Merge branch...

Merge branch '31273-creating-an-project-within-an-internal-sub-group-gives-the-option-to-set-it-a-public' into 'master'

Resolve various visibility level settings issues

Closes #31273

See merge request !13442

app/assets/javascripts/commons/polyfills.js

@@ -12,3 +12,4 @@ import 'core-js/fn/symbol';
 // Browser polyfills
 import './polyfills/custom_event';
 import './polyfills/element';
+import './polyfills/nodelist';

app/assets/javascripts/commons/polyfills/nodelist.js

+if (window.NodeList && !NodeList.prototype.forEach) {
+  NodeList.prototype.forEach = function forEach(callback, thisArg = window) {
+    for (let i = 0; i < this.length; i += 1) {
+      callback.call(thisArg, this[i], i, this);
+    }
+  };
+}

app/assets/javascripts/dispatcher.js

@@ -74,6 +74,7 @@ import PerformanceBar from './performance_bar';
 import initNotes from './init_notes';
 import initLegacyFilters from './init_legacy_filters';
 import initIssuableSidebar from './init_issuable_sidebar';
+import initProjectVisibilitySelector from './project_visibility';
 import GpgBadges from './gpg_badges';
 import UserFeatureHelper from './helpers/user_feature_helper';
 import initChangesDropdown from './init_changes_dropdown';
@@ -575,6 +576,7 @@ import initChangesDropdown from './init_changes_dropdown';
               break;
             case 'new':
               new ProjectNew();
+              initProjectVisibilitySelector();
               break;
             case 'show':
               new Star();

app/assets/javascripts/project_visibility.js

+function setVisibilityOptions(namespaceSelector) {
+  if (!namespaceSelector || !('selectedIndex' in namespaceSelector)) {
+    return;
+  }
+  const selectedNamespace = namespaceSelector.options[namespaceSelector.selectedIndex];
+  const { name, visibility, visibilityLevel, showPath, editPath } = selectedNamespace.dataset;
+
+  document.querySelectorAll('.visibility-level-setting .radio').forEach((option) => {
+    const optionInput = option.querySelector('input[type=radio]');
+    const optionValue = optionInput ? optionInput.value : 0;
+    const optionTitle = option.querySelector('.option-title');
+    const optionName = optionTitle ? optionTitle.innerText.toLowerCase() : '';
+
+    // don't change anything if the option is restricted by admin
+    if (!option.classList.contains('restricted')) {
+      if (visibilityLevel < optionValue) {
+        option.classList.add('disabled');
+        optionInput.disabled = true;
+        const reason = option.querySelector('.option-disabled-reason');
+        if (reason) {
+          reason.innerHTML =
+            `This project cannot be ${optionName} because the visibility of
+            <a href="${showPath}">${name}</a> is ${visibility}. To make this project
+            ${optionName}, you must first <a href="${editPath}">change the visibility</a>
+            of the parent group.`;
+        }
+      } else {
+        option.classList.remove('disabled');
+        optionInput.disabled = false;
+      }
+    }
+  });
+}
+
+export default function initProjectVisibilitySelector() {
+  const namespaceSelector = document.querySelector('select.js-select-namespace');
+  if (namespaceSelector) {
+    $('.select2.js-select-namespace').on('change', () => setVisibilityOptions(namespaceSelector));
+    setVisibilityOptions(namespaceSelector);
+  }
+}

app/assets/stylesheets/pages/projects.scss

@@ -299,28 +299,6 @@
   }
 }
 
-.project-visibility-level-holder {
-  .radio {
-    margin-bottom: 10px;
-
-    i {
-      margin: 2px 0;
-      font-size: 20px;
-    }
-
-    .option-title {
-      font-weight: $gl-font-weight-normal;
-      display: inline-block;
-      color: $gl-text-color;
-    }
-
-    .option-descr {
-      margin-left: 29px;
-      color: $project-option-descr-color;
-    }
-  }
-}
-
 .save-project-loader {
   margin-top: 50px;
   margin-bottom: 50px;

