Expose boolean predicate methods in API

changelogs/unreleased/290254-override-approvers-setting-does-not-reflect-actual-behavior.yml

+---
+title: Ensure Project Approvals API casts to boolean
+merge_request: 55492
+author:
+type: fixed

ee/lib/ee/api/entities/approval_settings.rb

@@ -7,11 +7,20 @@ module EE
         expose :approvers, using: EE::API::Entities::Approver
         expose :approver_groups, using: EE::API::Entities::ApproverGroup
         expose :approvals_before_merge
+
         expose :reset_approvals_on_push
-        expose :disable_overriding_approvers_per_merge_request
-        expose :merge_requests_author_approval
-        expose :merge_requests_disable_committers_approval
-        expose :require_password_to_approve
+
+        expose :disable_overriding_approvers_per_merge_request?,
+          as: :disable_overriding_approvers_per_merge_request
+
+        expose :merge_requests_author_approval?,
+          as: :merge_requests_author_approval
+
+        expose :merge_requests_disable_committers_approval?,
+          as: :merge_requests_disable_committers_approval
+
+        expose :require_password_to_approve?,
+          as: :require_password_to_approve
       end
     end
   end

ee/spec/requests/api/project_approvals_spec.rb

@@ -20,6 +20,18 @@ RSpec.describe API::ProjectApprovals do
         get api(url, user)
       end
 
+      it 'does not return null values for unmodified boolean fields' do
+        expect(project.disable_overriding_approvers_per_merge_request).to be_nil
+        expect(project.merge_requests_author_approval).to be_nil
+        expect(project.merge_requests_disable_committers_approval).to be_nil
+        expect(project.require_password_to_approve).to be_nil
+
+        expect(json_response["disable_overriding_approvers_per_merge_request"]).to be false
+        expect(json_response["merge_requests_author_approval"]).to be false
+        expect(json_response["merge_requests_disable_committers_approval"]).to be false
+        expect(json_response["require_password_to_approve"]).to be false
+      end
+
       it 'returns 200 status' do
         expect(response).to have_gitlab_http_status(:ok)
       end