Mutation for creaing a board list

either a backlog and label list

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

+# frozen_string_literal: true
+
+module Mutations
+  module Boards
+    module Lists
+      class Base < BaseMutation
+        include Mutations::ResolvesIssuable
+
+        argument :board_id, ::Types::GlobalIDType[::Board],
+                 required: true,
+                 description: 'The Global ID of the issue board to mutate'
+
+        field :list,
+              Types::BoardListType,
+              null: true,
+              description: 'List of the issue board'
+
+        authorize :admin_list
+
+        private
+
+        def find_object(id:)
+          GitlabSchema.object_from_id(id, expected_type: ::Board)
+        end
+      end
+    end
+  end
+end

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

+# frozen_string_literal: true
+
+module Mutations
+  module Boards
+    module Lists
+      class Create < Base
+        graphql_name 'BoardListCreate'
+
+        argument :backlog, GraphQL::BOOLEAN_TYPE,
+                 required: false,
+                 description: 'Create the backlog list'
+
+        argument :label_id, ::Types::GlobalIDType[::Label],
+                 required: false,
+                 description: '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)
+
+          authorize_list_type_resource!(board, params)
+
+          list = create_list(board, params)
+
+          {
+            list: list.valid? ? list : nil,
+            errors: errors_on_object(list)
+          }
+        end
+
+        private
+
+        def authorize_list_type_resource!(board, params)
+          return unless params[:label_id]
+
+          labels = ::Labels::AvailableLabelsService.new(current_user, board.resource_parent, params)
+            .filter_labels_ids_in_param(:label_id)
+
+          unless labels.present?
+            raise Gitlab::Graphql::Errors::ArgumentError, 'Label not found!'
+          end
+        end
+
+        def create_list(board, params)
+          create_list_service =
+            ::Boards::Lists::CreateService.new(board.resource_parent, current_user, params)
+
+          create_list_service.execute(board)
+        end
+
+        def create_list_params(args)
+          params = args.slice(*mutually_exclusive_args).with_indifferent_access
+          params[:label_id] = GitlabSchema.parse_gid(params[:label_id]).model_id if params[:label_id]
+
+          params
+        end
+
+        def mutually_exclusive_args
+          [:backlog, :label_id]
+        end
+      end
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -15,6 +15,7 @@ module Types
     mount_mutation Mutations::AwardEmojis::Remove
     mount_mutation Mutations::AwardEmojis::Toggle
     mount_mutation Mutations::Boards::Issues::IssueMoveList
+    mount_mutation Mutations::Boards::Lists::Create
     mount_mutation Mutations::Branches::Create, calls_gitaly: true
     mount_mutation Mutations::Commits::Create, calls_gitaly: true
     mount_mutation Mutations::Discussions::ToggleResolve

app/services/labels/available_labels_service.rb

@@ -30,7 +30,7 @@ module Labels
     end
 
     def filter_labels_ids_in_param(key)
-      ids = params[key].to_a
+      ids = Array.wrap(params[key])
       return [] if ids.empty?
 
       # rubocop:disable CodeReuse/ActiveRecord

changelogs/unreleased/215533-graphql-add-mutation-to-create-the-default-backlog-list-for-a-boar.yml

+---
+title: 'Add mutation to create a label or default backlog list for an issue board'
+merge_request: 31233
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -1165,6 +1165,11 @@ input BoardEpicIssueInput {
   weight: String
 }
 
+"""
+Identifier of Board
+"""
+scalar BoardID
+
 """
 Represents a list for an issue board
 """
@@ -1270,6 +1275,51 @@ type BoardListConnection {
   pageInfo: PageInfo!
 }
 