app/assets/stylesheets/pages/settings.scss

@@ -143,6 +143,47 @@
   }
 }
 
+.visibility-level-setting {
+  .radio {
+    margin-bottom: 10px;
+
+    i.fa {
+      margin: 2px 0;
+      font-size: 20px;
+    }
+
+    .option-title {
+      font-weight: $gl-font-weight-normal;
+      display: inline-block;
+      color: $gl-text-color;
+    }
+
+    .option-description,
+    .option-disabled-reason {
+      margin-left: 29px;
+      color: $project-option-descr-color;
+    }
+
+    .option-disabled-reason {
+      display: none;
+    }
+
+    &.disabled {
+      i.fa {
+        opacity: 0.5;
+      }
+
+      .option-description {
+        display: none;
+      }
+
+      .option-disabled-reason {
+        display: block;
+      }
+    }
+  }
+}
+
 .prometheus-metrics-monitoring {
   .panel {
     .panel-toggle {

app/controllers/projects_controller.rb

@@ -20,7 +20,10 @@ class ProjectsController < Projects::ApplicationController
   end
 
   def new
-    @project = Project.new
+    namespace = Namespace.find_by(id: params[:namespace_id]) if params[:namespace_id]
+    return access_denied! if namespace && !can?(current_user, :create_projects, namespace)
+
+    @project = Project.new(namespace_id: namespace&.id)
   end
 
   def edit

app/helpers/namespaces_helper.rb

@@ -4,7 +4,8 @@ module NamespacesHelper
   end
 
   def namespaces_options(selected = :current_user, display_path: false, extra_group: nil)
-    groups = current_user.owned_groups + current_user.masters_groups
+    groups  = current_user.owned_groups + current_user.masters_groups
+    users   = [current_user.namespace]
 
     unless extra_group.nil? || extra_group.is_a?(Group)
       extra_group = Group.find(extra_group) if Namespace.find(extra_group).kind == 'group'
@@ -14,22 +15,9 @@ module NamespacesHelper
       groups |= [extra_group]
     end
 
-    users = [current_user.namespace]
-
-    data_attr_group = { 'data-options-parent' => 'groups' }
-    data_attr_users = { 'data-options-parent' => 'users' }
-
-    group_opts = [
-      "Groups", groups.sort_by(&:human_name).map { |g| [display_path ? g.full_path : g.human_name, g.id, data_attr_group] }
-    ]
-
-    users_opts = [
-      "Users", users.sort_by(&:human_name).map { |u| [display_path ? u.path : u.human_name, u.id, data_attr_users] }
-    ]
-
     options = []
-    options << group_opts
-    options << users_opts
+    options << options_for_group(groups, display_path: display_path, type: 'group')
+    options << options_for_group(users, display_path: display_path, type: 'user')
 
     if selected == :current_user && current_user.namespace
       selected = current_user.namespace.id
@@ -45,4 +33,23 @@ module NamespacesHelper
       avatar_icon(namespace.owner.email, size)
     end
   end
+
+  private
+
+  def options_for_group(namespaces, display_path:, type:)
+    group_label = type.pluralize
+    elements = namespaces.sort_by(&:human_name).map! do |n|
+      [display_path ? n.full_path : n.human_name, n.id,
+       data: {
+         options_parent: group_label,
+         visibility_level: n.visibility_level_value,
+         visibility: n.visibility,
+         name: n.name,
+         show_path: (type == 'group') ? group_path(n) : user_path(n),
+         edit_path: (type == 'group') ? edit_group_path(n) : nil
+       }]
+    end
+
+    [group_label.camelize, elements]
+  end
 end

