ProjectGroupLink model with migration and specs

app/models/project.rb

@@ -67,6 +67,9 @@ class Project < ActiveRecord::Base
   has_many :deploy_keys_projects, dependent: :destroy
   has_many :deploy_keys, through: :deploy_keys_projects
 
+  has_many :project_group_links_path, dependent: :destroy
+  has_many :invited_groups, through: :project_group_links, source: 'group'
+
   delegate :name, to: :owner, allow_nil: true, prefix: true
   delegate :members, to: :team, prefix: true
 

app/models/project_group_link.rb

+#-------------------------------------------------------------------
+#
+# The GitLab Enterprise Edition (EE) license
+#
+# Copyright (c) 2013 GitLab.com
+#
+# All Rights Reserved. No part of this software may be reproduced without
+# prior permission of GitLab.com. By using this software you agree to be
+# bound by the GitLab Enterprise Support Subscription Terms.
+#
+#-------------------------------------------------------------------
+
+class ProjectGroupLink < ActiveRecord::Base
+  belongs_to :project
+  belongs_to :group
+
+  validates :project_id, presence: true
+  validates :group_id, presence: true
+  validates :group_id, uniqueness: { scope: [:project_id], message: "already shared with this group" }
+end

db/migrate/20130711063759_create_project_group_links.rb

+class CreateProjectGroupLinks < ActiveRecord::Migration
+  def change
+    create_table :project_group_links do |t|
+      t.integer :project_id, null: false
+      t.integer :group_id, null: false
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20130624162710) do
+ActiveRecord::Schema.define(:version => 20130711063759) do
 
   create_table "deploy_keys_projects", :force => true do |t|
     t.integer  "deploy_key_id", :null => false
@@ -157,6 +157,13 @@ ActiveRecord::Schema.define(:version => 20130624162710) do
   add_index "notes", ["project_id", "noteable_type"], :name => "index_notes_on_project_id_and_noteable_type"
   add_index "notes", ["project_id"], :name => "index_notes_on_project_id"
 
+  create_table "project_group_links", :force => true do |t|
+    t.integer  "project_id", :null => false
+    t.integer  "group_id",   :null => false
+    t.datetime "created_at", :null => false
+    t.datetime "updated_at", :null => false
+  end
+
   create_table "projects", :force => true do |t|
     t.string   "name"
     t.string   "path"

spec/factories/project_group_links.rb

+FactoryGirl.define do
+  factory :project_group_link do
+    project
+    group
+  end
+end

spec/models/project_group_link_spec.rb

+require 'spec_helper'
+
+describe ProjectGroupLink do
+  describe "Associations" do
+    it { should belong_to(:group) }
+    it { should belong_to(:project) }
+  end
+
+  describe "Mass assignment" do
+    it { should_not allow_mass_assignment_of(:group_id) }
+    it { should_not allow_mass_assignment_of(:project_id) }
+  end
+
+  describe "Validation" do
+    let!(:project_group_link) { create(:project_group_link) }
+
+    it { should validate_presence_of(:project_id) }
+    it { should validate_uniqueness_of(:group_id).scoped_to(:project_id).with_message(/already shared/) }
+    it { should validate_presence_of(:group_id) }
+  end
+end