Allow creating epic board lists

Adds mutation and service for creating epic board lists.  Because most
of the functionality is same as for issue boar lists, it also moves
shared logic into a parent class.

app/graphql/mutations/boards/lists/base_create.rb

+# frozen_string_literal: true
+
+module Mutations
+  module Boards
+    module Lists
+      class BaseCreate < BaseMutation
+        argument :backlog, GraphQL::BOOLEAN_TYPE,
+                 required: false,
+                 description: 'Create the backlog list.'
+
+        argument :label_id, ::Types::GlobalIDType[::Label],
+                 required: false,
+                 description: 'Global ID of an existing label.'
+
+        def ready?(**args)
+          if args.slice(*mutually_exclusive_args).size != 1
+            arg_str = mutually_exclusive_args.map { |x| x.to_s.camelize(:lower) }.join(' or ')
+            raise Gitlab::Graphql::Errors::ArgumentError, "one and only one of #{arg_str} is required"
+          end
+
+          super
+        end
+
+        def resolve(**args)
+          board  = authorized_find!(id: args[:board_id])
+          params = create_list_params(args)
+
+          response = create_list(board, params)
+
+          {
+            list: response.success? ? response.payload[:list] : nil,
+            errors: response.errors
+          }
+        end
+
+        private
+
+        def create_list(board, params)
+          raise NotImplementedError
+        end
+
+        def create_list_params(args)
+          params = args.slice(*mutually_exclusive_args).with_indifferent_access
+          params[:label_id] &&= ::GitlabSchema.parse_gid(params[:label_id], expected_type: ::Label).model_id
+
+          params
+        end
+
+        def mutually_exclusive_args
+          [:backlog, :label_id]
+        end
+      end
+    end
+  end
+end

app/graphql/mutations/boards/lists/create.rb

@@ -3,59 +3,32 @@
 module Mutations
   module Boards
     module Lists
-      class Create < Base
+      class Create < BaseCreate
         graphql_name 'BoardListCreate'
 
-        argument :backlog, GraphQL::BOOLEAN_TYPE,
-                 required: false,
-                 description: 'Create the backlog list.'
+        argument :board_id, ::Types::GlobalIDType[::Board],
+                 required: true,
+                 description: 'Global ID of the issue board to mutate.'
 
-        argument :label_id, ::Types::GlobalIDType[::Label],
-                 required: false,
-                 description: 'Global ID of an existing label.'
+        field :list,
+              Types::BoardListType,
+              null: true,
+              description: 'Issue list in the issue board.'
 
-        def ready?(**args)
-          if args.slice(*mutually_exclusive_args).size != 1
-            arg_str = mutually_exclusive_args.map { |x| x.to_s.camelize(:lower) }.join(' or ')
-            raise Gitlab::Graphql::Errors::ArgumentError, "one and only one of #{arg_str} is required"
-          end
-
-          super
-        end
+        authorize :admin_list
 
-        def resolve(**args)
-          board  = authorized_find!(id: args[:board_id])
-          params = create_list_params(args)
-
-          response = create_list(board, params)
+        private
 
-          {
-            list: response.success? ? response.payload[:list] : nil,
-            errors: response.errors
-          }
+        def find_object(id:)
+          GitlabSchema.object_from_id(id, expected_type: ::Board)
         end
 
-        private
-
         def create_list(board, params)
           create_list_service =
             ::Boards::Lists::CreateService.new(board.resource_parent, current_user, params)
 
           create_list_service.execute(board)
         end
-
-        # Overridden in EE
-        def create_list_params(args)
-          params = args.slice(*mutually_exclusive_args).with_indifferent_access
-          params[:label_id] &&= ::GitlabSchema.parse_gid(params[:label_id], expected_type: ::Label).model_id
-
-          params
-        end
-
-        # Overridden in EE
-        def mutually_exclusive_args
-          [:backlog, :label_id]
-        end
       end
     end
   end

