diff --git a/spec/models/rate_spec.rb b/spec/models/rate_spec.rb
deleted file mode 100644
index d068ca9..0000000
--- a/spec/models/rate_spec.rb
+++ /dev/null
@@ -1,298 +0,0 @@
-require File.dirname(__FILE__) + '/../spec_helper'
-
-module RateSpecHelper
-  def rate_valid_attributes
-    { 
-      :user => mock_model(User),
-      :project => mock_model(Project),
-      :date_in_effect => Date.new(Date.today.year, 1, 1),
-      :amount => 100.50
-    }
-  end
-end
-
-describe Rate do
-  include RateSpecHelper
-  
-  it 'should be valid with a user' do
-    rate = Rate.new(rate_valid_attributes)
-    rate.should be_valid
-  end
-
-  it 'should be valid with a project' do
-    rate = Rate.new(rate_valid_attributes)
-    rate.should be_valid
-  end
-  
-  it 'should be valid without a project' do
-    rate = Rate.new(rate_valid_attributes.except(:project))
-    rate.should be_valid
-  end
-
-  it 'should not be valid without a user' do
-    rate = Rate.new(rate_valid_attributes.except(:user))
-    rate.should_not be_valid
-    rate.should have(1).error_on(:user_id)
-  end
-  
-  it 'should not be valid without a date_in_effect' do
-    rate = Rate.new(rate_valid_attributes.except(:date_in_effect))
-    rate.should_not be_valid
-    rate.should have(1).error_on(:date_in_effect)
-  end
-end
-
-describe Rate, 'associations' do
-  it 'should have many time entries' do
-    Rate.should have_association(:time_entries, :has_many)
-  end
-
-  it 'should belong to a single user' do
-    Rate.should have_association(:user, :belongs_to)
-  end
-
-  it 'should belong to a single project' do
-    Rate.should have_association(:project, :belongs_to)
-  end
-
-end
-
-describe Rate, 'locked?' do
-  it 'should be true if a Time Entry is associated' do
-    rate = Rate.new
-    rate.time_entries << mock_model(TimeEntry)
-    rate.locked?.should be_true
-  end
-  
-  it 'should be false if no Time Entries are associated' do
-    rate = Rate.new
-    rate.locked?.should be_false
-  end
-  
-end
-
-describe Rate, 'locked?' do
-  it 'should be false if a Time Entry is associated' do
-    rate = Rate.new
-    rate.time_entries << mock_model(TimeEntry)
-    rate.unlocked?.should be_false
-  end
-  
-  it 'should be true if no Time Entries are associated' do
-    rate = Rate.new
-    rate.unlocked?.should be_true
-  end
-  
-end
-
-describe Rate, 'save' do
-  include RateSpecHelper
-
-  it 'should save if a Rate is unlocked' do
-    rate = Rate.new(rate_valid_attributes)
-    rate.stub!(:locked?).and_return(false)
-    rate.save.should eql(true)
-  end
-
-  it 'should not save if a Rate is locked' do
-    rate = Rate.new(rate_valid_attributes)
-    rate.stub!(:locked?).and_return(true)
-    rate.save.should eql(false)
-  end
-end
-
-describe Rate, 'destroy' do
-  include RateSpecHelper
-
-  it 'should destroy the Rate if it is unlocked' do
-    rate = Rate.create(rate_valid_attributes)
-    rate.stub!(:locked?).and_return(false)
-    proc {
-      rate.destroy
-    }.should change(Rate, :count).by(-1)
-
-  end
-
-  it 'should not destroy the Rate if it is locked' do
-    rate = Rate.create(rate_valid_attributes)
-    rate.stub!(:locked?).and_return(true)
-    proc {
-      rate.destroy
-    }.should_not change(Rate, :count)
-  end
-end
-
-describe Rate, 'for' do
-  before(:each) do
-    @user = mock_model(User)
-    @project = mock_model(Project)
-    @date = '2009-01-01'
-    @rate = mock_model(Rate, :amount => 50.50)
-  end
-    
-  describe 'parameters' do
-    it 'should be passed user' do
-      lambda {Rate.for}.should raise_error(ArgumentError)
-    end
-
-    it 'can be passed an optional project' do
-      lambda {Rate.for(@user)}.should_not raise_error(ArgumentError)
-      lambda {Rate.for(@user, @project)}.should_not raise_error(ArgumentError)
-    end
-  
-    it 'can be passed an optional date string' do
-      lambda {Rate.for(@user)}.should_not raise_error(ArgumentError)
-      lambda {Rate.for(@user, nil, @date)}.should_not raise_error(ArgumentError)
-    end
-    
-  end
-
-  describe 'returns' do
-    it 'a Rate object when there is a rate' do
-      Rate.stub!(:for_user_project_and_date).with(@user, @project, @date).and_return(@rate)
