More initial changes.

remarkable_datamapper/lib/remarkable_datamapper/base.rb

@@ -64,7 +64,7 @@ def assert_good_or_bad_if_key(key, value, message_key=:message) #:nodoc:
         # Default allow_nil? validation. It accepts the message_key which is
         # the key which contain the message in @options.
         #
-        # It also gets an allow_nil message on remarkable.active_record.allow_nil
+        # It also gets an allow_nil message on remarkable.data_mapper.allow_nil
         # to be used as default.
         #
         def allow_nil?(message_key=:message) #:nodoc:
@@ -74,7 +74,7 @@ def allow_nil?(message_key=:message) #:nodoc:
         # Default allow_blank? validation. It accepts the message_key which is
         # the key which contain the message in @options.
         #
-        # It also gets an allow_blank message on remarkable.active_record.allow_blank
+        # It also gets an allow_blank message on remarkable.data_mapper.allow_blank
         # to be used as default.
         #
         def allow_blank?(message_key=:message) #:nodoc:
@@ -93,7 +93,7 @@ def bad?(value, message_sym=:message) #:nodoc:
           assert_bad_value(@subject, @attribute, value, @options[message_sym])
         end
 
-        # Asserts that an Active Record model validates with the passed
+        # Asserts that a DataMapper model validates with the passed
         # <tt>value</tt> by making sure the <tt>error_message_to_avoid</tt> is not
         # contained within the list of errors for that attribute.
         #
@@ -119,7 +119,7 @@ def assert_good_value(model, attribute, value, error_message_to_avoid=//) # :nod
           assert_does_not_contain(model.errors.on(attribute), error_message_to_avoid)
         end
 
-        # Asserts that an Active Record model invalidates the passed
+        # Asserts that a DataMapper model invalidates the passed
         # <tt>value</tt> by making sure the <tt>error_message_to_expect</tt> is
         # contained within the list of errors for that attribute.
         #
@@ -173,7 +173,7 @@ def assert_bad_value(model, attribute, value, error_message_to_expect=:invalid)
         #   macros would start to pass when they shouldn't.
         #
         #   Using the underlying mechanism inside DataMapper makes us free from
-        #   all thos errors.
+        #   all those errors.
         #
         # We replace {{count}} interpolation for 12345 which later is replaced
         # by a regexp which contains \d+.