+"""
+Autogenerated input type of BoardListCreate
+"""
+input BoardListCreateInput {
+  """
+  Create the backlog list
+  """
+  backlog: Boolean
+
+  """
+  The Global ID of the issue board to mutate
+  """
+  boardId: BoardID!
+
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  ID of an existing label
+  """
+  labelId: LabelID
+}
+
+"""
+Autogenerated return type of BoardListCreate
+"""
+type BoardListCreatePayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Errors encountered during execution of the mutation.
+  """
+  errors: [String!]!
+
+  """
+  List of the issue board
+  """
+  list: BoardList
+}
+
 """
 An edge in a connection.
 """
@@ -8103,6 +8153,11 @@ type LabelEdge {
   node: Label
 }
 
+"""
+Identifier of Label
+"""
+scalar LabelID
+
 """
 List limit metric setting
 """
@@ -9387,6 +9442,7 @@ type Mutation {
   awardEmojiAdd(input: AwardEmojiAddInput!): AwardEmojiAddPayload
   awardEmojiRemove(input: AwardEmojiRemoveInput!): AwardEmojiRemovePayload
   awardEmojiToggle(input: AwardEmojiToggleInput!): AwardEmojiTogglePayload
+  boardListCreate(input: BoardListCreateInput!): BoardListCreatePayload
   boardListUpdateLimitMetrics(input: BoardListUpdateLimitMetricsInput!): BoardListUpdateLimitMetricsPayload
   commitCreate(input: CommitCreateInput!): CommitCreatePayload
   configureSast(input: ConfigureSastInput!): ConfigureSastPayload

doc/api/graphql/reference/gitlab_schema.json

@@ -3108,6 +3108,16 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "SCALAR",
+          "name": "BoardID",
+          "description": "Identifier of Board",
+          "fields": null,
+          "inputFields": null,
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "BoardList",
@@ -3407,6 +3417,128 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "INPUT_OBJECT",
+          "name": "BoardListCreateInput",
+          "description": "Autogenerated input type of BoardListCreate",
+          "fields": null,
+          "inputFields": [
+            {
+              "name": "boardId",
+              "description": "The Global ID of the issue board to mutate",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "BoardID",
+                  "ofType": null
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "backlog",
+              "description": "Create the backlog list",
+              "type": {
+                "kind": "SCALAR",
+                "name": "Boolean",
+                "ofType": null
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "labelId",
+              "description": "ID of an existing label",
+              "type": {
+                "kind": "SCALAR",
+                "name": "LabelID",
+                "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": "BoardListCreatePayload",
+          "description": "Autogenerated return type of BoardListCreate",
+          "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": "List of the issue board",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "BoardList",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "BoardListEdge",
@@ -22508,6 +22640,16 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "SCALAR",
+          "name": "LabelID",
+          "description": "Identifier of Label",
+          "fields": null,
+          "inputFields": null,
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "ENUM",
           "name": "ListLimitMetric",
@@ -26491,6 +26633,33 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "boardListCreate",
+              "description": null,
+              "args": [
+                {
+                  "name": "input",
+                  "description": null,
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "INPUT_OBJECT",
+                      "name": "BoardListCreateInput",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "BoardListCreatePayload",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "boardListUpdateLimitMetrics",
               "description": null,

doc/api/graphql/reference/index.md

@@ -214,6 +214,16 @@ Represents a list for an issue board
 | `position` | Int | Position of list within the board |
 | `title` | String! | Title of the list |
 
+## BoardListCreatePayload
+
+Autogenerated return type of BoardListCreate
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `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 |
+
 ## BoardListUpdateLimitMetricsPayload
 
 Autogenerated return type of BoardListUpdateLimitMetrics

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

+# frozen_string_literal: true
+
+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 backlog or labelId is required')
+    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 backlog or labelId is required')
+    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
+      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
+end

spec/services/labels/available_labels_service_spec.rb

@@ -88,6 +88,12 @@ RSpec.describe Labels::AvailableLabelsService do
         expect(result).to match_array([group_label.id])
       end
     end
+
+    it 'accepts a single id parameter' do
+      result = described_class.new(user, project, label_id: project_label.id).filter_labels_ids_in_param(:label_id)
+
+      expect(result).to match_array([project_label.id])
+    end
   end
 
   describe '#available_labels' do