Allow Member.add_user to handle access requesters

Changes include:

- Ensure Member.add_user is not called directly when not necessary
- New GroupMember.add_users_to_group to have the same abstraction level as for Project
- Refactor Member.add_user to take a source instead of an array of members
- Fix Rubocop offenses
- Always use Project#add_user instead of project.team.add_user
- Factorize users addition as members in Member.add_users_to_source
- Make access_level a keyword argument in GroupMember.add_users_to_group and ProjectMember.add_users_to_projects
- Destroy any requester before adding them as a member
- Improve the way we handle access requesters in Member.add_user
  Instead of removing the requester and creating a new member,
  we now simply accepts their access request. This way, they will
  receive a "access request granted" email.
- Fix error that was previously silently ignored
- Stop raising when access level is invalid in Member, let Rails validation do their work

Signed-off-by: Rémy Coutable <remy@rymai.me>

2 files changed, 2 insertions, 2 deletions

diff --git a/spec/finders/joined_groups_finder_spec.rb b/spec/finders/joined_groups_finder_spec.rb
index f90a8e007c8..29a47e005a6 100644
--- a/spec/finders/joined_groups_finder_spec.rb
+++ b/spec/finders/joined_groups_finder_spec.rb
@@ -43,7 +43,7 @@ describe JoinedGroupsFinder do
       context 'if profile visitor is in one of the private group projects' do
         before do
           project = create(:project, :private, group: private_group, name: 'B', path: 'B')
-          project.team.add_user(profile_visitor, Gitlab::Access::DEVELOPER)
+          project.add_user(profile_visitor, Gitlab::Access::DEVELOPER)
         end
 
         it 'shows group' do
diff --git a/spec/finders/projects_finder_spec.rb b/spec/finders/projects_finder_spec.rb
index 7a3a74335e8..13bda5f7c5a 100644
--- a/spec/finders/projects_finder_spec.rb
+++ b/spec/finders/projects_finder_spec.rb
@@ -38,7 +38,7 @@ describe ProjectsFinder do
 
       describe 'with private projects' do
         before do
-          private_project.team.add_user(user, Gitlab::Access::MASTER)
+          private_project.add_user(user, Gitlab::Access::MASTER)
         end
 
         it do