remarkable_datamapper/lib/remarkable_datamapper/matchers/validates_is_unique.rb

@@ -0,0 +1,233 @@
+module Remarkable
+  module DataMapper
+    module Matchers
+      class ValidatesIsUniqueMatcher < Remarkable::DataMapper::Base #:nodoc:
+        arguments :collection => :attributes, :as => :attribute
+
+        optional :message
+        optional :scope, :splat => true
+        optional :case_sensitive, :allow_nil, :allow_blank, :default => true
+
+        collection_assertions :find_first_object?, :responds_to_scope?, :is_unique?, :case_sensitive?,
+                              :valid_with_new_scope?, :allow_nil?, :allow_blank?
+
+        default_options :message => :taken
+
+        before_assert do
+          @options[:scope] = [*@options[:scope]].compact if @options[:scope]
+        end
+
+        private
+
+          # Tries to find an object in the database. If allow_nil and/or allow_blank
+          # is given, we must find a record which is not nil or not blank.
+          #
+          # We should also ensure that the object retrieved from the database
+          # is not the @subject.
+          #
+          # If any of these attempts fail, an error is raised.
+          #
+          def find_first_object?
+            conditions, message = if @options[:allow_nil]
+              [ ["#{@attribute} IS NOT NULL"], " with #{@attribute} not nil" ]
+            elsif @options[:allow_blank]
+              [ ["#{@attribute} != ''"], " with #{@attribute} not blank" ]
+            else
+              [ [], "" ]
+            end
+
+            unless @subject.new_record?
+              primary_key = subject_class.primary_key
+
+              message    << " which is different from the subject record (the object being validated is the same as the one in the database)"
+              conditions << "#{subject_class.primary_key} != '#{@subject.send(primary_key)}'"
+            end
+
+            options = conditions.empty? ? {} : { :conditions => conditions.join(' AND ') }
+
+            return true if @existing = subject_class.find(:first, options)
+            raise ScriptError, "could not find a #{subject_class} record in the database" + message
+          end
+
+          # Set subject scope to be equal to the object found.
+          #
+          def responds_to_scope?
+            (@options[:scope] || []).each do |scope|
+              setter = :"#{scope}="
+
+              return false, :method => setter unless @subject.respond_to?(setter)
+              return false, :method => scope  unless @existing.respond_to?(scope)
+
+              @subject.send(setter, @existing.send(scope))
+            end
+            true
+          end
+
+          # Check if the attribute given is valid and if the validation fails for equal values.
+          #
+          def is_unique?
+            @value = @existing.send(@attribute)
+            return bad?(@value)
+          end
+
+          # If :case_sensitive is given and it's false, we swap the case of the
+          # value used in :is_unique? and see if the test object remains valid.
+          #
+          # If :case_sensitive is given and it's true, we swap the case of the
+          # value used in is_unique? and see if the test object is not valid.
+          #
+          # This validation will only occur if the test object is a String.
+          # 
+          def case_sensitive?
+            return true unless @value.is_a?(String)
+            assert_good_or_bad_if_key(:case_sensitive, @value.swapcase)
+          end
+
+          # Now test that the object is valid when changing the scoped attribute.
+          #
+          def valid_with_new_scope?
+            (@options[:scope] || []).each do |scope|
+              setter = :"#{scope}="
+
+              previous_scope_value = @subject.send(scope)
+              @subject.send(setter, new_value_for_scope(scope))
+              return false, :method => scope unless good?(@value)
+
+              @subject.send(setter, previous_scope_value)
+            end
+            true
+          end
+
+          # Change the existing object attribute to nil to run allow nil
+          # validations. If we find any problem while updating the @existing
+          # record, it's because we can't save nil values in the database. So it
+          # passes when :allow_nil is false, but should raise an error when
+          # :allow_nil is true
+          #
+          def allow_nil?
+            return true unless @options.key?(:allow_nil)
+
+            begin
+              @existing.update_attribute(@attribute, nil)
+            rescue ::ActiveRecord::StatementInvalid => e
+              raise ScriptError, "You declared that #{@attribute} accepts nil values in validate_uniqueness_of, " <<
+                                 "but I cannot save nil values in the database, got: #{e.message}" if @options[:allow_nil]
+              return true
+            end
+
+            super
+          end
+
+          # Change the existing object attribute to blank to run allow blank
+          # validation. It uses the same logic as :allow_nil.
+          #
+          def allow_blank?
+            return true unless @options.key?(:allow_blank)
+
+            begin
+              @existing.update_attribute(@attribute, '')
+            rescue ::ActiveRecord::StatementInvalid => e
+              raise ScriptError, "You declared that #{@attribute} accepts blank values in validate_uniqueness_of, " <<
+                                 "but I cannot save blank values in the database, got: #{e.message}" if @options[:allow_blank]
+              return true
+            end
+
+            super
+          end
+
+          # Returns a value to be used as new scope. It deals with four different
+          # cases: date, time, boolean and stringfiable (everything that can be
+          # converted to a string and the next value makes sense)
+          #
+          def new_value_for_scope(scope)
+            column_type = if @existing.respond_to?(:column_for_attribute)
+              @existing.column_for_attribute(scope)
+            else
+              nil
+            end
+
+            case column_type.type
+              when :int, :integer, :float, :decimal
+                new_value_for_stringfiable_scope(scope)
+              when :datetime, :timestamp, :time
+                Time.now + 10000
+              when :date
+                Date.today + 100
+              when :boolean
+                !@existing.send(scope)
+              else
+                new_value_for_stringfiable_scope(scope)
+            end
+          end
+
+          # Returns a value to be used as scope by generating a range of values
+          # and searching for them in the database.
+          #
+          def new_value_for_stringfiable_scope(scope)
+            values = [(@existing.send(scope) || 999).next.to_s]
+
+            # Generate a range of values to search in the database
+            100.times do
+              values << values.last.next
+            end
+            conditions = { scope => values, @attribute => @value }
+
+            # Get values from the database, get the scope attribute and map them to string.
+            db_values = subject_class.find(:all, :conditions => conditions, :select => scope)
+            db_values.map!{ |r| r.send(scope).to_s }
+
+            if value_to_return = (values - db_values).first
+              value_to_return
+            else
+              raise ScriptError, "Tried to find an unique scope value for #{scope} but I could not. " << 
+                                 "The conditions hash was #{conditions.inspect} and it returned all records."
+            end
+          end
+      end
+
+      # Ensures that the model cannot be saved if one of the attributes listed
+      # is not unique.
+      #
+      # Requires an existing record in the database. If you supply :allow_nil as
+      # option, you need to have in the database a record which is not nil in the
+      # given attributes. The same is required for allow_blank option.
+      #
+      # Notice that the record being validate should not be the same as in the
+      # database. In other words, you can't do this:
+      #
+      #   subject { Post.create!(@valid_attributes) }
+      #   should_validate_uniqueness_of :title
+      #
+      # But don't worry, if you eventually do that, a helpful error message
+      # will be raised.
+      #
+      # == Options
+      #
+      # * <tt>:scope</tt> - field(s) to scope the uniqueness to.
+      # * <tt>:case_sensitive</tt> - the matcher look for an exact match.
+      # * <tt>:allow_nil</tt> - when supplied, validates if it allows nil or not.
+      # * <tt>:allow_blank</tt> - when supplied, validates if it allows blank or not.
+      # * <tt>:message</tt> - value the test expects to find in <tt>errors.on(:attribute)</tt>.
+      #   Regexp, string or symbol.  Default = <tt>I18n.translate('activerecord.errors.messages.taken')</tt>
+      #
+      # == Examples
+      #
+      #   it { should validate_uniqueness_of(:keyword, :username) }
+      #   it { should validate_uniqueness_of(:email, :scope => :name, :case_sensitive => false) }
+      #   it { should validate_uniqueness_of(:address, :scope => [:first_name, :last_name]) }
+      #
+      #   should_validate_uniqueness_of :keyword, :username
+      #   should_validate_uniqueness_of :email, :scope => :name, :case_sensitive => false
+      #   should_validate_uniqueness_of :address, :scope => [:first_name, :last_name]
+      #
+      #   should_validate_uniqueness_of :email do |m|
+      #     m.scope = name
+      #     m.case_sensitive = false
+      #   end
+      #
+      def validates_is_unique(*attributes, &block)
+        ValidateUniquenessOfMatcher.new(*attributes, &block).spec(self)
+      end
+    end
+  end
+end