app/services/boards/lists/base_create_service.rb

+# frozen_string_literal: true
+
+module Boards
+  module Lists
+    # This class is used by issue and epic board lists
+    # for creating new list
+    class BaseCreateService < Boards::BaseService
+      include Gitlab::Utils::StrongMemoize
+
+      def execute(board)
+        list = case type
+               when :backlog
+                 create_backlog(board)
+               else
+                 target = target(board)
+                 position = next_position(board)
+
+                 return ServiceResponse.error(message: _('%{board_target} not found') % { board_target: type.to_s.capitalize }) if target.blank?
+
+                 create_list(board, type, target, position)
+               end
+
+        return ServiceResponse.error(message: list.errors.full_messages) unless list.persisted?
+
+        ServiceResponse.success(payload: { list: list })
+      end
+
+      private
+
+      def type
+        # We don't ever expect to have more than one list
+        # type param at once.
+        if params.key?('backlog')
+          :backlog
+        else
+          :label
+        end
+      end
+
+      def target(board)
+        strong_memoize(:target) do
+          available_labels.find_by(id: params[:label_id]) # rubocop: disable CodeReuse/ActiveRecord
+        end
+      end
+
+      def available_labels
+        ::Labels::AvailableLabelsService.new(current_user, parent, {})
+          .available_labels
+      end
+
+      def next_position(board)
+        max_position = board.lists.movable.maximum(:position)
+        max_position.nil? ? 0 : max_position.succ
+      end
+
+      def create_list(board, type, target, position)
+        board.lists.create(create_list_attributes(type, target, position))
+      end
+
+      def create_list_attributes(type, target, position)
+        { type => target, list_type: type, position: position }
+      end
+
+      def create_backlog(board)
+        return board.lists.backlog.first if board.lists.backlog.exists?
+
+        board.lists.create(list_type: :backlog, position: nil)
+      end
+    end
+  end
+end

app/services/boards/lists/create_service.rb

@@ -2,68 +2,7 @@
 
 module Boards
   module Lists
-    class CreateService < Boards::BaseService
-      include Gitlab::Utils::StrongMemoize
-
-      def execute(board)
-        list = case type
-               when :backlog
-                 create_backlog(board)
-               else
-                 target = target(board)
-                 position = next_position(board)
-
-                 return ServiceResponse.error(message: _('%{board_target} not found') % { board_target: type.to_s.capitalize }) if target.blank?
-
-                 create_list(board, type, target, position)
-               end
-
-        return ServiceResponse.error(message: list.errors.full_messages) unless list.persisted?
-
-        ServiceResponse.success(payload: { list: list })
-      end
-
-      private
-
-      def type
-        # We don't ever expect to have more than one list
-        # type param at once.
-        if params.key?('backlog')
-          :backlog
-        else
-          :label
-        end
-      end
-
-      def target(board)
-        strong_memoize(:target) do
-          available_labels.find_by(id: params[:label_id]) # rubocop: disable CodeReuse/ActiveRecord
-        end
-      end
-
-      def available_labels
-        ::Labels::AvailableLabelsService.new(current_user, parent, {})
-          .available_labels
-      end
-
-      def next_position(board)
-        max_position = board.lists.movable.maximum(:position)
-        max_position.nil? ? 0 : max_position.succ
-      end
-
-      def create_list(board, type, target, position)
-        board.lists.create(create_list_attributes(type, target, position))
-      end
-
-      def create_list_attributes(type, target, position)
-        { type => target, list_type: type, position: position }
-      end
-
-      def create_backlog(board)
-        return board.lists.backlog.first if board.lists.backlog.exists?
-
-        board.lists.create(list_type: :backlog, position: nil)
-      end
+    class CreateService < Boards::Lists::BaseCreateService
     end
   end
 end

doc/api/graphql/reference/gitlab_schema.graphql

@@ -2361,7 +2361,7 @@ type BoardListCreatePayload {
   errors: [String!]!
 
