Merge branch 'refactor/add-policies' into 'master'

Refactor ability.rb into Policies

## What does this MR do?
Factors out `ability.rb` into a new abstraction - the "policy" (stored in `app/policies`). A policy is a class named `#{class_name}Policy` (looked up automatically as needed) that implements `rules` as follows:

``` ruby
class ThingPolicy < BasePolicy
  def rules
    @user # this is a user to determine abilities for, optionally nil in the anonymous case
    @subject # this is the subject of the ability, guaranteed to be an instance of `Thing`
    can! :some_ability # grant the :some_ability permission
    cannot! :some_ability # ensure that :some_ability is not allowed. this overrides any `can!` that is called before or after
    delegate! @subject.other_thing # merge the abilities (can!) and prohibitions (cannot!) from `@subject.other_thing`
    can? :some_ability # test whether, so far, :some_ability is allowed
  end

  def anonymous_rules
    # optional. if not implemented `rules` is called where `@user` is nil. otherwise this method is called when `@user` is nil.
  end
end
```

See merge request !5796

10 files changed, 64 insertions, 209 deletions

diff --git a/spec/controllers/projects/boards/issues_controller_spec.rb b/spec/controllers/projects/boards/issues_controller_spec.rb
index d0ad5e26dbd..2896636db5a 100644
--- a/spec/controllers/projects/boards/issues_controller_spec.rb
+++ b/spec/controllers/projects/boards/issues_controller_spec.rb
@@ -41,8 +41,8 @@ describe Projects::Boards::IssuesController do
 
     context 'with unauthorized user' do
       before do
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_project, project).and_return(true)
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_issue, project).and_return(false)
+        allow(Ability).to receive(:allowed?).with(user, :read_project, project).and_return(true)
+        allow(Ability).to receive(:allowed?).with(user, :read_issue, project).and_return(false)
       end
 
       it 'returns a successful 403 response' do
diff --git a/spec/controllers/projects/boards/lists_controller_spec.rb b/spec/controllers/projects/boards/lists_controller_spec.rb
index 261f35f28ed..d687dea3c3b 100644
--- a/spec/controllers/projects/boards/lists_controller_spec.rb
+++ b/spec/controllers/projects/boards/lists_controller_spec.rb
@@ -35,8 +35,8 @@ describe Projects::Boards::ListsController do
 
     context 'with unauthorized user' do
       before do
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_project, project).and_return(true)
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_list, project).and_return(false)
+        allow(Ability).to receive(:allowed?).with(user, :read_project, project).and_return(true)
+        allow(Ability).to receive(:allowed?).with(user, :read_list, project).and_return(false)
       end
 
       it 'returns a forbidden 403 response' do
diff --git a/spec/controllers/projects/boards_controller_spec.rb b/spec/controllers/projects/boards_controller_spec.rb
index 75a6d39e82c..6f6e608e1f3 100644
--- a/spec/controllers/projects/boards_controller_spec.rb
+++ b/spec/controllers/projects/boards_controller_spec.rb
@@ -23,8 +23,8 @@ describe Projects::BoardsController do
 
     context 'with unauthorized user' do
       before do
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_project, project).and_return(true)
-        allow(Ability.abilities).to receive(:allowed?).with(user, :read_board, project).and_return(false)
+        allow(Ability).to receive(:allowed?).with(user, :read_project, project).and_return(true)
+        allow(Ability).to receive(:allowed?).with(user, :read_board, project).and_return(false)
       end
 
       it 'returns a successful 404 response' do
diff --git a/spec/lib/banzai/reference_parser/base_parser_spec.rb b/spec/lib/banzai/reference_parser/base_parser_spec.rb
index ac9c66e2663..9095d2b1345 100644
--- a/spec/lib/banzai/reference_parser/base_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/base_parser_spec.rb
@@ -30,7 +30,7 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
       it 'returns the nodes if the attribute value equals the current project ID' do
         link['data-project'] = project.id.to_s
 
-        expect(Ability.abilities).not_to receive(:allowed?)
+        expect(Ability).not_to receive(:allowed?)
         expect(subject.nodes_visible_to_user(user, [link])).to eq([link])
       end
 
@@ -39,7 +39,7 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
 
         link['data-project'] = other_project.id.to_s
 
-        expect(Ability.abilities).to receive(:allowed?).
+        expect(Ability).to receive(:allowed?).
           with(user, :read_project, other_project).
           and_return(true)
 
@@ -57,7 +57,7 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
 
         link['data-project'] = other_project.id.to_s
 
-        expect(Ability.abilities).to receive(:allowed?).
+        expect(Ability).to receive(:allowed?).
           with(user, :read_project, other_project).
           and_return(false)
 
