API to delete group push rule

Adds ability for group owners and admins
to delete push rules for a group.

doc/api/groups.md

@@ -1170,10 +1170,14 @@ DELETE /groups/:id/share/:group_id
 
 ## Push Rules **(STARTER)**
 
+> Introduced in [GitLab Starter](https://about.gitlab.com/pricing/) 13.4.
+
 ### Get group push rules **(STARTER)**
 
 Get the [push rules](../user/group/index.md#group-push-rules-starter) of a group.
 
+Only available to group owners and administrators.
+
 ```plaintext
 GET /groups/:id/push_rule
 ```
@@ -1215,6 +1219,8 @@ the `commit_committer_check` and `reject_unsigned_commits` parameters:
 
 Adds [push rules](../user/group/index.md#group-push-rules-starter) to the specified group.
 
+Only available to group owners and administrators.
+
 ```plaintext
 POST /groups/:id/push_rule
 ```
@@ -1260,6 +1266,8 @@ Response:
 
 Edit push rules for a specified group.
 
+Only available to group owners and administrators.
+
 ```plaintext
 PUT /groups/:id/push_rule
 ```
@@ -1300,3 +1308,17 @@ Response:
     "max_file_size": 100
 }
 ```
+
+### Delete group push rule **(STARTER)**
+
+Deletes the [push rules](../user/group/index.md#group-push-rules-starter) of a group.
+
+Only available to group owners and administrators.
+
+```plaintext
+DELETE /groups/:id/push_rule
+```
+
+| Attribute | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |

ee/changelogs/unreleased/delete_group_push_rule.yml

+---
+title: API to delete group push rule
+merge_request: 40293
+author:
+type: added

ee/lib/api/group_push_rule.rb

@@ -3,8 +3,7 @@
 module API
   class GroupPushRule < Grape::API::Instance
     before { authenticate! }
-    before { authorize_admin_group }
-    before { check_feature_availability! }
+    before { check_group_push_rule_access! }
     before { authorize_change_param(user_group, :commit_committer_check, :reject_unsigned_commits) }
 
     params do
@@ -13,8 +12,8 @@ module API
 
     resource :groups do
       helpers do
-        def check_feature_availability!
-          not_found! unless user_group.feature_available?(:push_rules)
+        def check_group_push_rule_access!
+          not_found! unless can?(current_user, :change_push_rules, user_group)
         end
 
         params :push_rule_params do
@@ -82,6 +81,16 @@ module API
           render_validation_error!(push_rule)
         end
       end
+
+      desc 'Deletes group push rule' do
+        detail 'This feature was introduced in GitLab 13.4.'
+      end
+      delete ":id/push_rule" do
+        push_rule = user_group.push_rule
+        not_found! unless push_rule
+
+        destroy_conditionally!(push_rule)
+      end
     end
   end
 end

ee/spec/requests/api/group_push_rule_spec.rb

@@ -77,19 +77,19 @@ RSpec.describe API::GroupPushRule, 'GroupPushRule', api: true do
 
           expect(json_response).to eq(
             {
-             "author_email_regex" => attributes[:author_email_regex],
-             "branch_name_regex" => nil,
-             "commit_committer_check" => true,
-             "commit_message_negative_regex" => attributes[:commit_message_negative_regex],
-             "commit_message_regex" => attributes[:commit_message_regex],
-             "created_at" => group.reload.push_rule.created_at.iso8601(3),
-             "deny_delete_tag" => false,
-             "file_name_regex" => nil,
-             "id" => group.push_rule.id,
-             "max_file_size" => 100,
-             "member_check" => false,
-             "prevent_secrets" => true,
-             "reject_unsigned_commits" => true
+              "author_email_regex" => attributes[:author_email_regex],
+              "branch_name_regex" => nil,
+              "commit_committer_check" => true,
+              "commit_message_negative_regex" => attributes[:commit_message_negative_regex],
+              "commit_message_regex" => attributes[:commit_message_regex],
+              "created_at" => group.reload.push_rule.created_at.iso8601(3),
+              "deny_delete_tag" => false,
+              "file_name_regex" => nil,
+              "id" => group.push_rule.id,
+              "max_file_size" => 100,
+              "member_check" => false,
+              "prevent_secrets" => true,
+              "reject_unsigned_commits" => true
             }
           )
         end
@@ -292,8 +292,8 @@ RSpec.describe API::GroupPushRule, 'GroupPushRule', api: true do
 
         it 'updates attributes as expected' do
           expect { subject }.to change { group.reload.push_rule.author_email_regex }
-                               .from(attributes[:author_email_regex])
-                               .to(attributes_for_update[:author_email_regex])
+                                  .from(attributes[:author_email_regex])
+                                  .to(attributes_for_update[:author_email_regex])
         end
 
         context 'when push rule does not exist for group' do
@@ -366,4 +366,46 @@ RSpec.describe API::GroupPushRule, 'GroupPushRule', api: true do
       end
     end
   end
+
+  describe 'DELETE /groups/:id/push_rule' do
+    let_it_be(:push_rule) { create(:push_rule, **attributes) }
+    let_it_be(:group) { create(:group, push_rule: push_rule) }
+
+    context 'authorized user' do
+      context 'when licensed' do
+        include_context 'licensed features available'
+
+        context 'with group push rule' do
+          it do
+            delete api("/groups/#{group.id}/push_rule", admin)
+
+            expect(response).to have_gitlab_http_status(:no_content)
+            expect(group.reload.push_rule).to be nil
+          end
+        end
+
+        context 'when push rule does not exist' do
+          it 'returns not found' do
+            no_push_rule_group = create(:group)
+
+            delete api("/groups/#{no_push_rule_group.id}/push_rule", admin)
+
+            expect(response).to have_gitlab_http_status(:not_found)
+          end
+        end
+      end
+
+      context 'when unlicensed' do
+        subject { delete api("/groups/#{group.id}/push_rule", admin) }
+
+        it_behaves_like 'not found when feature is unavailable'
+      end
+    end
+
+    context 'permissions' do
+      subject { delete api("/groups/#{group.id}/push_rule", user) }
+
+      it_behaves_like 'allow access to api based on role'
+    end
+  end
 end