app/helpers/visibility_level_helper.rb

@@ -63,6 +63,68 @@ module VisibilityLevelHelper
     end
   end
 
+  def restricted_visibility_level_description(level)
+    level_name = Gitlab::VisibilityLevel.level_name(level)
+    "#{level_name.capitalize} visibility has been restricted by the administrator."
+  end
+
+  def disallowed_visibility_level_description(level, form_model)
+    case form_model
+    when Project
+      disallowed_project_visibility_level_description(level, form_model)
+    when Group
+      disallowed_group_visibility_level_description(level, form_model)
+    end
+  end
+
+  # Note: these messages closely mirror the form validation strings found in the project
+  # model and any changes or additons to these may also need to be made there.
+  def disallowed_project_visibility_level_description(level, project)
+    level_name = Gitlab::VisibilityLevel.level_name(level).downcase
+    reasons = []
+    instructions = ''
+
+    unless project.visibility_level_allowed_as_fork?(level)
+      reasons << "the fork source project has lower visibility"
+    end
+
+    unless project.visibility_level_allowed_by_group?(level)
+      errors = visibility_level_errors_for_group(project.group, level_name)
+
+      reasons << errors[:reason]
+      instructions << errors[:instruction]
+    end
+
+    reasons = reasons.any? ? ' because ' + reasons.to_sentence : ''
+    "This project cannot be #{level_name}#{reasons}.#{instructions}".html_safe
+  end
+
+  # Note: these messages closely mirror the form validation strings found in the group
+  # model and any changes or additons to these may also need to be made there.
+  def disallowed_group_visibility_level_description(level, group)
+    level_name = Gitlab::VisibilityLevel.level_name(level).downcase
+    reasons = []
+    instructions = ''
+
+    unless group.visibility_level_allowed_by_projects?(level)
+      reasons << "it contains projects with higher visibility"
+    end
+
+    unless group.visibility_level_allowed_by_sub_groups?(level)
+      reasons << "it contains sub-groups with higher visibility"
+    end
+
+    unless group.visibility_level_allowed_by_parent?(level)
+      errors = visibility_level_errors_for_group(group.parent, level_name)
+
+      reasons << errors[:reason]
+      instructions << errors[:instruction]
+    end
+
+    reasons = reasons.any? ? ' because ' + reasons.to_sentence : ''
+    "This group cannot be #{level_name}#{reasons}.#{instructions}".html_safe
+  end
+
   def visibility_icon_description(form_model)
     case form_model
     when Project
@@ -95,7 +157,18 @@ module VisibilityLevelHelper
             :default_group_visibility,
             to: :current_application_settings
 
-  def skip_level?(form_model, level)
-    form_model.is_a?(Project) && !form_model.visibility_level_allowed?(level)
+  def disallowed_visibility_level?(form_model, level)
+    return false unless form_model.respond_to?(:visibility_level_allowed?)
+    !form_model.visibility_level_allowed?(level)
+  end
+
+  private
+
+  def visibility_level_errors_for_group(group, level_name)
+    group_name = link_to group.name, group_path(group)
+    change_visiblity = link_to 'change the visibility', edit_group_path(group)
+
+    { reason: "the visibility of #{group_name} is #{group.visibility}",
+      instruction: " To make this group #{level_name}, you must first #{change_visiblity} of the parent group." }
   end
 end

app/models/group.rb

@@ -26,6 +26,8 @@ class Group < Namespace
 
   validate :avatar_type, if: ->(user) { user.avatar.present? && user.avatar_changed? }
   validate :visibility_level_allowed_by_projects
+  validate :visibility_level_allowed_by_sub_groups
+  validate :visibility_level_allowed_by_parent
 
   validates :avatar, file_size: { maximum: 200.kilobytes.to_i }
 
@@ -102,15 +104,24 @@ class Group < Namespace
     full_name
   end
 
-  def visibility_level_allowed_by_projects
-    allowed_by_projects = self.projects.where('visibility_level > ?', self.visibility_level).none?
+  def visibility_level_allowed_by_parent?(level = self.visibility_level)
+    return true unless parent_id && parent_id.nonzero?
 
