        $wpdb->options = $originalTable;
+        $wp_object_cache = $originalCache;
+        remove_filter('query', $guard, 9999);
+    }
+    // The database connection automatically drops the temporary table on exit.
+}