@@ -221,7 +221,7 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
     it 'delegates the permissions check to the Ability class' do
       user = double(:user)
 
-      expect(Ability.abilities).to receive(:allowed?).
+      expect(Ability).to receive(:allowed?).
         with(user, :read_project, project)
 
       subject.can?(user, :read_project, project)
diff --git a/spec/lib/banzai/reference_parser/user_parser_spec.rb b/spec/lib/banzai/reference_parser/user_parser_spec.rb
index 9a82891297d..4e7f82a6e09 100644
--- a/spec/lib/banzai/reference_parser/user_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/user_parser_spec.rb
@@ -82,7 +82,7 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
         end
 
         it 'returns the nodes if the user can read the group' do
-          expect(Ability.abilities).to receive(:allowed?).
+          expect(Ability).to receive(:allowed?).
             with(user, :read_group, group).
             and_return(true)
 
@@ -90,7 +90,7 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
         end
 
         it 'returns an empty Array if the user can not read the group' do
-          expect(Ability.abilities).to receive(:allowed?).
+          expect(Ability).to receive(:allowed?).
             with(user, :read_group, group).
             and_return(false)
 
@@ -103,7 +103,7 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
           it 'returns the nodes if the attribute value equals the current project ID' do
             link['data-project'] = project.id.to_s
 
-            expect(Ability.abilities).not_to receive(:allowed?)
+            expect(Ability).not_to receive(:allowed?)
 
             expect(subject.nodes_visible_to_user(user, [link])).to eq([link])
           end
@@ -113,7 +113,7 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
 
             link['data-project'] = other_project.id.to_s
 
-            expect(Ability.abilities).to receive(:allowed?).
+            expect(Ability).to receive(:allowed?).
               with(user, :read_project, other_project).
               and_return(true)
 
@@ -125,7 +125,7 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
 
             link['data-project'] = other_project.id.to_s
 
-            expect(Ability.abilities).to receive(:allowed?).
+            expect(Ability).to receive(:allowed?).
               with(user, :read_project, other_project).
               and_return(false)
 
diff --git a/spec/models/ability_spec.rb b/spec/models/ability_spec.rb
index c50ca38bdd9..b05510342bc 100644
--- a/spec/models/ability_spec.rb
+++ b/spec/models/ability_spec.rb
@@ -171,70 +171,6 @@ describe Ability, lib: true do
     end
   end
 
-  shared_examples_for ".project_abilities" do |enable_request_store|
-    before do
-      RequestStore.begin! if enable_request_store
-    end
-
-    after do
-      if enable_request_store
-        RequestStore.end!
-        RequestStore.clear!
-      end
-    end
-
-    describe '.project_abilities' do
-      let!(:project) { create(:empty_project, :public) }
-      let!(:user) { create(:user) }
-
-      it 'returns permissions for admin user' do
-        admin = create(:admin)
-
-        results = described_class.project_abilities(admin, project)
-
-        expect(results.count).to eq(68)
-      end
-
-      it 'returns permissions for an owner' do
-        results = described_class.project_abilities(project.owner, project)
-
-        expect(results.count).to eq(68)
-      end
-
-      it 'returns permissions for a master' do
-        project.team << [user, :master]
-
-        results = described_class.project_abilities(user, project)
-
-        expect(results.count).to eq(60)
-      end
-
-      it 'returns permissions for a developer' do
-        project.team << [user, :developer]
-
-        results = described_class.project_abilities(user, project)
-
-        expect(results.count).to eq(44)
-      end
-
-      it 'returns permissions for a guest' do
-        project.team << [user, :guest]
-
-        results = described_class.project_abilities(user, project)
-
-        expect(results.count).to eq(21)
-      end
-    end
-  end
-
-  describe '.project_abilities with RequestStore' do
-    it_behaves_like ".project_abilities", true
-  end
-
-  describe '.project_abilities without RequestStore' do
-    it_behaves_like ".project_abilities", false
-  end
-
   describe '.issues_readable_by_user' do
     context 'with an admin user' do
       it 'returns all given issues' do
@@ -286,12 +222,12 @@ describe Ability, lib: true do
   describe '.project_disabled_features_rules' do
     let(:project) { build(:project) }
 
