From 63e3c95faead959b08ef89b005d597732738239a Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Wed, 9 Sep 2026 19:54:24 +0930
Subject: [PATCH] Fix custom filter rate-limit counter never expiring

---
 .../Controllers/CustomFilterController.php    | 14 ++--
 .../Feature/Api/CustomFilterRateLimitTest.php | 79 +++++++++++++++++++
 2 files changed, 87 insertions(+), 6 deletions(-)
 create mode 100644 tests/Feature/Api/CustomFilterRateLimitTest.php

diff --git a/app/Http/Controllers/CustomFilterController.php b/app/Http/Controllers/CustomFilterController.php
index f6ad93352..e42344638 100644
--- a/app/Http/Controllers/CustomFilterController.php
+++ b/app/Http/Controllers/CustomFilterController.php
@@ -180,10 +180,11 @@ class CustomFilterController extends Controller
                 }
             }
 
+            // Create the counter with a 1h TTL only on first write, then
+            // increment. increment() alone would create a TTL-less key, so the
+            // "per hour" window must be established by the add() before it.
+            Cache::add($rateKey, 0, 3600);
             Cache::increment($rateKey);
-            if (! Cache::has($rateKey)) {
-                Cache::put($rateKey, 1, 3600);
-            }
 
             Cache::forget("filters:v3:{$profile_id}");
 
@@ -445,10 +446,11 @@ class CustomFilterController extends Controller
                 }
             }
 
+            // Create the counter with a 1h TTL only on first write, then
+            // increment. increment() alone would create a TTL-less key, so the
+            // "per hour" window must be established by the add() before it.
+            Cache::add($rateKey, 0, 3600);
             Cache::increment($rateKey);
-            if (! Cache::has($rateKey)) {
-                Cache::put($rateKey, 1, 3600);
-            }
 
             Cache::forget("filters:v3:{$pid}");
 
diff --git a/tests/Feature/Api/CustomFilterRateLimitTest.php b/tests/Feature/Api/CustomFilterRateLimitTest.php
new file mode 100644
index 000000000..b13d445d5
--- /dev/null
+++ b/tests/Feature/Api/CustomFilterRateLimitTest.php
@@ -0,0 +1,79 @@
+<?php
+
+use App\Models\CustomFilter;
+use App\Models\User;
+use Illuminate\Foundation\Testing\LazilyRefreshDatabase;
+use Illuminate\Support\Facades\Cache;
+use Laravel\Passport\Passport;
+
+uses(LazilyRefreshDatabase::class);
+
+/*
+|--------------------------------------------------------------------------
+| Custom filter create rate limit TTL
+|--------------------------------------------------------------------------
+|
+| The per-hour create limit counter must carry a 1h TTL so it resets after the
+| window. Previously Cache::increment created the key with no TTL, so once the
+| cap was hit the 429 persisted indefinitely (until external cache eviction).
+|
+*/
+
+/**
+ * Reset the memoized limit statics so per-test config overrides take effect.
+ */
+function resetFilterLimitStatics(): void
+{
+    foreach (['maxCreatePerHour', 'maxUpdatesPerHour', 'maxFiltersPerUser'] as $prop) {
+        $ref = new ReflectionProperty(CustomFilter::class, $prop);
+        $ref->setAccessible(true);
+        $ref->setValue(null, null);
+    }
+}
+
+function createFilter(string $title, string $keyword)
+{
+    return test()->postJson('/api/v2/filters', [
+        'title' => $title,
+        'context' => ['home'],
+        'filter_action' => 'warn',
+        'keywords_attributes' => [
+            ['keyword' => $keyword, 'whole_word' => true],
+        ],
+    ]);
+}
+
+beforeEach(function () {
+    Cache::flush();
+    config(['instance.custom_filters.max_create_per_hour' => 2]);
+    config(['instance.custom_filters.max_filters_per_user' => 100]);
+    resetFilterLimitStatics();
+});
+
+it('resets the create rate limit after the 1 hour window', function () {
+    $user = User::factory()->create();
+    $user->refresh();
+    Passport::actingAs($user, ['read', 'write']);
+
+    // Two creates within the cap succeed.
+    createFilter('one', 'alpha')->assertOk();
+    createFilter('two', 'bravo')->assertOk();
+
+    // Third exceeds the cap -> 429.
+    createFilter('three', 'charlie')->assertStatus(429);
+
+    // After the 1h window elapses, the counter must reset and allow writes.
+    $this->travel(3700)->seconds();
+
+    createFilter('four', 'delta')->assertOk();
+});
+
+it('rejects writes once the cap is reached within the window', function () {
+    $user = User::factory()->create();
+    $user->refresh();
+    Passport::actingAs($user, ['read', 'write']);
+
+    createFilter('one', 'alpha')->assertOk();
+    createFilter('two', 'bravo')->assertOk();
+    createFilter('three', 'charlie')->assertStatus(429);
+});