add :zero option and tests

lib/bitmask_attributes.rb

@@ -9,7 +9,7 @@ def bitmask(attribute, options={}, &extension)
       unless options[:as] && options[:as].kind_of?(Array)
         raise ArgumentError, "Must provide an Array :as option"
       end
-      bitmask_definitions[attribute] = Definition.new(attribute, options[:as].to_a,options[:null].nil? || options[:null], &extension)
+      bitmask_definitions[attribute] = Definition.new(attribute, options[:as].to_a,options[:null].nil? || options[:null],options[:zero],&extension)
       bitmask_definitions[attribute].install_on(self)
     end
 

lib/bitmask_attributes/definition.rb

@@ -1,12 +1,13 @@
 module BitmaskAttributes
   class Definition
-    attr_reader :attribute, :values, :allow_null, :extension
+    attr_reader :attribute, :values, :allow_null, :zero_value, :extension
 
-    def initialize(attribute, values=[],allow_null = true, &extension)
+    def initialize(attribute, values=[],allow_null = true,zero_value = nil, &extension)
       @attribute = attribute
       @values = values
       @extension = extension
       @allow_null = allow_null
+      @zero_value = zero_value
     end
 
     def install_on(model)
@@ -57,7 +58,7 @@ def override_setter_on(model)
         model.class_eval %(
           def #{attribute}=(raw_value)
             values = raw_value.kind_of?(Array) ? raw_value : [raw_value]
-            self.#{attribute}.replace(values.reject(&:blank?))
+            self.#{attribute}.replace(values.reject{|value| #{eval_string_for_zero('value')}})
           end
         )
       end
@@ -75,7 +76,9 @@ def create_convenience_class_method_on(model)
         model.class_eval %(
           def self.bitmask_for_#{attribute}(*values)
             values.inject(0) do |bitmask, value|
-              unless (bit = bitmasks[:#{attribute}][value])
+              if #{eval_string_for_zero('value')}
+                bit = 0
+              elsif (bit = bitmasks[:#{attribute}][value]).nil?
                 raise ArgumentError, "Unsupported value for #{attribute}: \#{value.inspect}"
               end
               bitmask | bit
@@ -106,10 +109,7 @@ def #{attribute}?(*values)
       end
 
       def create_scopes_on(model)
-        if allow_null
-          or_is_null_condition = " OR #{attribute} IS NULL"
-          or_is_not_null_condition = " OR #{attribute} IS NOT NULL"
-        end
+        or_is_null_condition = " OR #{attribute} IS NULL" if allow_null
 
         model.class_eval %(
           scope :with_#{attribute},
@@ -160,5 +160,9 @@ def create_scopes_on(model)
           )
         end      
       end
+
+      def eval_string_for_zero(value_string)
+        zero_value ? "#{value_string}.blank? || #{value_string} == :#{zero_value}" : "#{value_string}.blank?"
+      end
   end
 end

test/bitmask_attributes_test.rb

@@ -105,6 +105,7 @@ def self.context_with_classes(label,campaign_class,company_class)
       end
 
       should "ignore blanks fed as values" do
+        assert_equal 0b11,@campaign_class.bitmask_for_medium(:web, :print, '')
         campaign = @campaign_class.new(:medium => [:web, :print, ''])
         assert_stored campaign, :web, :print
       end
@@ -232,6 +233,23 @@ def self.context_with_classes(label,campaign_class,company_class)
         assert_equal [campaign], @campaign_class.no_medium
       end
 
+      should "allow zero in values without changing result" do
+        assert_equal 0,@campaign_class.bitmask_for_allow_zero(:none)
+        assert_equal 0b111,@campaign_class.bitmask_for_allow_zero(:one,:two,:three,:none)
+
+        campaign = @campaign_class.new(:allow_zero => :none)
+        assert campaign.save
+        assert_equal [],campaign.allow_zero
+
+        campaign.allow_zero = :none
+        assert campaign.save
+        assert_equal [],campaign.allow_zero
+
+        campaign.allow_zero = [:one,:none]
+        assert campaign.save
+        assert_equal [:one],campaign.allow_zero
+      end
+
 
       private
 

test/support/models.rb

@@ -1,14 +1,14 @@
 ActiveRecord::Schema.define do 
   create_table :campaign_with_nulls do |t|
     t.integer :company_id
-    t.integer :medium, :misc, :Legacy
+    t.integer :medium, :allow_zero, :misc, :Legacy
   end
   create_table :company_with_nulls do |t|
     t.string :name
   end
   create_table :campaign_without_nulls do |t|
     t.integer :company_id
-    t.integer :medium, :misc, :Legacy, :null => false, :default => 0
+    t.integer :medium, :allow_zero, :misc, :Legacy, :null => false, :default => 0
   end
   create_table :company_without_nulls do |t|
     t.string :name
@@ -24,6 +24,7 @@ class CompanyWithNull < ActiveRecord::Base
 class CampaignWithNull < ActiveRecord::Base
   belongs_to :company,:class_name => 'CompanyWithNull'
   bitmask :medium, :as => [:web, :print, :email, :phone]
+  bitmask :allow_zero, :as => [:one, :two, :three], :zero => :none
   bitmask :misc, :as => %w(some useless values) do
     def worked?
       true
@@ -39,6 +40,7 @@ class CompanyWithoutNull < ActiveRecord::Base
 class CampaignWithoutNull < ActiveRecord::Base
   belongs_to :company,:class_name => 'CompanyWithoutNull'
   bitmask :medium, :as => [:web, :print, :email, :phone], :null => false
+  bitmask :allow_zero, :as => [:one, :two, :three], :zero => :none, :null => false
   bitmask :misc, :as => %w(some useless values), :null => false do
     def worked?
       true