Tidy up the specs for merge request approval api requests

MR: gitlab.com/gitlab-org/gitlab/-/merge_requests/83501
Issue: gitlab.com/gitlab-org/gitlab/-/issues/356248

ee/spec/requests/api/merge_request_approval_rules_spec.rb

@@ -49,10 +49,26 @@ RSpec.describe API::MergeRequestApprovalRules do
     end
   end
 
-  describe 'GET /projects/:id/merge_requests/:merge_request_iid/approval_rules' do
+  shared_context 'getting approval rule' do
+    let(:approver) { create(:user) }
+    let(:group) { create(:group) }
+    let(:source_rule) { nil }
+    let(:users) { [approver] }
+    let(:groups) { [group] }
     let(:current_user) { other_user }
-    let(:url) { "/projects/#{project.id}/merge_requests/#{merge_request.iid}/approval_rules" }
 
+    let!(:mr_approval_rule) do
+      create(
+        :approval_merge_request_rule,
+        merge_request: merge_request,
+        approval_project_rule: source_rule,
+        users: users,
+        groups: groups
+      )
+    end
+  end
+
+  shared_examples_for 'getting approval rule/s' do
     context 'user cannot read merge request' do
       before do
         project.project_feature.update!(merge_requests_access_level: ProjectFeature::PRIVATE)
@@ -66,22 +82,6 @@ RSpec.describe API::MergeRequestApprovalRules do
     end
 
     context 'use can read merge request' do
-      let(:approver) { create(:user) }
-      let(:group) { create(:group) }
-      let(:source_rule) { nil }
-      let(:users) { [approver] }
-      let(:groups) { [group] }
-
-      let!(:mr_approval_rule) do
-        create(
-          :approval_merge_request_rule,
-          merge_request: merge_request,
-          approval_project_rule: source_rule,
-          users: users,
-          groups: groups
-        )
-      end
-
       before do
         group.add_developer(approver)
         merge_request.approvals.create!(user: approver)
@@ -91,20 +91,19 @@ RSpec.describe API::MergeRequestApprovalRules do
 
       it 'matches the response schema' do
         expect(response).to have_gitlab_http_status(:ok)
-        expect(response).to match_response_schema('public_api/v4/merge_request_approval_rules', dir: 'ee')
+        expect(response).to match_response_schema(schema_path, dir: 'ee')
 
-        rules = json_response
+        rule = get_rule.call(json_response)
 
-        expect(rules.size).to eq(1)
-        expect(rules.first['name']).to eq(mr_approval_rule.name)
-        expect(rules.first['approvals_required']).to eq(mr_approval_rule.approvals_required)
-        expect(rules.first['rule_type']).to eq(mr_approval_rule.rule_type)
-        expect(rules.first['section']).to be_nil
-        expect(rules.first['contains_hidden_groups']).to eq(false)
-        expect(rules.first['source_rule']).to be_nil
-        expect(rules.first['eligible_approvers']).to match([hash_including('id' => approver.id)])
-        expect(rules.first['users']).to match([hash_including('id' => approver.id)])
-        expect(rules.first['groups']).to match([hash_including('id' => group.id)])
+        expect(rule['name']).to eq(mr_approval_rule.name)
+        expect(rule['approvals_required']).to eq(mr_approval_rule.approvals_required)
+        expect(rule['rule_type']).to eq(mr_approval_rule.rule_type)
+        expect(rule['section']).to be_nil
+        expect(rule['contains_hidden_groups']).to eq(false)
+        expect(rule['source_rule']).to be_nil
+        expect(rule['eligible_approvers']).to match_array([hash_including('id' => approver.id)])
+        expect(rule['users']).to match_array([hash_including('id' => approver.id)])
+        expect(rule['groups']).to match_array([hash_including('id' => group.id)])
       end
 
       context 'groups contain private groups' do
@@ -112,10 +111,10 @@ RSpec.describe API::MergeRequestApprovalRules do
 
         context 'current_user cannot see private group' do
           it 'hides private group' do
-            rules = json_response
+            rule = get_rule.call(json_response)
 
-            expect(rules.first['contains_hidden_groups']).to eq(true)
-            expect(rules.first['groups']).to be_empty
+            expect(rule['contains_hidden_groups']).to eq(true)
+            expect(rule['groups']).to be_empty
           end
         end
 
@@ -123,10 +122,10 @@ RSpec.describe API::MergeRequestApprovalRules do
           let(:current_user) { approver }
 
           it 'shows private group' do
-            rules = json_response
+            rule = get_rule.call(json_response)
 