-    unless allowed_by_projects
-      level_name = Gitlab::VisibilityLevel.level_name(visibility_level).downcase
-      self.errors.add(:visibility_level, "#{level_name} is not allowed since there are projects with higher visibility.")
-    end
+    level <= parent.visibility_level
+  end
+
+  def visibility_level_allowed_by_projects?(level = self.visibility_level)
+    !projects.where('visibility_level > ?', level).exists?
+  end
 
-    allowed_by_projects
+  def visibility_level_allowed_by_sub_groups?(level = self.visibility_level)
+    !children.where('visibility_level > ?', level).exists?
+  end
+
+  def visibility_level_allowed?(level = self.visibility_level)
+    visibility_level_allowed_by_parent?(level) &&
+      visibility_level_allowed_by_projects?(level) &&
+      visibility_level_allowed_by_sub_groups?(level)
   end
 
   def avatar_url(**args)
@@ -275,11 +286,29 @@ class Group < Namespace
     list_of_ids.reverse.map { |group| variables[group.id] }.compact.flatten
   end
 
-  protected
+  private
 
   def update_two_factor_requirement
     return unless require_two_factor_authentication_changed? || two_factor_grace_period_changed?
 
     users.find_each(&:update_two_factor_requirement)
   end
+
+  def visibility_level_allowed_by_parent
+    return if visibility_level_allowed_by_parent?
+
+    errors.add(:visibility_level, "#{visibility} is not allowed since the parent group has a #{parent.visibility} visibility.")
+  end
+
+  def visibility_level_allowed_by_projects
+    return if visibility_level_allowed_by_projects?
+
+    errors.add(:visibility_level, "#{visibility} is not allowed since this group contains projects with higher visibility.")
+  end
+
+  def visibility_level_allowed_by_sub_groups
+    return if visibility_level_allowed_by_sub_groups?
+
+    errors.add(:visibility_level, "#{visibility} is not allowed since there are sub-groups with higher visibility.")
+  end
 end

app/views/admin/application_settings/_form.html.haml

@@ -7,15 +7,15 @@
       = f.label :default_branch_protection, class: 'control-label col-sm-2'
       .col-sm-10
         = f.select :default_branch_protection, options_for_select(Gitlab::Access.protection_options, @application_setting.default_branch_protection), {}, class: 'form-control'
-    .form-group.project-visibility-level-holder
+    .form-group.visibility-level-setting
       = f.label :default_project_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_project_visibility, form: f, selected_level: @application_setting.default_project_visibility, form_model: Project.new)
-    .form-group.project-visibility-level-holder
+    .form-group.visibility-level-setting
       = f.label :default_snippet_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_snippet_visibility, form: f, selected_level: @application_setting.default_snippet_visibility, form_model: ProjectSnippet.new)
-    .form-group.project-visibility-level-holder
+    .form-group.visibility-level-setting
       = f.label :default_group_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_group_visibility, form: f, selected_level: @application_setting.default_group_visibility, form_model: Group.new)

app/views/projects/new.html.haml

@@ -112,7 +112,7 @@
             %span.light (optional)
           = f.text_area :description, placeholder: 'Description format',  class: "form-control", rows: 3, maxlength: 250
 
-        .form-group.project-visibility-level-holder
+        .form-group.visibility-level-setting
           = f.label :visibility_level, class: 'label-light' do
             Visibility Level
             = link_to icon('question-circle'), help_page_path("public_access/public_access"), aria: { label: 'Documentation for Visibility Level' }

app/views/shared/_visibility_level.html.haml

 - with_label = local_assigns.fetch(:with_label, true)
 
