Added support for named blueprints (after many, many requests.)

Author: notahat

README.markdown

@@ -244,6 +244,28 @@ You can also call plan on has\_many associations, making it easy to test nested
     end
 
 
+### Named Blueprints
+
+Named blueprints let you define variations on an object. For example, suppose some of your Users are administrators:
+
+    User.blueprint do
+      name
+      email
+    end
+    
+    User.blueprint(:admin) do
+      name  { Sham.name + " (admin)" }
+      admin { true }
+    end
+
+Calling:
+
+    User.make(:admin)
+
+will use the `:admin` blueprint.
+
+Named blueprints call the default blueprint to set any attributes not specifically provided, so in this example the `email` attribute will still be generated even for an admin user.
+
 
 FAQ
 ---
@@ -264,33 +286,6 @@ This will result in Machinist attempting to run ruby's open command. To work aro
       self.open { Time.now }
     end
 
-### I'm a factory_girl user, and I like having multiple factories for a single model. Can Machinist do the same thing?
-
-Short answer: no.
-
-Machinist blueprints are a little different to factory_girl's factories. Your blueprint should only specify how to generate values for attributes that you don't care about. If you care about an attribute's value, then it doesn't belong in the blueprint.
-
-If you have want to construct objects with similar attributes in a number of tests, just make a test helper. For example:
-
-    User.blueprint do
-      login
-      password
-    end
-    
-    def make_admin_user(attributes = {})
-      User.make(attributes.merge(:role => :admin))
-    end
-
-This keeps the blueprint very clean and generic, and also makes it clear what differentiates an admin user from a generic user.
-
-If you want to make this look a bit cleaner in your tests, you can try the following in your blueprint:
-
-    class User
-      def self.make_admin(attributes = {})
-        make(attributes.merge(:role => :admin)
-      end
-    end
-
 
 Credits
 -------

lib/machinist.rb

@@ -9,10 +9,13 @@ module Machinist
   #
   # The blueprint is instance_eval'd against the Lathe.
   class Lathe
-    def self.run(object, attributes = {})
-      blueprint = object.class.blueprint
+    def self.run(object, *args)
+      blueprint       = object.class.blueprint
+      named_blueprint = object.class.blueprint(args.shift) if args.first.is_a?(Symbol)
+      attributes = args.pop || {}
       raise "No blueprint for class #{object.class}" if blueprint.nil?
       returning self.new(object, attributes) do |lathe|
+        lathe.instance_eval(&named_blueprint) if named_blueprint
         lathe.instance_eval(&blueprint)
       end
     end

lib/machinist/active_record.rb

@@ -51,45 +51,46 @@ def self.included(base)
       end
 
       module ClassMethods
-        def blueprint(&blueprint)
-          @blueprint = blueprint if block_given?
-          @blueprint
+        def blueprint(name = :master, &blueprint)
+          @blueprints ||= {}
+          @blueprints[name] = blueprint if block_given?
+          @blueprints[name]
         end
 
-        def make(attributes = {}, &block)
-          lathe = Lathe.run(self.new, attributes)
+        def make(*args, &block)
+          lathe = Lathe.run(self.new, *args)
           unless Machinist::ActiveRecord.nerfed?
             lathe.object.save!
             lathe.object.reload
           end
           lathe.object(&block)
         end
 
-        def make_unsaved(attributes = {})
-          returning(Machinist::ActiveRecord.with_save_nerfed { make(attributes) }) do |object|
+        def make_unsaved(*args)
+          returning(Machinist::ActiveRecord.with_save_nerfed { make(*args) }) do |object|
             yield object if block_given?
           end
         end
 
-        def plan(attributes = {})
-          lathe = Lathe.run(self.new, attributes)
+        def plan(*args)
+          lathe = Lathe.run(self.new, *args)
           Machinist::ActiveRecord.assigned_attributes_without_associations(lathe)
         end
       end
     end
 
     module BelongsToExtensions
-      def make(attributes = {}, &block)
-        lathe = Lathe.run(self.build, attributes)
+      def make(*args, &block)
+        lathe = Lathe.run(self.build, *args)
         unless Machinist::ActiveRecord.nerfed?
           lathe.object.save!
           lathe.object.reload
         end
         lathe.object(&block)
       end
 
-      def plan(attributes = {})
-        lathe = Lathe.run(self.build, attributes)
+      def plan(*args)
+        lathe = Lathe.run(self.build, *args)
         Machinist::ActiveRecord.assigned_attributes_without_associations(lathe)
       end
     end

spec/db/schema.rb

@@ -3,6 +3,7 @@
     t.column :name, :string
     t.column :type, :string
     t.column :password, :string
+    t.column :admin, :boolean, :default => false
   end
 
   create_table :posts, :force => true do |t|

spec/machinist_spec.rb

@@ -26,7 +26,7 @@ class Comment < ActiveRecord::Base
       end
       Person.make.name.should == "Fred"
     end
-  
+    
     it "should set an attribute on the constructed object from a block in the blueprint" do
       Person.blueprint do
         name { "Fred" }
@@ -119,6 +119,32 @@ class Comment < ActiveRecord::Base
       Person.blueprint { type "Person" }
       Person.make.type.should == "Person"
     end
+    
+    describe "for named blueprints" do
+      before do
+        @block_called = false
+        Person.blueprint do
+          name  { "Fred" }
+          admin { block_called = true; false }
+        end
+        Person.blueprint(:admin) do
+          admin { true }
+        end
+        @person = Person.make(:admin)
+      end
+      
+      it "should override an attribute from the parent blueprint in the child blueprint" do
+        @person.admin.should == true
+      end
+      
+      it "should not call the block for an attribute from the parent blueprint if that attribute is overridden in the child" do
+        @block_called.should be_false
+      end
+      
+      it "should set an attribute defined in the parent blueprint" do
+        @person.name.should == "Fred"
+      end
+    end
 
   end # make method