Add self approval of merge requests setting to Merge Request Approvals API

ee/changelogs/unreleased/9496-add-enable-self-approval-of-merge-requests-setting-to-merge-request-approvals-api.yml

+---
+title: Add self approval of merge requests setting to merge requests approvals API
+merge_request: 10050
+author:
+type: changed

ee/lib/api/project_approvals.rb

@@ -28,7 +28,8 @@ module API
           optional :approvals_before_merge, type: Integer, desc: 'The amount of approvals required before an MR can be merged'
           optional :reset_approvals_on_push, type: Boolean, desc: 'Should the approval count be reset on a new push'
           optional :disable_overriding_approvers_per_merge_request, type: Boolean, desc: 'Should MRs be able to override approvers and approval count'
-          at_least_one_of :approvals_before_merge, :reset_approvals_on_push, :disable_overriding_approvers_per_merge_request
+          optional :merge_requests_author_approval, type: Boolean, desc: 'Should authors be able to self approve merge requests'
+          at_least_one_of :approvals_before_merge, :reset_approvals_on_push, :disable_overriding_approvers_per_merge_request, :merge_requests_author_approval
         end
         post '/' do
           project_params = declared(params, include_missing: false, include_parent_namespaces: false)

ee/lib/ee/api/entities.rb

@@ -324,6 +324,7 @@ module EE
         expose :approvals_before_merge
         expose :reset_approvals_on_push
         expose :disable_overriding_approvers_per_merge_request
+        expose :merge_requests_author_approval
       end
 
       class Approvals < Grape::Entity

ee/spec/fixtures/api/schemas/public_api/v4/project_approvers.json

@@ -4,6 +4,7 @@
     "approvals_before_merge": { "type": "integer" },
     "disable_overriding_approvers_per_merge_request": { "type": ["boolean", "null"] },
     "reset_approvals_on_push": { "type": "boolean" },
+    "merge_requests_author_approval": { "type": ["boolean", "null"] },
     "approvers": {
       "type": "array",
       "items": {

ee/spec/requests/api/project_approvals_spec.rb

@@ -70,12 +70,14 @@ describe API::ProjectApprovals do
           project.approvals_before_merge = 2
           project.reset_approvals_on_push = false
           project.disable_overriding_approvers_per_merge_request = true
+          project.merge_requests_author_approval = false
           project.save
 
           settings = {
             approvals_before_merge: 4,
             reset_approvals_on_push: true,
-            disable_overriding_approvers_per_merge_request: false
+            disable_overriding_approvers_per_merge_request: false,
+            merge_requests_author_approval: true
           }
 
           post api(url, current_user), params: settings