-      Rate.for(@user, @project, @date).should eql(@rate)
-    end
-
-    it 'a nil when there is no rate' do
-      Rate.for(@user, @project, @date).should be_nil
-    end
-  end
-  
-  describe 'with a user, project, and date' do
-    it 'should find the rate for a user on the project before the date' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, @date).and_return(@rate)
-      Rate.for(@user, @project, @date)
-    end
-
-    it 'should return the most recent rate found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, @date).and_return(@rate)
-      Rate.for(@user, @project, @date).should eql(@rate)
-    end
-    
-    it 'should check for a default rate if no rate is found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, @date).and_return(nil)
-      Rate.should_receive(:default_for_user_and_date).with(@user, @date).and_return(@rate)
-      Rate.for(@user, @project, @date).should eql(@rate)
-    end
-    
-    it 'should return nil if no set or default rate is found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, @date).and_return(nil)
-      Rate.should_receive(:default_for_user_and_date).with(@user, @date).and_return(nil)
-      Rate.for(@user, @project, @date).should be_nil
-    end
-  end
-
-  describe 'with a user and project' do
-    it 'should find the rate for a user on the project before today' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, Date.today.to_s).and_return(@rate)
-      Rate.for(@user, @project)
-    end
-
-    it 'should return the most recent rate found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, Date.today.to_s).and_return(@rate)
-      Rate.for(@user, @project).should eql(@rate)
-    end
-
-    it 'should return nil if no set or default rate is found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, @project, Date.today.to_s).and_return(nil)
-      Rate.should_receive(:default_for_user_and_date).with(@user, Date.today.to_s).and_return(nil)
-      Rate.for(@user, @project).should be_nil
-    end
-  end
-
-  describe 'with a user' do
-    it 'should find the rate without a project for a user on the project before today' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, nil, Date.today.to_s).and_return(@rate)
-      Rate.for(@user)
-    end
-
-    it 'should return the most recent rate found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, nil, Date.today.to_s).and_return(@rate)
-      Rate.for(@user).should eql(@rate)
-    end
-
-    it 'should return nil if no set or default rate is found' do
-      Rate.should_receive(:for_user_project_and_date).with(@user, nil, Date.today.to_s).and_return(nil)
-      Rate.for(@user).should be_nil
-    end
-  end
-  
-  it 'with an invalid user should raise an InvalidParameterException' do
-    object = mock('random_object_with_id_attribute')
-    Rate.should_not_receive(:for_user_project_and_date)
-    lambda {
-      Rate.for(object)
-    }.should raise_error(Rate::InvalidParameterException, "user must be a Principal instance")
-  end
-  
-  it 'with an invalid project should raise an InvalidParameterException' do
-    object = mock('random_object_with_id_attribute')
-    Rate.should_not_receive(:for_user_project_and_date)
-    lambda {
-      Rate.for(@user, object)
-    }.should raise_error(Rate::InvalidParameterException, "project must be a Project instance")
-  end
-  
-  it 'with an invalid object for date should raise an InvalidParameterException' do
-    object = mock('random_object_thats_not_a_string')
-    Rate.should_not_receive(:for_user_project_and_date)
-    lambda {
-      Rate.for(@user, @project, object)
-    }.should raise_error(Rate::InvalidParameterException, "date must be a valid Date string (e.g. YYYY-MM-DD)")
-  end
-
-  it 'with an invalid date string should raise an InvalidParameterException' do
-    Rate.should_not_receive(:for_user_project_and_date)
-    lambda {
-      Rate.for(@user, @project, '2000-13-40')
-    }.should raise_error(Rate::InvalidParameterException, "date must be a valid Date string (e.g. YYYY-MM-DD)")
-  end
-
-
-  
-end
-
-describe Rate, 'for_user_project_and_date (private)' do
-  before(:each) do
-    @user = mock_model(User)
-    @project = mock_model(Project)
-    @date = '2009-01-01'
