implement token bucket rate limiting

test/unit/token_bucket_test.rb

@@ -0,0 +1,45 @@
+require 'test_helper'
+
+class TokenBucketTest < ActiveSupport::TestCase
+  context "#add!" do
+    setup do
+      @user = FactoryGirl.create(:user)
+      TokenBucket.create(user_id: @user.id, last_touched_at: 1.minute.ago, token_count: 0)
+    end
+
+    should "work" do
+      @user.token_bucket.add!
+      assert_operator(@user.token_bucket.token_count, :>, 0)
+      @user.reload
+      assert_operator(@user.token_bucket.token_count, :>, 0)
+    end
+  end
+
+  context "#consume!" do
+    setup do
+      @user = FactoryGirl.create(:user)
+      TokenBucket.create(user_id: @user.id, last_touched_at: 1.minute.ago, token_count: 1)
+    end
+
+    should "work" do
+      @user.token_bucket.consume!
+      assert_operator(@user.token_bucket.token_count, :<, 1)
+      @user.reload     
+      assert_operator(@user.token_bucket.token_count, :<, 1)
+    end
+  end
+
+  context "#throttled?" do
+    setup do
+      @user = FactoryGirl.create(:user)
+      TokenBucket.create(user_id: @user.id, last_touched_at: 1.minute.ago, token_count: 0)
+    end
+
+    should "work" do
+      assert(!@user.token_bucket.throttled?)
+      assert_operator(@user.token_bucket.token_count, :<, 60)
+      @user.reload
+      assert_operator(@user.token_bucket.token_count, :<, 60)
+    end
+  end
+end