Use `Gitlab::Access` to protected branch access levels.

1. It makes sense to reuse these constants since we had them duplicated
   in the previous enum implementation. This also simplifies our
   `check_access` implementation, because we can use
   `project.team.max_member_access` directly.

2. Use `accepts_nested_attributes_for` to create push/merge access
   levels. This was a bit fiddly to set up, but this simplifies our code
   by quite a large amount. We can even get rid of
   `ProtectedBranches::BaseService`.

3. Move API handling back into the API (previously in
   `ProtectedBranches::BaseService#translate_api_params`.

4. The protected branch services now return a `ProtectedBranch` rather
   than `true/false`.

5. Run `load_protected_branches` on-demand in the `create` action, to
   prevent it being called unneccessarily.

6. "Masters" is pre-selected as the default option for "Allowed to Push"
   and "Allowed to Merge".

7. These changes were based on a review from @rymai in !5081.

1 files changed, 6 insertions, 6 deletions

diff --git a/spec/services/git_push_service_spec.rb b/spec/services/git_push_service_spec.rb
index 621eced83f6..ffa998dffc3 100644
--- a/spec/services/git_push_service_spec.rb
+++ b/spec/services/git_push_service_spec.rb
@@ -227,8 +227,8 @@ describe GitPushService, services: true do
         expect(project.default_branch).to eq("master")
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.first.allowed_to_push).to eq('masters')
-        expect(project.protected_branches.first.allowed_to_merge).to eq('masters')
+        expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.first.merge_access_level.access_level).to eq(Gitlab::Access::MASTER)
       end
 
       it "when pushing a branch for the first time with default branch protection disabled" do
@@ -249,8 +249,8 @@ describe GitPushService, services: true do
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
 
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.last.allowed_to_push).to eq('developers')
-        expect(project.protected_branches.last.allowed_to_merge).to eq('masters')
+        expect(project.protected_branches.last.push_access_level.access_level).to eq(Gitlab::Access::DEVELOPER)
+        expect(project.protected_branches.last.merge_access_level.access_level).to eq(Gitlab::Access::MASTER)
       end
 
       it "when pushing a branch for the first time with default branch protection set to 'developers can merge'" do
@@ -260,8 +260,8 @@ describe GitPushService, services: true do
         expect(project.default_branch).to eq("master")
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.first.allowed_to_push).to eq('masters')
-        expect(project.protected_branches.first.allowed_to_merge).to eq('developers')
+        expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.first.merge_access_level.access_level).to eq(Gitlab::Access::DEVELOPER)
       end
 
       it "when pushing new commits to existing branch" do