Reinforce logical linings of a Lock

app/models/lock.rb

@@ -1,37 +1,40 @@
 class Lock < ApplicationRecord
   scope :expired, -> { where "expiration <= ?", Time.now }
+  scope :active, -> { expired.invert_where }
 
   class << self
-    def acquire(key, limit: 1, duration: nil, &block)
+    def acquire(key, limit: 1, duration: nil)
       lock = nil
       transaction do
-        lock = find_by(key:) || create!(key:, expiration: duration&.from_now)
-        if lock.capacity == limit
+        lock = active.find_by(key:) || create!(key:, expiration: duration&.from_now)
+
+        if lock.capacity >= limit
           return false
+        else
+          lock.acquire
         end
       end
 
-      lock.acquire
-
       begin
-        yield block
+        yield
+        true
       ensure
         lock.release
       end
     end
   end
 
   def acquire(capacity = 1)
-    increment!(:capacity, capacity)
+    increment! :capacity, capacity
   end
 
   def release(quantity = 1)
     transaction do
       reload
-      if capacity == 1
+      if capacity <= 1
         destroy!
       else
-        decrement!(:capacity, quantity)
+        decrement! :capacity, quantity
       end
     end
   end