-    @rate = mock_model(Rate, :amount => 50.50)
-  end
-
-  it 'should find the rate for a user on the project before the date' do
-    Rate.should_receive(:find).with(:first, {
-                                      :conditions => ["user_id IN (?) AND project_id IN (?) AND date_in_effect <= ?",
-                                                      @user.id,
-                                                      @project.id,
-                                                      @date
-                                                     ],
-                                      :order => 'date_in_effect DESC'
-                                    }).and_return(@rate)
-
-    Rate.send(:for_user_project_and_date, @user, @project, @date)
-  end
-
-  it 'should return the value of the most recent rate found' do
-    Rate.should_receive(:find).with(:first, {
-                                      :conditions => ["user_id IN (?) AND project_id IN (?) AND date_in_effect <= ?",
-                                                      @user.id,
-                                                      @project.id,
-                                                      @date
-                                                     ],
-                                      :order => 'date_in_effect DESC'
-                                    }).and_return(@rate1)
-    Rate.send(:for_user_project_and_date, @user, @project, @date).should eql(@rate1)
-  end
-  
-  it 'should search rates without a project when +project+ is nil' do
-    Rate.should_receive(:find).with(:first, {
-                                      :conditions => ["user_id IN (?) AND date_in_effect <= ? AND project_id IS NULL",
-                                                      @user.id,
-                                                      @date
-                                                     ],
-                                      :order => 'date_in_effect DESC'
-                                    }).and_return(@rate1)
-    Rate.send(:for_user_project_and_date, @user, nil, @date).should eql(@rate1)
-  end
-end
diff --git a/test/unit/rate_test.rb b/test/unit/rate_test.rb
new file mode 100644
index 0000000..89bce69
--- /dev/null
+++ b/test/unit/rate_test.rb
@@ -0,0 +1,225 @@
+require File.dirname(__FILE__) + '/../test_helper'
+
+class RateTest < ActiveSupport::TestCase
+  def rate_valid_attributes
+    { 
+      :user => User.generate!,
+      :project => Project.generate!,
+      :date_in_effect => Date.new(Date.today.year, 1, 1),
+      :amount => 100.50
+    }
+  end
+
+  should_belong_to :project
+  should_belong_to :user
+  should_have_many :time_entries
+  
+  should_validate_presence_of :user_id
+  should_validate_presence_of :date_in_effect
+  should_validate_numericality_of :amount
+
+  
+  context '#locked?' do
+    should 'should be true if a Time Entry is associated' do
+      rate = Rate.new
+      rate.time_entries << TimeEntry.generate!
+      assert rate.locked?
+    end
+    
+    should 'should be false if no Time Entries are associated' do
+      rate = Rate.new
+      assert ! rate.locked?
+    end
+  end
+  
+    
+  context '#unlocked?' do
+    should 'should be false if a Time Entry is associated' do
+      rate = Rate.new
+      rate.time_entries << TimeEntry.generate!
+      assert ! rate.unlocked?
+    end
+    
+    should 'should be true if no Time Entries are associated' do
+      rate = Rate.new
+      assert rate.unlocked?
+    end
+    
+  end
+
+  context '#save' do
+
+    should 'should save if a Rate is unlocked' do
+      rate = Rate.new(rate_valid_attributes)
+      assert rate.save
+    end
+
+    should 'should not save if a Rate is locked' do
+      rate = Rate.new(rate_valid_attributes)
+      rate.time_entries << TimeEntry.generate!
+      assert !rate.save
+    end
+  end
+  
+
+
+
+  context '#destroy' do
+
+    should 'should destroy the Rate if should is unlocked' do
+      rate = Rate.create(rate_valid_attributes)
+      assert_difference('Rate.count', -1) do
+        rate.destroy
+      end
+
+    end
+
+    should 'should not destroy the Rate if should is locked' do
+      rate = Rate.create(rate_valid_attributes)
+      rate.time_entries << TimeEntry.generate!