   """
-  List of the issue board.
+  Issue list in the issue board.
   """
   list: BoardList
 }
@@ -9155,6 +9155,51 @@ type EpicBoardEdge {
   node: EpicBoard
 }
 
+"""
+Autogenerated input type of EpicBoardListCreate
+"""
+input EpicBoardListCreateInput {
+  """
+  Create the backlog list.
+  """
+  backlog: Boolean
+
+  """
+  Global ID of the issue board to mutate.
+  """
+  boardId: BoardsEpicBoardID!
+
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Global ID of an existing label.
+  """
+  labelId: LabelID
+}
+
+"""
+Autogenerated return type of EpicBoardListCreate
+"""
+type EpicBoardListCreatePayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Errors encountered during execution of the mutation.
+  """
+  errors: [String!]!
+
+  """
+  Epic list in the epic board.
+  """
+  list: EpicList
+}
+
 """
 The connection type for Epic.
 """
@@ -16235,6 +16280,7 @@ type Mutation {
   environmentsCanaryIngressUpdate(input: EnvironmentsCanaryIngressUpdateInput!): EnvironmentsCanaryIngressUpdatePayload
   epicAddIssue(input: EpicAddIssueInput!): EpicAddIssuePayload
   epicBoardCreate(input: EpicBoardCreateInput!): EpicBoardCreatePayload
+  epicBoardListCreate(input: EpicBoardListCreateInput!): EpicBoardListCreatePayload
   epicSetSubscription(input: EpicSetSubscriptionInput!): EpicSetSubscriptionPayload
   epicTreeReorder(input: EpicTreeReorderInput!): EpicTreeReorderPayload
   exportRequirements(input: ExportRequirementsInput!): ExportRequirementsPayload

doc/api/graphql/reference/gitlab_schema.json

@@ -6046,36 +6046,36 @@
           "fields": null,
           "inputFields": [
             {
-              "name": "boardId",
-              "description": "Global ID of the issue board to mutate.",
+              "name": "backlog",
+              "description": "Create the backlog list.",
               "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
                 "kind": "SCALAR",
-                  "name": "BoardID",
+                "name": "Boolean",
                 "ofType": null
-                }
               },
               "defaultValue": null
             },
             {
-              "name": "backlog",
-              "description": "Create the backlog list.",
+              "name": "labelId",
+              "description": "Global ID of an existing label.",
               "type": {
                 "kind": "SCALAR",
-                "name": "Boolean",
+                "name": "LabelID",
                 "ofType": null
               },
               "defaultValue": null
             },
             {
-              "name": "labelId",
-              "description": "Global ID of an existing label.",
+              "name": "boardId",
+              "description": "Global ID of the issue board to mutate.",
               "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
                   "kind": "SCALAR",
-                "name": "LabelID",
+                  "name": "BoardID",
                   "ofType": null
+                }
               },
               "defaultValue": null
             },
@@ -6171,7 +6171,7 @@
             },
             {
               "name": "list",
-              "description": "List of the issue board.",
+              "description": "Issue list in the issue board.",
               "args": [
 
               ],
@@ -25291,6 +25291,128 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "INPUT_OBJECT",
+          "name": "EpicBoardListCreateInput",
+          "description": "Autogenerated input type of EpicBoardListCreate",
+          "fields": null,
+          "inputFields": [
+            {
+              "name": "backlog",
+              "description": "Create the backlog list.",
+              "type": {
+                "kind": "SCALAR",
+                "name": "Boolean",
+                "ofType": null
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "labelId",
+              "description": "Global ID of an existing label.",
+              "type": {
+                "kind": "SCALAR",
+                "name": "LabelID",
+                "ofType": null
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "boardId",
+              "description": "Global ID of the issue board to mutate.",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "BoardsEpicBoardID",
+                  "ofType": null
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "defaultValue": null
+            }
+          ],
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "EpicBoardListCreatePayload",
+          "description": "Autogenerated return type of EpicBoardListCreate",
+          "fields": [
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "errors",
+              "description": "Errors encountered during execution of the mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "LIST",
+                  "name": null,
+                  "ofType": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "SCALAR",
+                      "name": "String",
+                      "ofType": null
+                    }
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "list",
+              "description": "Epic list in the epic board.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "EpicList",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "EpicConnection",
@@ -46081,6 +46203,33 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "epicBoardListCreate",
+              "description": null,
+              "args": [
+                {
+                  "name": "input",
+                  "description": null,
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "INPUT_OBJECT",
+                      "name": "EpicBoardListCreateInput",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "EpicBoardListCreatePayload",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "epicSetSubscription",
               "description": null,

doc/api/graphql/reference/index.md

@@ -357,7 +357,7 @@ Autogenerated return type of BoardListCreate.
 | ----- | ---- | ----------- |
 | `clientMutationId` | String | A unique identifier for the client performing the mutation. |
 | `errors` | String! => Array | Errors encountered during execution of the mutation. |
-| `list` | BoardList | List of the issue board. |
+| `list` | BoardList | Issue list in the issue board. |
 