-.form-group.project-visibility-level-holder
+.form-group.visibility-level-setting
   - if with_label
     = f.label :visibility_level, class: 'control-label' do
       Visibility Level

app/views/shared/_visibility_radios.html.haml

 - Gitlab::VisibilityLevel.values.each do |level|
-  - next if skip_level?(form_model, level)
-  .radio
-    - restricted = restricted_visibility_levels.include?(level)
+  - disallowed = disallowed_visibility_level?(form_model, level)
+  - restricted = restricted_visibility_levels.include?(level)
+  - disabled = disallowed || restricted
+  .radio{ class: [('disabled' if disabled), ('restricted' if restricted)] }
     = form.label "#{model_method}_#{level}" do
-      = form.radio_button model_method, level, checked: (selected_level == level), disabled: restricted
+      = form.radio_button model_method, level, checked: (selected_level == level), disabled: disabled
       = visibility_level_icon(level)
       .option-title
         = visibility_level_label(level)
-      .option-descr
+      .option-description
         = visibility_level_description(level, form_model)
-- unless restricted_visibility_levels.empty?
-  %div
-    %span.info
-      Some visibility level settings have been restricted by the administrator.
+      .option-disabled-reason
+        - if restricted
+          = restricted_visibility_level_description(level)
+        - elsif disallowed
+          = disallowed_visibility_level_description(level, form_model)

changelogs/unreleased/31273-creating-an-project-within-an-internal-sub-group-gives-the-option-to-set-it-a-public.yml

+---
+title: Ensure correct visibility level options shown on all Project, Group, and Snippets
+  forms
+merge_request: 13442
+author:
+type: fixed

spec/controllers/projects_controller_spec.rb

@@ -7,6 +7,38 @@ describe ProjectsController do
   let(:jpg) { fixture_file_upload(Rails.root + 'spec/fixtures/rails_sample.jpg', 'image/jpg') }
   let(:txt) { fixture_file_upload(Rails.root + 'spec/fixtures/doc_sample.txt', 'text/plain') }
 
+  describe 'GET new' do
+    context 'with an authenticated user' do
+      let(:group) { create(:group) }
+
+      before do
+        sign_in(user)
+      end
+
+      context 'when namespace_id param is present' do
+        context 'when user has access to the namespace' do
+          it 'renders the template' do
+            group.add_owner(user)
+
+            get :new, namespace_id: group.id
+
+            expect(response).to have_http_status(200)
+            expect(response).to render_template('new')
+          end
+        end
+
+        context 'when user does not have access to the namespace' do
+          it 'responds with status 404' do
+            get :new, namespace_id: group.id
+
+            expect(response).to have_http_status(404)
+            expect(response).not_to render_template('new')
+          end
+        end
+      end
+    end
+  end
+
   describe 'GET index' do
     context 'as a user' do
       it 'redirects to root page' do

spec/features/projects/new_project_spec.rb

 require 'spec_helper'
 
 feature 'New project' do
+  include Select2Helper
+
   let(:user) { create(:admin) }
 
   before do
@@ -68,26 +70,10 @@ feature 'New project' do
 
         expect(namespace.text).to eq group.name
       end
-
-      context 'on validation error' do
-        before do
-          fill_in('project_path', with: 'private-group-project')
-          choose('Internal')
-          click_button('Create project')
-
-          expect(page).to have_css '.project-edit-errors .alert.alert-danger'
-        end
-
-        it 'selects the group namespace' do
-          namespace = find('#project_namespace_id option[selected]')
-
-          expect(namespace.text).to eq group.name
-        end
-      end
     end
 
     context 'with subgroup namespace' do
-      let(:group) { create(:group, :private, owner: user) }
+      let(:group) { create(:group, owner: user) }
       let(:subgroup) { create(:group, parent: group) }
 
       before do
@@ -101,6 +87,41 @@ feature 'New project' do
         expect(namespace.text).to eq subgroup.full_path
       end
     end
+
+    context 'when changing namespaces dynamically', :js do
+      let(:public_group) { create(:group, :public) }
+      let(:internal_group) { create(:group, :internal) }
+      let(:private_group) { create(:group, :private) }
+
+      before do
+        public_group.add_owner(user)
+        internal_group.add_owner(user)
+        private_group.add_owner(user)
+        visit new_project_path(namespace_id: public_group.id)
+      end
+
+      it 'enables the correct visibility options' do
+        select2(user.namespace_id, from: '#project_namespace_id')
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PRIVATE}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::INTERNAL}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PUBLIC}")).not_to be_disabled
+
+        select2(public_group.id, from: '#project_namespace_id')
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PRIVATE}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::INTERNAL}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PUBLIC}")).not_to be_disabled
+
+        select2(internal_group.id, from: '#project_namespace_id')
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PRIVATE}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::INTERNAL}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PUBLIC}")).to be_disabled
+
+        select2(private_group.id, from: '#project_namespace_id')
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PRIVATE}")).not_to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::INTERNAL}")).to be_disabled
+        expect(find("#project_visibility_level_#{Gitlab::VisibilityLevel::PUBLIC}")).to be_disabled
+      end
+    end
   end
 