-    subject { described_class.project_disabled_features_rules(project) }
+    subject { described_class.allowed(project.owner, project) }
 
     context 'wiki named abilities' do
       it 'disables wiki abilities if the project has no wiki' do
         expect(project).to receive(:has_wiki?).and_return(false)
-        expect(subject).to include(:read_wiki, :create_wiki, :update_wiki, :admin_wiki)
+        expect(subject).not_to include(:read_wiki, :create_wiki, :update_wiki, :admin_wiki)
       end
     end
   end
diff --git a/spec/models/members/project_member_spec.rb b/spec/models/members/project_member_spec.rb
index 913d74645a7..be57957b569 100644
--- a/spec/models/members/project_member_spec.rb
+++ b/spec/models/members/project_member_spec.rb
@@ -71,9 +71,6 @@ describe ProjectMember, models: true do
 
   describe :import_team do
     before do
-      @abilities = Six.new
-      @abilities << Ability
-
       @project_1 = create :project
       @project_2 = create :project
 
@@ -92,8 +89,8 @@ describe ProjectMember, models: true do
       it { expect(@project_2.users).to include(@user_1) }
       it { expect(@project_2.users).to include(@user_2) }
 
-      it { expect(@abilities.allowed?(@user_1, :create_project, @project_2)).to be_truthy }
-      it { expect(@abilities.allowed?(@user_2, :read_project, @project_2)).to be_truthy }
+      it { expect(Ability.allowed?(@user_1, :create_project, @project_2)).to be_truthy }
+      it { expect(Ability.allowed?(@user_2, :read_project, @project_2)).to be_truthy }
     end
 
     describe 'project 1 should not be changed' do
diff --git a/spec/models/note_spec.rb b/spec/models/note_spec.rb
index 9e8ae07e0b2..e6b6e7c0634 100644
--- a/spec/models/note_spec.rb
+++ b/spec/models/note_spec.rb
@@ -85,8 +85,6 @@ describe Note, models: true do
       @u1 = create(:user)
       @u2 = create(:user)
       @u3 = create(:user)
-      @abilities = Six.new
-      @abilities << Ability
     end
 
     describe 'read' do
@@ -95,9 +93,9 @@ describe Note, models: true do
         @p2.project_members.create(user: @u3, access_level: ProjectMember::GUEST)
       end
 
-      it { expect(@abilities.allowed?(@u1, :read_note, @p1)).to be_falsey }
-      it { expect(@abilities.allowed?(@u2, :read_note, @p1)).to be_truthy }
-      it { expect(@abilities.allowed?(@u3, :read_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u1, :read_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u2, :read_note, @p1)).to be_truthy }
+      it { expect(Ability.allowed?(@u3, :read_note, @p1)).to be_falsey }
     end
 
     describe 'write' do
@@ -106,9 +104,9 @@ describe Note, models: true do
         @p2.project_members.create(user: @u3, access_level: ProjectMember::DEVELOPER)
       end
 
-      it { expect(@abilities.allowed?(@u1, :create_note, @p1)).to be_falsey }
-      it { expect(@abilities.allowed?(@u2, :create_note, @p1)).to be_truthy }
-      it { expect(@abilities.allowed?(@u3, :create_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u1, :create_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u2, :create_note, @p1)).to be_truthy }
+      it { expect(Ability.allowed?(@u3, :create_note, @p1)).to be_falsey }
     end
 
     describe 'admin' do
@@ -118,9 +116,9 @@ describe Note, models: true do
         @p2.project_members.create(user: @u3, access_level: ProjectMember::MASTER)
       end
 
-      it { expect(@abilities.allowed?(@u1, :admin_note, @p1)).to be_falsey }
-      it { expect(@abilities.allowed?(@u2, :admin_note, @p1)).to be_truthy }
-      it { expect(@abilities.allowed?(@u3, :admin_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u1, :admin_note, @p1)).to be_falsey }
+      it { expect(Ability.allowed?(@u2, :admin_note, @p1)).to be_truthy }
+      it { expect(Ability.allowed?(@u3, :admin_note, @p1)).to be_falsey }
     end
   end
 