 ### BoardListUpdateLimitMetricsPayload
 
@@ -1482,6 +1482,16 @@ Autogenerated return type of EpicBoardCreate.
 | `epicBoard` | EpicBoard | The created epic board. |
 | `errors` | String! => Array | Errors encountered during execution of the mutation. |
 
+### EpicBoardListCreatePayload
+
+Autogenerated return type of EpicBoardListCreate.
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Errors encountered during execution of the mutation. |
+| `list` | EpicList | Epic list in the epic board. |
+
 ### EpicDescendantCount
 
 Counts of descendent epics.

ee/app/graphql/ee/types/mutation_type.rb

@@ -37,6 +37,7 @@ module EE
         mount_mutation ::Mutations::Boards::Update
         mount_mutation ::Mutations::Boards::UpdateEpicUserPreferences
         mount_mutation ::Mutations::Boards::EpicBoards::Create
+        mount_mutation ::Mutations::Boards::EpicLists::Create
         mount_mutation ::Mutations::Boards::Lists::UpdateLimitMetrics
         mount_mutation ::Mutations::InstanceSecurityDashboard::AddProject
         mount_mutation ::Mutations::InstanceSecurityDashboard::RemoveProject

app/graphql/mutations/boards/lists/base.rb → ee/app/graphql/mutations/boards/epic_lists/create.rb

@@ -2,25 +2,32 @@
 
 module Mutations
   module Boards
-    module Lists
-      class Base < BaseMutation
-        include Mutations::ResolvesIssuable
+    module EpicLists
+      class Create < ::Mutations::Boards::Lists::BaseCreate
+        graphql_name 'EpicBoardListCreate'
 
-        argument :board_id, ::Types::GlobalIDType[::Board],
+        argument :board_id, ::Types::GlobalIDType[::Boards::EpicBoard],
                  required: true,
                  description: 'Global ID of the issue board to mutate.'
 
         field :list,
-              Types::BoardListType,
+              Types::Boards::EpicListType,
               null: true,
-              description: 'List of the issue board.'
+              description: 'Epic list in the epic board.'
 
-        authorize :admin_list
+        authorize :admin_epic_list
 
         private
 
         def find_object(id:)
-          GitlabSchema.object_from_id(id, expected_type: ::Board)
+          GitlabSchema.object_from_id(id, expected_type: ::Boards::EpicBoard)
+        end
+
+        def create_list(board, params)
+          create_list_service =
+            ::Boards::EpicLists::CreateService.new(board.group, current_user, params)
+
+          create_list_service.execute(board)
         end
       end
     end

ee/app/policies/ee/group_policy.rb

@@ -198,6 +198,7 @@ module EE
         enable :read_confidential_epic
         enable :destroy_epic_link
         enable :admin_epic_board
+        enable :admin_epic_list
       end
 
       rule { reporter & subepics_available }.policy do
@@ -214,6 +215,7 @@ module EE
         prevent :admin_epic
         prevent :update_epic
         prevent :destroy_epic
+        prevent :admin_epic_list
       end
 
       rule { auditor }.policy do

ee/app/services/boards/epic_lists/create_service.rb

+# frozen_string_literal: true
+
+module Boards
+  module EpicLists
+    class CreateService < ::Boards::Lists::BaseCreateService
+      extend ::Gitlab::Utils::Override
+
+      override :execute
+      def execute(board)
+        unless Feature.enabled?(:epic_boards, board.group)
+          return ServiceResponse.error(message: 'Epic boards feature is not enabled.')
+        end
+
+        super
+      end
+    end
+  end
+end

