Add decrement method to the rate limiter class (#51102)

src/Illuminate/Cache/RateLimiter.php

@@ -143,6 +143,19 @@ public function increment($key, $decaySeconds = 60, $amount = 1)
         return $hits;
     }
 
+    /**
+     * Decrement the counter for a given key for a given decay time by a given amount.
+     *
+     * @param  string  $key
+     * @param  int  $decaySeconds
+     * @param  int  $amount
+     * @return int
+     */
+    public function decrement($key, $decaySeconds = 60, $amount = 1)
+    {
+        return $this->increment($key, $decaySeconds, $amount * -1);
+    }
+
     /**
      * Get the number of attempts for the given key.
      *

src/Illuminate/Support/Facades/RateLimiter.php

@@ -9,6 +9,7 @@
  * @method static bool tooManyAttempts(string $key, int $maxAttempts)
  * @method static int hit(string $key, int $decaySeconds = 60)
  * @method static int increment(string $key, int $decaySeconds = 60, int $amount = 1)
+ * @method static int decrement(string $key, int $decaySeconds = 60, int $amount = 1)
  * @method static mixed attempts(string $key)
  * @method static mixed resetAttempts(string $key)
  * @method static int remaining(string $key, int $maxAttempts)

tests/Cache/CacheRateLimiterTest.php

@@ -47,6 +47,17 @@ public function testIncrementProperlyIncrementsAttemptCount()
         $rateLimiter->increment('key', 1, 5);
     }
 
+    public function testDecrementProperlyDecrementsAttemptCount()
+    {
+        $cache = m::mock(Cache::class);
+        $cache->shouldReceive('add')->once()->with('key:timer', m::type('int'), 1)->andReturn(true);
+        $cache->shouldReceive('add')->once()->with('key', 0, 1)->andReturn(true);
+        $cache->shouldReceive('increment')->once()->with('key', -5)->andReturn(-5);
+        $rateLimiter = new RateLimiter($cache);
+
+        $rateLimiter->decrement('key', 1, 5);
+    }
+
     public function testHitHasNoMemoryLeak()
     {
         $cache = m::mock(Cache::class);