-            expect(rules.first['contains_hidden_groups']).to eq(false)
-            expect(rules.first['groups']).to match([hash_including('id' => group.id)])
+            expect(rule['contains_hidden_groups']).to eq(false)
+            expect(rule['groups']).to match_array([hash_including('id' => group.id)])
           end
         end
       end
@@ -135,46 +134,34 @@ RSpec.describe API::MergeRequestApprovalRules do
         let(:source_rule) { create(:approval_project_rule, project: project) }
 
         it 'includes source_rule' do
-          expect(json_response.first['source_rule']['approvals_required']).to eq(source_rule.approvals_required)
+          rule = get_rule.call(json_response)
+
+          expect(rule['source_rule']['approvals_required']).to eq(source_rule.approvals_required)
         end
       end
     end
   end
 
   describe 'GET /projects/:id/merge_requests/:merge_request_iid/approval_rules/:approval_rule_id' do
-    let(:current_user) { other_user }
-    let(:approver) { create(:user) }
-    let(:group) { create(:group) }
-    let(:source_rule) { nil }
-    let(:users) { [approver] }
-    let(:groups) { [group] }
+    include_context "getting approval rule"
 
-    let(:approval_rule) do
-      create(
-        :approval_merge_request_rule,
-        merge_request: merge_request,
-        approval_project_rule: source_rule,
-        approvals_required: 2,
-        users: users,
-        groups: groups
-      )
-    end
+    let(:url) { "/projects/#{project.id}/merge_requests/#{merge_request.iid}/approval_rules/#{mr_approval_rule.id}" }
+    let(:schema_path) { 'public_api/v4/merge_request_approval_rule' }
+    let(:get_rule) { -> (response) { response } }
 
-    let(:url) { "/projects/#{project.id}/merge_requests/#{merge_request.iid}/approval_rules/#{approval_rule.id}" }
+    it_behaves_like 'getting approval rule/s'
+  end
 
-    context 'user cannot read merge request' do
-      before do
-        project.project_feature.update!(merge_requests_access_level: ProjectFeature::PRIVATE)
+  describe 'GET /projects/:id/merge_requests/:merge_request_iid/approval_rules' do
+    include_context "getting approval rule"
 
-        get api(url, other_user)
-      end
+    let(:url) { "/projects/#{project.id}/merge_requests/#{merge_request.iid}/approval_rules" }
+    let(:schema_path) { 'public_api/v4/merge_request_approval_rules' }
+    let(:get_rule) { -> (response) { response.first } }
 
-      it 'responds with 403' do
-        expect(response).to have_gitlab_http_status(:forbidden)
-      end
-    end
+    it_behaves_like 'getting approval rule/s'
 
-    context 'user can read merge request' do
+    context 'use can read merge request' do
       before do
         group.add_developer(approver)
         merge_request.approvals.create!(user: approver)
@@ -182,47 +169,10 @@ RSpec.describe API::MergeRequestApprovalRules do
         get api(url, current_user)
       end
 
-      it 'matches the response schema' do
-        expect(response).to have_gitlab_http_status(:ok)
-        expect(response).to match_response_schema('public_api/v4/merge_request_approval_rule', dir: 'ee')
-
-        expect(json_response['name']).to eq(approval_rule.name)
-        expect(json_response['approvals_required']).to eq(approval_rule.approvals_required)
-        expect(json_response['rule_type']).to eq(approval_rule.rule_type)
-        expect(json_response['section']).to be_nil
-        expect(json_response['contains_hidden_groups']).to eq(false)
-        expect(json_response['source_rule']).to be_nil
-        expect(json_response['eligible_approvers']).to match_array([hash_including('id' => approver.id)])
-        expect(json_response['users']).to match_array([hash_including('id' => approver.id)])
-        expect(json_response['groups']).to match_array([hash_including('id' => group.id)])
-      end
-
-      context 'groups contain private groups' do
-        let(:group) { create(:group, :private) }
-
-        context 'current_user cannot see private group' do
-          it 'hides private group' do
-            expect(json_response['contains_hidden_groups']).to eq(true)
-            expect(json_response['groups']).to be_empty
-          end
-        end
-
-        context 'current_user can see private group' do
-          let(:current_user) { approver }
-
-          it 'shows private group' do
-            expect(json_response['contains_hidden_groups']).to eq(false)
-            expect(json_response['groups']).to match_array([hash_including('id' => group.id)])
-          end
-        end
-      end
-
-      context 'has existing merge request rule that overrides a project-level rule' do
-        let(:source_rule) { create(:approval_project_rule, project: project) }
+      it 'returns the correct amount of rules' do
+        rules = json_response
 
-        it 'includes source_rule' do
-          expect(json_response['source_rule']['approvals_required']).to eq(source_rule.approvals_required)
-        end
+        expect(rules.size).to eq(1)
       end
     end
   end