ee/spec/graphql/mutations/boards/epic_lists/create_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Mutations::Boards::EpicLists::Create do
+  let_it_be(:group) { create(:group, :private) }
+  let_it_be(:board) { create(:epic_board, group: group) }
+
+  before do
+    stub_licensed_features(epics: true)
+  end
+
+  it_behaves_like 'board lists create mutation'
+end

ee/spec/policies/group_policy_spec.rb

@@ -7,7 +7,8 @@ RSpec.describe GroupPolicy do
 
   let(:epic_rules) do
     %i(read_epic create_epic admin_epic destroy_epic read_confidential_epic
-       destroy_epic_link read_epic_board read_epic_list admin_epic_board)
+       destroy_epic_link read_epic_board read_epic_list admin_epic_board
+       admin_epic_list)
   end
 
   context 'when epics feature is disabled' do

ee/spec/requests/api/graphql/mutations/boards/epic_lists/create_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Create a label or backlog board list' do
+  let_it_be(:group) { create(:group, :private) }
+  let_it_be(:board) { create(:epic_board, group: group) }
+
+  before do
+    stub_licensed_features(epics: true)
+  end
+
+  it_behaves_like 'board lists create request' do
+    let(:mutation_name) { :epic_board_list_create }
+  end
+end

ee/spec/services/boards/epic_lists/create_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Boards::EpicLists::CreateService do
+  let_it_be(:parent) { create(:group) }
+  let_it_be(:board) { create(:epic_board, group: parent) }
+  let_it_be(:label) { create(:group_label, group: parent, name: 'in-progress') }
+
+  it_behaves_like 'board lists create service' do
+    def create_list(params)
+      create(:epic_list, params.merge(epic_board: board))
+    end
+  end
+
+  context 'when epic_boards feature flag is disabled' do
+    before do
+      stub_feature_flags(epic_boards: false)
+    end
+
+    it 'returns an error' do
+      response = described_class.new(parent, nil).execute(board)
+
+      expect(response.success?).to eq(false)
+      expect(response.errors).to include("Epic boards feature is not enabled.")
+    end
+  end
+end

spec/graphql/mutations/boards/lists/create_spec.rb

@@ -3,84 +3,8 @@
 require 'spec_helper'
 
 RSpec.describe Mutations::Boards::Lists::Create do
-  include GraphqlHelpers
-
   let_it_be(:group) { create(:group, :private) }
   let_it_be(:board) { create(:board, group: group) }
-  let_it_be(:user)  { create(:user) }
-  let_it_be(:guest) { create(:user) }
-
-  let(:current_user) { user }
-  let(:mutation) { described_class.new(object: nil, context: { current_user: current_user }, field: nil) }
-  let(:list_create_params) { {} }
-
-  before_all do
-    group.add_reporter(user)
-    group.add_guest(guest)
-  end
-
-  subject { mutation.resolve(board_id: board.to_global_id.to_s, **list_create_params) }
-
-  describe '#ready?' do
-    it 'raises an error if required arguments are missing' do
-      expect { mutation.ready?(board_id: 'some id') }
-        .to raise_error(Gitlab::Graphql::Errors::ArgumentError, /one and only one of/)
-    end
-
-    it 'raises an error if too many required arguments are specified' do
-      expect { mutation.ready?(board_id: 'some id', backlog: true, label_id: 'some label') }
-        .to raise_error(Gitlab::Graphql::Errors::ArgumentError, /one and only one of/)
-    end
-  end
-
-  describe '#resolve' do
-    context 'with proper permissions' do
-      describe 'backlog list' do
-        let(:list_create_params) { { backlog: true } }
-
-        it 'creates one and only one backlog' do
-          expect { subject }.to change { board.lists.backlog.count }.from(0).to(1)
-          expect(board.lists.backlog.first.list_type).to eq 'backlog'
-
-          backlog_id = board.lists.backlog.first.id
-
-          expect { subject }.not_to change { board.lists.backlog.count }
-          expect(board.lists.backlog.last.id).to eq backlog_id
-        end
-      end
-
-      describe 'label list' do
-        let_it_be(:dev_label) do
-          create(:group_label, title: 'Development', color: '#FFAABB', group: group)
-        end
-
-        let(:list_create_params) { { label_id: dev_label.to_global_id.to_s } }
-
-        it 'creates a new issue board list for labels' do
-          expect { subject }.to change { board.lists.count }.from(1).to(2)
-
-          new_list = subject[:list]
-
-          expect(new_list.title).to eq dev_label.title
-          expect(new_list.position).to eq 0
-        end
-
-        context 'when label not found' do
-          let(:list_create_params) { { label_id: "gid://gitlab/Label/#{non_existing_record_id}" } }
-
-          it 'returns an error' do
-            expect(subject[:errors]).to include 'Label not found'
-          end
-        end
-      end
-    end
-
-    context 'without proper permissions' do
-      let(:current_user) { guest }
 