diff --git a/spec/models/project_security_spec.rb b/spec/models/project_security_spec.rb
deleted file mode 100644
index 36379074ea0..00000000000
--- a/spec/models/project_security_spec.rb
+++ /dev/null
@@ -1,112 +0,0 @@
-require 'spec_helper'
-
-describe Project, models: true do
-  describe 'authorization' do
-    before do
-      @p1 = create(:project)
-
-      @u1 = create(:user)
-      @u2 = create(:user)
-      @u3 = create(:user)
-      @u4 = @p1.owner
-
-      @abilities = Six.new
-      @abilities << Ability
-    end
-
-    let(:guest_actions) { Ability.project_guest_rules }
-    let(:report_actions) { Ability.project_report_rules }
-    let(:dev_actions) { Ability.project_dev_rules }
-    let(:master_actions) { Ability.project_master_rules }
-    let(:owner_actions) { Ability.project_owner_rules }
-
-    describe "Non member rules" do
-      it "denies for non-project users any actions" do
-        owner_actions.each do |action|
-          expect(@abilities.allowed?(@u1, action, @p1)).to be_falsey
-        end
-      end
-    end
-
-    describe "Guest Rules" do
-      before do
-        @p1.project_members.create(project: @p1, user: @u2, access_level: ProjectMember::GUEST)
-      end
-
-      it "allows for project user any guest actions" do
-        guest_actions.each do |action|
-          expect(@abilities.allowed?(@u2, action, @p1)).to be_truthy
-        end
-      end
-    end
-
-    describe "Report Rules" do
-      before do
-        @p1.project_members.create(project: @p1, user: @u2, access_level: ProjectMember::REPORTER)
-      end
-
-      it "allows for project user any report actions" do
-        report_actions.each do |action|
-          expect(@abilities.allowed?(@u2, action, @p1)).to be_truthy
-        end
-      end
-    end
-
-    describe "Developer Rules" do
-      before do
-        @p1.project_members.create(project: @p1, user: @u2, access_level: ProjectMember::REPORTER)
-        @p1.project_members.create(project: @p1, user: @u3, access_level: ProjectMember::DEVELOPER)
-      end
-
-      it "denies for developer master-specific actions" do
-        [dev_actions - report_actions].each do |action|
-          expect(@abilities.allowed?(@u2, action, @p1)).to be_falsey
-        end
-      end
-
-      it "allows for project user any dev actions" do
-        dev_actions.each do |action|
-          expect(@abilities.allowed?(@u3, action, @p1)).to be_truthy
-        end
-      end
-    end
-
-    describe "Master Rules" do
-      before do
-        @p1.project_members.create(project: @p1, user: @u2, access_level: ProjectMember::DEVELOPER)
-        @p1.project_members.create(project: @p1, user: @u3, access_level: ProjectMember::MASTER)
-      end
-
-      it "denies for developer master-specific actions" do
-        [master_actions - dev_actions].each do |action|
-          expect(@abilities.allowed?(@u2, action, @p1)).to be_falsey
-        end
-      end
-
-      it "allows for project user any master actions" do
-        master_actions.each do |action|
-          expect(@abilities.allowed?(@u3, action, @p1)).to be_truthy
-        end
-      end
-    end
-
-    describe "Owner Rules" do
-      before do
-        @p1.project_members.create(project: @p1, user: @u2, access_level: ProjectMember::DEVELOPER)
-        @p1.project_members.create(project: @p1, user: @u3, access_level: ProjectMember::MASTER)
-      end
-
-      it "denies for masters admin-specific actions" do
-        [owner_actions - master_actions].each do |action|
-          expect(@abilities.allowed?(@u2, action, @p1)).to be_falsey
-        end
-      end
-
-      it "allows for project owner any admin actions" do
-        owner_actions.each do |action|
-          expect(@abilities.allowed?(@u4, action, @p1)).to be_truthy
-        end
-      end
-    end
-  end
-end
diff --git a/spec/policies/project_policy_spec.rb b/spec/policies/project_policy_spec.rb
new file mode 100644
index 00000000000..eda1cafd65e
--- /dev/null
+++ b/spec/policies/project_policy_spec.rb
@@ -0,0 +1,36 @@
+require 'spec_helper'
+
+describe ProjectPolicy, models: true do
+  let(:project) { create(:empty_project, :public) }
+  let(:guest) { create(:user) }
+  let(:reporter) { create(:user) }
+  let(:dev) { create(:user) }
+  let(:master) { create(:user) }
+  let(:owner) { create(:user) }
+  let(:admin) { create(:admin) }
+
+  let(:users_ordered_by_permissions) do
+    [nil, guest, reporter, dev, master, owner, admin]
+  end
+
+  let(:users_permissions) do
+    users_ordered_by_permissions.map { |u| Ability.allowed(u, project).size }
+  end
+
+  before do
+    project.team << [guest, :guest]
+    project.team << [master, :master]
+    project.team << [dev, :developer]
+    project.team << [reporter, :reporter]
+
+    group = create(:group)
+    project.project_group_links.create(
+      group: group,
+      group_access: Gitlab::Access::MASTER)
+    group.add_owner(owner)
+  end
+
+  it 'returns increasing permissions for each level' do
+    expect(users_permissions).to eq(users_permissions.sort.uniq)
+  end
+end