Allow a member to have an access level equal to parent groupsh-allow-equal-level-in-subgroup-membership

Suppose you have this configuration:

1. Subgroup `hello/world`
2. Subgroup `hello/mergers`.
3. Project `hello/world/my-project` has invited group `hello/world` to
access protected branches.
4. The rule allows the group to merge but no one can push.
5. User `newuser` has Owner access to the parent group `hello`.

Previously, there was no way for the user `newuser` to be added to the
`hello/mergers` group since the validation only allowed a user to be
added at a higher access level.

Since membership in a subgroup confers certain access rights, such as
being able to merge or push code to protected branches, we have to
loosen the validation and allow someone to be added at an equal level
granted by the parent group.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/11323

3 files changed, 12 insertions, 2 deletions

diff --git a/spec/models/member_spec.rb b/spec/models/member_spec.rb
index c68c3ce2abe..782a84f922b 100644
--- a/spec/models/member_spec.rb
+++ b/spec/models/member_spec.rb
@@ -70,6 +70,16 @@ describe Member do
         expect(child_member).not_to be_valid
       end
 
+      # Membership in a subgroup confers certain access rights, such as being
+      # able to merge or push code to protected branches.
+      it "is valid with an equal level" do
+        child_member.access_level = GroupMember::DEVELOPER
+
+        child_member.validate
+
+        expect(child_member).to be_valid
+      end
+
       it "is valid with a higher level" do
         child_member.access_level = GroupMember::MAINTAINER
 
diff --git a/spec/requests/api/members_spec.rb b/spec/requests/api/members_spec.rb
index 79edbb301f2..48869cab4da 100644
--- a/spec/requests/api/members_spec.rb
+++ b/spec/requests/api/members_spec.rb
@@ -236,7 +236,7 @@ describe API::Members do
                params: { user_id: stranger.id, access_level: Member::REPORTER }
 
           expect(response).to have_gitlab_http_status(400)
-          expect(json_response['message']['access_level']).to eq(["should be higher than Developer inherited membership from group #{parent.name}"])
+          expect(json_response['message']['access_level']).to eq(["should be greater than or equal to Developer inherited membership from group #{parent.name}"])
         end
 
         it 'creates the member if group level is lower', :nested_groups do
diff --git a/spec/support/shared_examples/models/member_shared_examples.rb b/spec/support/shared_examples/models/member_shared_examples.rb
index 77376496854..e5375bc8280 100644
--- a/spec/support/shared_examples/models/member_shared_examples.rb
+++ b/spec/support/shared_examples/models/member_shared_examples.rb
@@ -41,7 +41,7 @@ shared_examples_for 'inherited access level as a member of entity' do
 
       member.update(access_level: Gitlab::Access::REPORTER)
 
-      expect(member.errors.full_messages).to eq(["Access level should be higher than Developer inherited membership from group #{parent_entity.name}"])
+      expect(member.errors.full_messages).to eq(["Access level should be greater than or equal to Developer inherited membership from group #{parent_entity.name}"])
     end
 
     it 'allows changing the level from a non existing member' do