-      it 'raises an error' do
-        expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
-      end
-    end
-  end
+  it_behaves_like 'board lists create mutation'
 end

spec/requests/api/graphql/mutations/boards/lists/create_spec.rb

@@ -3,52 +3,10 @@
 require 'spec_helper'
 
 RSpec.describe 'Create a label or backlog board list' do
-  include GraphqlHelpers
-
   let_it_be(:group) { create(:group, :private) }
   let_it_be(:board) { create(:board, group: group) }
-  let_it_be(:user)  { create(:user) }
-  let_it_be(:dev_label) do
-    create(:group_label, title: 'Development', color: '#FFAABB', group: group)
-  end
-
-  let(:current_user) { user }
-  let(:mutation) { graphql_mutation(:board_list_create, input) }
-  let(:mutation_response) { graphql_mutation_response(:board_list_create) }
-
-  context 'the user is not allowed to read board lists' do
-    let(:input) { { board_id: board.to_global_id.to_s, backlog: true } }
-
-    it_behaves_like 'a mutation that returns a top-level access error'
-  end
-
-  context 'when user has permissions to admin board lists' do
-    before do
-      group.add_reporter(current_user)
-    end
-
-    describe 'backlog list' do
-      let(:input) { { board_id: board.to_global_id.to_s, backlog: true } }
 
-      it 'creates the list' do
-        post_graphql_mutation(mutation, current_user: current_user)
-
-        expect(response).to have_gitlab_http_status(:success)
-        expect(mutation_response['list'])
-          .to include('position' => nil, 'listType' => 'backlog')
-      end
-    end
-
-    describe 'label list' do
-      let(:input) { { board_id: board.to_global_id.to_s, label_id: dev_label.to_global_id.to_s } }
-
-      it 'creates the list' do
-        post_graphql_mutation(mutation, current_user: current_user)
-
-        expect(response).to have_gitlab_http_status(:success)
-        expect(mutation_response['list'])
-          .to include('position' => 0, 'listType' => 'label', 'label' => include('title' => 'Development'))
-      end
-    end
+  it_behaves_like 'board lists create request' do
+    let(:mutation_name) { :board_list_create }
   end
 end

spec/services/boards/lists/create_service_spec.rb

@@ -3,91 +3,12 @@
 require 'spec_helper'
 
