Added nil param tests

test/timecop_test.rb

@@ -289,8 +289,12 @@ def test_scaling_returns_now_if_no_block_given
     t = Time.local(2008, 10, 10, 10, 10, 10)
     assert_times_effectively_equal t, Timecop.scale(4, t)
   end
+
+  def test_scaling_returns_now_if_nil_supplied
+    assert_times_effectively_equal Time.now, Timecop.scale(nil)
+  end
 
-  def test_scale_raises_when_empty_string_supplied
+  def test_scaling_raises_when_empty_string_supplied
     err = assert_raises(TypeError) do
       Timecop.scale("")
     end
@@ -401,6 +405,10 @@ def test_return_temporarily_returns_to_current_time_in_given_block
     end
     assert_times_effectively_equal(time_after_travel, Time.now)
   end
+
+  def test_travel_returns_now_if_nil_supplied
+    assert_times_effectively_equal Time.now, Timecop.travel(nil)
+  end
 
   def test_travel_time_with_block_returns_the_value_of_the_block
     t_future = Time.local(2030, 10, 10, 10, 10, 10)
@@ -442,6 +450,10 @@ def test_freeze_without_params
       end
     end
   end
+
+   def test_freeze_returns_now_if_nil_supplied
+    assert_times_effectively_equal Time.now, Timecop.freeze(nil)
+  end
 
   def test_freeze_raises_when_empty_string_supplied
     err = assert_raises(ArgumentError) do