Fix a few things after the initial improvment to Members::DestroyService

app/controllers/concerns/membership_actions.rb

@@ -15,16 +15,17 @@ module MembershipActions
   end
 
   def leave
-    Members::DestroyService.new(membershipable, current_user, user_id: current_user.id).execute(:all)
+    member = Members::DestroyService.new(membershipable, current_user, user_id: current_user.id).
+      execute(:all)
 
     source_type = membershipable.class.to_s.humanize(capitalize: false)
     notice =
-      if @member.request?
+      if member.request?
         "Your access request to the #{source_type} has been withdrawn."
       else
         "You left the \"#{membershipable.human_name}\" #{source_type}."
       end
-    redirect_path = @member.request? ? @member.source : [:dashboard, membershipable.class.to_s.tableize]
+    redirect_path = member.request? ? member.source : [:dashboard, membershipable.class.to_s.tableize]
 
     redirect_to redirect_path, notice: notice
   end

app/controllers/groups/group_members_controller.rb

@@ -40,7 +40,7 @@ class Groups::GroupMembersController < Groups::ApplicationController
   end
 
   def destroy
-    Members::DestroyService.new(@group, current_user, user_id: params[:id]).execute(:all)
+    Members::DestroyService.new(@group, current_user, id: params[:id]).execute(:all)
 
     respond_to do |format|
       format.html { redirect_to group_group_members_path(@group), notice: 'User was successfully removed from group.' }

app/controllers/projects/project_members_controller.rb

@@ -55,7 +55,8 @@ class Projects::ProjectMembersController < Projects::ApplicationController
   end
 
   def destroy
-    Members::DestroyService.new(@project, current_user, user_id: params[:id]).execute(:all)
+    Members::DestroyService.new(@project, current_user, params).
+      execute(:all)
 
     respond_to do |format|
       format.html do

app/services/members/authorized_destroy_service.rb

@@ -14,6 +14,8 @@ module Members
       if member.request? && member.user != user
         notification_service.decline_access_request(member)
       end
+
+      member
     end
   end
 end

app/services/members/destroy_service.rb

@@ -15,7 +15,7 @@ module Members
     def execute(scope = :members)
       raise "scope :#{scope} is not allowed!" unless ALLOWED_SCOPES.include?(scope)
 
-      member = find_member(scope)
+      member = find_member!(scope)
 
       raise Gitlab::Access::AccessDeniedError if cannot_destroy_member?(member)
 
@@ -24,13 +24,14 @@ module Members
 
     private
 
-    def find_member(scope)
+    def find_member!(scope)
+      condition = params[:user_id] ? { user_id: params[:user_id] } : { id: params[:id] }
       case scope
       when :all
-        source.members.find_by(user_id: params[:user_id]) ||
-          source.requesters.find_by!(user_id: params[:user_id])
+        source.members.find_by(condition) ||
+          source.requesters.find_by!(condition)
       else
-        source.public_send(scope).find_by!(user_id: params[:user_id])
+        source.public_send(scope).find_by!(condition)
       end
     end
 

lib/api/access_requests.rb

@@ -75,7 +75,8 @@ module API
           required_attributes! [:user_id]
           source = find_source(source_type, params[:id])
 
-          ::Members::DestroyService.new(source, current_user, declared(params)).execute(:requesters)
+          ::Members::DestroyService.new(source, current_user, params).
+            execute(:requesters)
         end
       end
     end

spec/controllers/groups/group_members_controller_spec.rb

@@ -87,10 +87,10 @@ describe Groups::GroupMembersController do
     context 'when member is not found' do
       before { sign_in(user) }
 
-      it 'returns 403' do
+      it 'returns 404' do
         delete :leave, group_id: group
 
-        expect(response).to have_http_status(403)
+        expect(response).to have_http_status(404)
       end
     end
 

spec/controllers/projects/project_members_controller_spec.rb

@@ -135,11 +135,11 @@ describe Projects::ProjectMembersController do
     context 'when member is not found' do
       before { sign_in(user) }
 
-      it 'returns 403' do
+      it 'returns 404' do
         delete :leave, namespace_id: project.namespace,
                        project_id: project
 
-        expect(response).to have_http_status(403)
+        expect(response).to have_http_status(404)
       end
     end
 

spec/services/members/destroy_service_spec.rb

@@ -98,6 +98,15 @@ describe Members::DestroyService, services: true do
       it_behaves_like 'a service destroying a member' do
         let(:source) { group }
       end
+
+      context 'when given a :id' do
+        let(:params) { { id: project.members.find_by!(user_id: user.id).id } }
+
+        it 'destroys the member' do
+          expect { described_class.new(project, user, params).execute }.
+            to change { project.members.count }.by(-1)
+        end
+      end
     end
   end
 end