 RSpec.describe Boards::Lists::CreateService do
-  describe '#execute' do
-    shared_examples 'creating board lists' do
-      let_it_be(:user) { create(:user) }
-
-      before_all do
-        parent.add_developer(user)
-      end
-
-      subject(:service) { described_class.new(parent, user, label_id: label.id) }
-
-      context 'when board lists is empty' do
-        it 'creates a new list at beginning of the list' do
-          response = service.execute(board)
-
-          expect(response.success?).to eq(true)
-          expect(response.payload[:list].position).to eq 0
-        end
-      end
-
-      context 'when board lists has the done list' do
-        it 'creates a new list at beginning of the list' do
-          response = service.execute(board)
-
-          expect(response.success?).to eq(true)
-          expect(response.payload[:list].position).to eq 0
-        end
-      end
-
-      context 'when board lists has labels lists' do
-        it 'creates a new list at end of the lists' do
-          create(:list, board: board, position: 0)
-          create(:list, board: board, position: 1)
-
-          response = service.execute(board)
-
-          expect(response.success?).to eq(true)
-          expect(response.payload[:list].position).to eq 2
-        end
-      end
-
-      context 'when board lists has label and done lists' do
-        it 'creates a new list at end of the label lists' do
-          list1 = create(:list, board: board, position: 0)
-
-          list2 = service.execute(board).payload[:list]
-
-          expect(list1.reload.position).to eq 0
-          expect(list2.reload.position).to eq 1
-        end
-      end
-
-      context 'when provided label does not belong to the parent' do
-        it 'returns an error' do
-          label = create(:label, name: 'in-development')
-          service = described_class.new(parent, user, label_id: label.id)
-
-          response = service.execute(board)
-
-          expect(response.success?).to eq(false)
-          expect(response.errors).to include('Label not found')
-        end
-      end
-
-      context 'when backlog param is sent' do
-        it 'creates one and only one backlog list' do
-          service = described_class.new(parent, user, 'backlog' => true)
-          list = service.execute(board).payload[:list]
-
-          expect(list.list_type).to eq('backlog')
-          expect(list.position).to be_nil
-          expect(list).to be_valid
-
-          another_backlog = service.execute(board).payload[:list]
-
-          expect(another_backlog).to eq list
-        end
-      end
-    end
-
   context 'when board parent is a project' do
     let_it_be(:parent) { create(:project) }
     let_it_be(:board) { create(:board, project: parent) }
     let_it_be(:label) { create(:label, project: parent, name: 'in-progress') }
 
-      it_behaves_like 'creating board lists'
+    it_behaves_like 'board lists create service'
   end
 
   context 'when board parent is a group' do
@@ -95,7 +16,10 @@ RSpec.describe Boards::Lists::CreateService do
     let_it_be(:board) { create(:board, group: parent) }
     let_it_be(:label) { create(:group_label, group: parent, name: 'in-progress') }
 
-      it_behaves_like 'creating board lists'
+    it_behaves_like 'board lists create service'
   end
+
+  def create_list(params)
+    create(:list, params.merge(board: board))
   end
 end

spec/support/shared_examples/graphql/mutations/boards_list_create_shared_examples.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.shared_examples 'board lists create mutation' do
+  include GraphqlHelpers
+
+  let_it_be(:user) { create(:user) }
+
+  let(:mutation) { described_class.new(object: nil, context: { current_user: user }, field: nil) }
+  let(:list_create_params) { {} }
+
+  subject { mutation.resolve(board_id: board.to_global_id.to_s, **list_create_params) }
+
+  describe '#ready?' do
+    it 'raises an error if required arguments are missing' do
+      expect { mutation.ready?(board_id: 'some id') }
+        .to raise_error(Gitlab::Graphql::Errors::ArgumentError, /one and only one of/)
+    end
+
+    it 'raises an error if too many required arguments are specified' do
+      expect { mutation.ready?(board_id: 'some id', backlog: true, label_id: 'some label') }
+        .to raise_error(Gitlab::Graphql::Errors::ArgumentError, /one and only one of/)
+    end
+  end
+
+  describe '#resolve' do
+    context 'with proper permissions' do
+      before_all do
+        group.add_reporter(user)
+      end
+
+      describe 'backlog list' do
+        let(:list_create_params) { { backlog: true } }
+
+        it 'creates one and only one backlog' do
+          expect { subject }.to change { board.lists.backlog.count }.by(1)
+          expect(board.lists.backlog.first.list_type).to eq 'backlog'
+
+          backlog_id = board.lists.backlog.first.id
+
+          expect { subject }.not_to change { board.lists.backlog.count }
+          expect(board.lists.backlog.last.id).to eq backlog_id
+        end
+      end
+
+      describe 'label list' do
+        let_it_be(:dev_label) do
+          create(:group_label, title: 'Development', color: '#FFAABB', group: group)
+        end
+
+        let(:list_create_params) { { label_id: dev_label.to_global_id.to_s } }
+
+        it 'creates a new label board list' do
+          expect { subject }.to change { board.lists.count }.by(1)
+
+          new_list = subject[:list]
+
+          expect(new_list.title).to eq dev_label.title
+          expect(new_list.position).to eq 0
+        end
+
+        context 'when label not found' do
+          let(:list_create_params) { { label_id: "gid://gitlab/Label/#{non_existing_record_id}" } }
+
+          it 'returns an error' do
+            expect(subject[:errors]).to include 'Label not found'
+          end
+        end
+      end
+    end
+
+    context 'without proper permissions' do
+      before_all do
+        group.add_guest(user)
+      end
+
+      it 'raises an error' do
+        expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+      end
+    end
+  end
+end