+
+      assert_difference('Rate.count', 0) do
+        rate.destroy
+      end
+    end
+  end
+
+  context '#for' do
+    setup do
+      @user = User.generate!
+      @project = Project.generate!
+      @date = '2009-01-01'
+      @date = Date.new(Date.today.year, 1, 1).to_s
+      @default_rate = Rate.generate!(:amount => 100.10, :date_in_effect => @date, :project => nil, :user => @user)
+      @rate = Rate.generate!(:amount => 50.50, :date_in_effect => @date, :project => @project, :user => @user)
+    end
+    
+    context 'parameters' do
+      should 'should be passed user' do
+        assert_raises ArgumentError do
+          Rate.for
+        end
+      end
+
+      should 'can be passed an optional project' do
+        assert_nothing_raised do
+          Rate.for(@user)
+        end
+
+        assert_nothing_raised do
+          Rate.for(@user, @project)
+        end
+      end
+      
+      should 'can be passed an optional date string' do
+        assert_nothing_raised do
+          Rate.for(@user)
+        end
+
+        assert_nothing_raised do
+          Rate.for(@user, nil, @date)
+        end
+      end
+      
+    end
+
+    context 'returns' do
+      should 'a Rate object when there is a rate' do
+        assert_equal @rate, Rate.for(@user, @project, @date)
+      end
+
+      should 'a nil when there is no rate' do
+        assert @rate.destroy
+        assert @default_rate.destroy
+        
+        assert_equal nil, Rate.for(@user, @project, @date)
+      end
+    end
+    
+    context 'with a user, project, and date' do
+      should 'should find the rate for a user on the project before the date' do
+        assert_equal @rate, Rate.for(@user, @project, @date)
+      end
+
+      should 'should return the most recent rate found' do
+        assert_equal @rate, Rate.for(@user, @project, @date)
+      end
+      
+      should 'should check for a default rate if no rate is found' do
+        assert @rate.destroy
+        
+        assert_equal @default_rate, Rate.for(@user, @project, @date)
+      end
+      
+      should 'should return nil if no set or default rate is found' do
+        assert @rate.destroy
+        assert @default_rate.destroy
+        
+        assert_equal nil, Rate.for(@user, @project, @date)
+      end
+    end
+
+    context 'with a user and project' do
+      should 'should find the rate for a user on the project before today' do
+        assert_equal @rate, Rate.for(@user, @project)
+      end
+
+      should 'should return the most recent rate found' do
+        assert_equal @rate, Rate.for(@user, @project)
+      end
+
+      should 'should return nil if no set or default rate is found' do
+        assert @rate.destroy
+        assert @default_rate.destroy
+
+        assert_equal nil, Rate.for(@user, @project)
+      end
+    end
+
+    context 'with a user' do
+      should 'should find the rate without a project for a user on the project before today' do
+        assert_equal @default_rate, Rate.for(@user)
+      end
+
+      should 'should return the most recent rate found' do
+        assert_equal @default_rate, Rate.for(@user)
+      end
+
+      should 'should return nil if no set or default rate is found' do
+        assert @rate.destroy
+        assert @default_rate.destroy
+
+        assert_equal nil, Rate.for(@user)
+      end
+    end
+    
+    should 'with an invalid user should raise an InvalidParameterException' do
+      object = Object.new
+      assert_raises Rate::InvalidParameterException do
+        Rate.for(object)
+      end
+    end
+    
+    should 'with an invalid project should raise an InvalidParameterException' do
+      object = Object.new
+      assert_raises Rate::InvalidParameterException do
+        Rate.for(@user, object)
+      end
+    end
+    
+    should 'with an invalid object for date should raise an InvalidParameterException' do
+      object = Object.new
+      assert_raises Rate::InvalidParameterException do
+        Rate.for(@user, @project, object)
+      end
+    end
+
+    should 'with an invalid date string should raise an InvalidParameterException' do
+      assert_raises Rate::InvalidParameterException do
+        Rate.for(@user, @project, '2000-13-40')
+      end
+    end
+
+  end
+  
+end