Implement project collection service

Main purpose is move big amount of methods from user, group, project
models and place filtering logic in one place.
It also fixes 500 error on group page for PostgreSQL
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/controllers/groups_controller.rb

@@ -99,7 +99,7 @@ class GroupsController < ApplicationController
   end
 
   def projects
-    @projects ||= group.projects_accessible_to(current_user).sorted_by_activity
+    @projects ||= Projects::CollectService.new.execute(current_user, group: group)
   end
 
   def project_ids

app/models/ability.rb

@@ -184,7 +184,7 @@ class Ability
     def group_abilities user, group
       rules = []
 
-      if user.admin? || group.users.include?(user) || group.has_projects_accessible_to?(user)
+      if user.admin? || Projects::CollectService.new.execute(user, group: group).any?
         rules << :read_group
       end
 

app/models/project.rb

@@ -116,11 +116,18 @@ class Project < ActiveRecord::Base
   scope :personal, ->(user) { where(namespace_id: user.namespace_id) }
   scope :joined, ->(user) { where("namespace_id != ?", user.namespace_id) }
 
+  scope :public_only, -> { where(visibility_level: Project::PUBLIC) }
+  scope :public_and_internal_only, -> { where(visibility_level: Project.public_and_internal_levels) }
+
   scope :non_archived, -> { where(archived: false) }
 
   enumerize :issues_tracker, in: (Gitlab.config.issues_tracker.keys).append(:gitlab), default: :gitlab
 
   class << self
+    def public_and_internal_levels
+      [Project::PUBLIC, Project::INTERNAL]
+    end
+
     def abandoned
       where('projects.last_activity_at < ?', 6.months.ago)
     end

app/services/projects/collect_service.rb

+# Projects::CollectService class
+#
+# Used to collect projects user has access to
+#
+module Projects
+  class CollectService
+    def execute(current_user, options)
+      group = options[:group]
+
+      if group
+        group_projects(current_user, group)
+      else
+        all_projects(current_user)
+      end
+    end
+
+    private
+
+    def group_projects(current_user, group)
+      if current_user
+        if group.users.include?(current_user)
+          # User is group member
+          #
+          # Return ALL group projects
+          group.projects
+        else
+          projects_members = UsersProject.where(
+            project_id: group.projects,
+            user_id: current_user
+          )
+
+          if projects_members.any?
+            # User is a project member
+            #
+            # Return only:
+            #   public projects
+            #   internal projects
+            #   joined projects
+            #
+            group.projects.where(
+              "projects.id IN (?) OR projects.visibility_level IN (?)",
+              projects_members.pluck(:project_id),
+              Project.public_and_internal_levels
+            )
+          else
+            # User has no access to group or group projects
+            #
+            # Return only:
+            #   public projects
+            #   internal projects
+            #
+            group.projects.public_and_internal_only
+          end
+        end
+      else
+        # Not authenticated
+        #
+        # Return only:
+        #   public projects
+        group.projects.public_only
+      end
+    end
+  end
+
+  def all_projects
+    # TODO: implement
+    raise 'Not implemented yet'
+  end
+end

spec/services/projects_collect_service_spec.rb

+require 'spec_helper'
+
+describe Projects::CollectService do
+  let(:user) { create :user }
+  let(:group) { create :group }
+
+  let(:project1) { create(:empty_project, group: group, visibility_level: Project::PUBLIC) }
+  let(:project2) { create(:empty_project, group: group, visibility_level: Project::INTERNAL) }
+  let(:project3) { create(:empty_project, group: group, visibility_level: Project::PRIVATE) }
+  let(:project4) { create(:empty_project, group: group, visibility_level: Project::PRIVATE) }
+
+  context 'non authenticated' do
+    subject { Projects::CollectService.new.execute(nil, group: group) }
+
+    it { should include(project1) }
+    it { should_not include(project2) }
+    it { should_not include(project3) }
+    it { should_not include(project4) }
+  end
+
+  context 'authenticated' do
+    subject { Projects::CollectService.new.execute(user, group: group) }
+
+    it { should include(project1) }
+    it { should include(project2) }
+    it { should_not include(project3) }
+    it { should_not include(project4) }
+  end
+
+  context 'authenticated, project member' do
+    before { project3.team << [user, :developer] }
+
+    subject { Projects::CollectService.new.execute(user, group: group) }
+
+    it { should include(project1) }
+    it { should include(project2) }
+    it { should include(project3) }
+    it { should_not include(project4) }
+  end
+
+  context 'authenticated, group member' do
+    before { group.add_user(user, Gitlab::Access::DEVELOPER) }
+
+    subject { Projects::CollectService.new.execute(user, group: group) }
+
+    it { should include(project1) }
+    it { should include(project2) }
+    it { should include(project3) }
+    it { should include(project4) }
+  end
+end