spec/support/shared_examples/requests/api/graphql/mutations/create_list_shared_examples.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.shared_examples 'board lists create request' do
+  include GraphqlHelpers
+
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:dev_label) do
+    create(:group_label, title: 'Development', color: '#FFAABB', group: group)
+  end
+
+  let(:mutation) { graphql_mutation(mutation_name, input) }
+  let(:mutation_response) { graphql_mutation_response(mutation_name) }
+
+  context 'the user is not allowed to read board lists' do
+    let(:input) { { board_id: board.to_global_id.to_s, backlog: true } }
+
+    it_behaves_like 'a mutation that returns a top-level access error'
+  end
+
+  context 'when user has permissions to admin board lists' do
+    before do
+      group.add_reporter(current_user)
+    end
+
+    describe 'backlog list' do
+      let(:input) { { board_id: board.to_global_id.to_s, backlog: true } }
+
+      it 'creates the list' do
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(response).to have_gitlab_http_status(:success)
+        expect(mutation_response['list'])
+          .to include('position' => nil, 'listType' => 'backlog')
+      end
+    end
+
+    describe 'label list' do
+      let(:input) { { board_id: board.to_global_id.to_s, label_id: dev_label.to_global_id.to_s } }
+
+      it 'creates the list' do
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(response).to have_gitlab_http_status(:success)
+        expect(mutation_response['list'])
+          .to include('position' => 0, 'listType' => 'label', 'label' => include('title' => 'Development'))
+      end
+    end
+  end
+end

spec/support/shared_examples/services/boards/lists_create_service_shared_examples.rb

+# frozen_string_literal: true
+
+RSpec.shared_examples 'board lists create service' do
+  describe '#execute' do
+    let_it_be(:user) { create(:user) }
+
+    before_all do
+      parent.add_developer(user)
+    end
+
+    subject(:service) { described_class.new(parent, user, label_id: label.id) }
+
+    context 'when board lists is empty' do
+      it 'creates a new list at beginning of the list' do
+        response = service.execute(board)
+
+        expect(response.success?).to eq(true)
+        expect(response.payload[:list].position).to eq 0
+      end
+    end
+
+    context 'when board lists has the done list' do
+      it 'creates a new list at beginning of the list' do
+        response = service.execute(board)
+
+        expect(response.success?).to eq(true)
+        expect(response.payload[:list].position).to eq 0
+      end
+    end
+
+    context 'when board lists has labels lists' do
+      it 'creates a new list at end of the lists' do
+        create_list(position: 0)
+        create_list(position: 1)
+
+        response = service.execute(board)
+
+        expect(response.success?).to eq(true)
+        expect(response.payload[:list].position).to eq 2
+      end
+    end
+
+    context 'when board lists has label and done lists' do
+      it 'creates a new list at end of the label lists' do
+        list1 = create_list(position: 0)
+
+        list2 = service.execute(board).payload[:list]
+
+        expect(list1.reload.position).to eq 0
+        expect(list2.reload.position).to eq 1
+      end
+    end
+
+    context 'when provided label does not belong to the parent' do
+      it 'returns an error' do
+        label = create(:label, name: 'in-development')
+        service = described_class.new(parent, user, label_id: label.id)
+
+        response = service.execute(board)
+
+        expect(response.success?).to eq(false)
+        expect(response.errors).to include('Label not found')
+      end
+    end
+
+    context 'when backlog param is sent' do
+      it 'creates one and only one backlog list' do
+        service = described_class.new(parent, user, 'backlog' => true)
+        list = service.execute(board).payload[:list]
+
+        expect(list.list_type).to eq('backlog')
+        expect(list.position).to be_nil
+        expect(list).to be_valid
+
+        another_backlog = service.execute(board).payload[:list]
+
+        expect(another_backlog).to eq list
+      end
+    end
+  end
+end