diff --git a/spec/cron_spec.lua b/spec/cron_spec.lua
index 9b7287e..ff1a7e1 100644
--- a/spec/cron_spec.lua
+++ b/spec/cron_spec.lua
@@ -109,6 +109,37 @@ describe( 'cron', function()
     end)
   end)
 
+  describe('.doFor', function()
+    it('Throws errors if time is not a positive number, or callback is not function', function()
+      assert_error(function() cron.every('error', count) end)
+      assert_error(function() cron.every(2, 'error') end)
+      assert_error(function() cron.every(-2, count) end)
+      assert_error(function() cron.every(-2, {}) end)
+      assert_not_error(function() cron.every(2, count) end)
+      assert_not_error(function() cron.every(2, countable) end)
+    end)
+
+    it('Executes actions on every update until the timer expires', function()
+      cron.doFor(5, count)
+      assert_equal(counter, 0)
+      cron.update(1)
+      assert_equal(counter, 1)
+      cron.update(3)
+      assert_equal(counter, 2)
+      cron.update(3)
+      assert_equal(counter, 3)
+      cron.update(1)
+      assert_equal(counter, 3)
+    end)
+
+    it('Respects parameters', function()
+      cron.doFor(4, count, 2)
+      cron.update(1)
+      cron.update(1)
+      assert_equal(counter, 4)
+    end)
+  end)
+
   describe('.cancel', function()
     it('Cancels timed entries', function()
       local id = cron.after(1, count)