   context 'Import project options' do

spec/helpers/visibility_level_helper_spec.rb

@@ -58,35 +58,82 @@ describe VisibilityLevelHelper do
     end
   end
 
-  describe "skip_level?" do
+  describe "disallowed_visibility_level?" do
     describe "forks" do
       let(:project)       { create(:project, :internal) }
       let(:fork_project)  { create(:project, forked_from_project: project) }
 
-      it "skips levels" do
-        expect(skip_level?(fork_project, Gitlab::VisibilityLevel::PUBLIC)).to be_truthy
-        expect(skip_level?(fork_project, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
-        expect(skip_level?(fork_project, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      it "disallows levels" do
+        expect(disallowed_visibility_level?(fork_project, Gitlab::VisibilityLevel::PUBLIC)).to be_truthy
+        expect(disallowed_visibility_level?(fork_project, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
+        expect(disallowed_visibility_level?(fork_project, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
       end
     end
 
     describe "non-forked project" do
       let(:project) { create(:project, :internal) }
 
-      it "skips levels" do
-        expect(skip_level?(project, Gitlab::VisibilityLevel::PUBLIC)).to be_falsey
-        expect(skip_level?(project, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
-        expect(skip_level?(project, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      it "disallows levels" do
+        expect(disallowed_visibility_level?(project, Gitlab::VisibilityLevel::PUBLIC)).to be_falsey
+        expect(disallowed_visibility_level?(project, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
+        expect(disallowed_visibility_level?(project, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
       end
     end
 
-    describe "Snippet" do
+    describe "group" do
+      let(:group) { create(:group, :internal) }
+
+      it "disallows levels" do
+        expect(disallowed_visibility_level?(group, Gitlab::VisibilityLevel::PUBLIC)).to be_falsey
+        expect(disallowed_visibility_level?(group, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
+        expect(disallowed_visibility_level?(group, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      end
+    end
+
+    describe "sub-group" do
+      let(:group) { create(:group, :private) }
+      let(:subgroup) { create(:group, :private, parent: group) }
+
+      it "disallows levels" do
+        expect(disallowed_visibility_level?(subgroup, Gitlab::VisibilityLevel::PUBLIC)).to be_truthy
+        expect(disallowed_visibility_level?(subgroup, Gitlab::VisibilityLevel::INTERNAL)).to be_truthy
+        expect(disallowed_visibility_level?(subgroup, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      end
+    end
+
+    describe "snippet" do
       let(:snippet) { create(:snippet, :internal) }
 
-      it "skips levels" do
-        expect(skip_level?(snippet, Gitlab::VisibilityLevel::PUBLIC)).to be_falsey
-        expect(skip_level?(snippet, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
-        expect(skip_level?(snippet, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      it "disallows levels" do
+        expect(disallowed_visibility_level?(snippet, Gitlab::VisibilityLevel::PUBLIC)).to be_falsey
+        expect(disallowed_visibility_level?(snippet, Gitlab::VisibilityLevel::INTERNAL)).to be_falsey
+        expect(disallowed_visibility_level?(snippet, Gitlab::VisibilityLevel::PRIVATE)).to be_falsey
+      end
+    end
+  end
+
+  describe "disallowed_visibility_level_description" do
+    let(:group) { create(:group, :internal) }
+    let!(:subgroup) { create(:group, :internal, parent: group) }
+    let!(:project) { create(:project, :internal, group: group) }
+
+    describe "project" do
+      it "provides correct description for disabled levels" do
+        expect(disallowed_visibility_level?(project, Gitlab::VisibilityLevel::PUBLIC)).to be_truthy
+        expect(strip_tags disallowed_visibility_level_description(Gitlab::VisibilityLevel::PUBLIC, project))
+          .to include "the visibility of #{project.group.name} is internal"
+      end
+    end
+
+    describe "group" do
+      it "provides correct description for disabled levels" do
+        expect(disallowed_visibility_level?(group, Gitlab::VisibilityLevel::PRIVATE)).to be_truthy
+        expect(disallowed_visibility_level_description(Gitlab::VisibilityLevel::PRIVATE, group))
+          .to include "it contains projects with higher visibility", "it contains sub-groups with higher visibility"
+
+        expect(disallowed_visibility_level?(subgroup, Gitlab::VisibilityLevel::PUBLIC)).to be_truthy
+        expect(strip_tags disallowed_visibility_level_description(Gitlab::VisibilityLevel::PUBLIC, subgroup))
+          .to include "the visibility of #{group.name} is internal"
       end
     end
   end

spec/models/group_spec.rb

@@ -84,6 +84,83 @@ describe Group do
         expect(group).not_to be_valid
       end
     end
+
+    describe '#visibility_level_allowed_by_parent' do
+      let(:parent) { create(:group, :internal) }
+      let(:sub_group) { build(:group, parent_id: parent.id) }
+
+      context 'without a parent' do
+        it 'is valid' do
+          sub_group.parent_id = nil
+
+          expect(sub_group).to be_valid
+        end
+      end
+
+      context 'with a parent' do
+        context 'when visibility of sub group is greater than the parent' do
+          it 'is invalid' do
+            sub_group.visibility_level = Gitlab::VisibilityLevel::PUBLIC
+
+            expect(sub_group).to be_invalid
+          end
+        end
+
+        context 'when visibility of sub group is lower or equal to the parent' do
+          [Gitlab::VisibilityLevel::INTERNAL, Gitlab::VisibilityLevel::PRIVATE].each do |level|
+            it 'is valid' do
+              sub_group.visibility_level = level
+
+              expect(sub_group).to be_valid
+            end
+          end
+        end
+      end
+    end
+
+    describe '#visibility_level_allowed_by_projects' do
+      let!(:internal_group) { create(:group, :internal) }
+      let!(:internal_project) { create(:project, :internal, group: internal_group) }
+
+      context 'when group has a lower visibility' do
+        it 'is invalid' do
+          internal_group.visibility_level = Gitlab::VisibilityLevel::PRIVATE
+
+          expect(internal_group).to be_invalid
+          expect(internal_group.errors[:visibility_level]).to include('private is not allowed since this group contains projects with higher visibility.')
+        end
+      end
+
+      context 'when group has a higher visibility' do
+        it 'is valid' do
+          internal_group.visibility_level = Gitlab::VisibilityLevel::PUBLIC
+
+          expect(internal_group).to be_valid
+        end
+      end
+    end
+
+    describe '#visibility_level_allowed_by_sub_groups' do
+      let!(:internal_group) { create(:group, :internal) }
+      let!(:internal_sub_group) { create(:group, :internal, parent: internal_group) }
+
+      context 'when parent group has a lower visibility' do
+        it 'is invalid' do
+          internal_group.visibility_level = Gitlab::VisibilityLevel::PRIVATE
+
+          expect(internal_group).to be_invalid
+          expect(internal_group.errors[:visibility_level]).to include('private is not allowed since there are sub-groups with higher visibility.')
+        end
+      end
+
+      context 'when parent group has a higher visibility' do
+        it 'is valid' do
+          internal_group.visibility_level = Gitlab::VisibilityLevel::PUBLIC
+
+          expect(internal_group).to be_valid
+        end
+      end
+    end
   end
 
   describe '.visible_to_user' do