Add graphQL mutation for destroying board lists

- add mutation and specs
- update the graphql documentation
- update Boards::Lists::DestroyService to use ServiceResponse

app/controllers/boards/lists_controller.rb

@@ -42,7 +42,7 @@ module Boards
       list = board.lists.destroyable.find(params[:id])
       service = Boards::Lists::DestroyService.new(board_parent, current_user)
 
-      if service.execute(list)
+      if service.execute(list).success?
         head :ok
       else
         head :unprocessable_entity

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

+# frozen_string_literal: true
+
+module Mutations
+  module Boards
+    module Lists
+      class Destroy < ::Mutations::BaseMutation
+        graphql_name 'DestroyBoardList'
+
+        field :list,
+            Types::BoardListType,
+            null: true,
+            description: 'The list after mutation.'
+
+        argument :list_id, ::Types::GlobalIDType[::List],
+                  required: true,
+                  loads: Types::BoardListType,
+                  description: 'Global ID of the list to destroy. Only label lists are accepted.'
+
+        def resolve(list:)
+          raise_resource_not_available_error! unless can_admin_list?(list)
+
+          response = ::Boards::Lists::DestroyService.new(list.board.resource_parent, current_user)
+            .execute(list)
+
+          {
+            list: response.success? ? nil : list,
+            errors: response.errors
+          }
+        end
+
+        private
+
+        def can_admin_list?(list)
+          return false unless list.present?
+
+          Ability.allowed?(current_user, :admin_list, list.board)
+        end
+      end
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -18,6 +18,7 @@ module Types
     mount_mutation Mutations::Boards::Issues::IssueMoveList
     mount_mutation Mutations::Boards::Lists::Create
     mount_mutation Mutations::Boards::Lists::Update
+    mount_mutation Mutations::Boards::Lists::Destroy
     mount_mutation Mutations::Branches::Create, calls_gitaly: true
     mount_mutation Mutations::Commits::Create, calls_gitaly: true
     mount_mutation Mutations::Discussions::ToggleResolve

app/services/boards/lists/destroy_service.rb

@@ -4,7 +4,9 @@ module Boards
   module Lists
     class DestroyService < Boards::BaseService
       def execute(list)
-        return false unless list.destroyable?
+        unless list.destroyable?
+          return ServiceResponse.error(message: "The list cannot be destroyed. Only label lists can be destroyed.")
+        end
 
         @board = list.board
 
@@ -12,6 +14,8 @@ module Boards
           decrement_higher_lists(list)
           remove_list(list)
         end
+
+        ServiceResponse.success
       end
 
       private
@@ -26,7 +30,7 @@ module Boards
       # rubocop: enable CodeReuse/ActiveRecord
 
       def remove_list(list)
-        list.destroy
+        list.destroy!
       end
     end
   end

changelogs/unreleased/229834-destroy-board-list-graphql.yml

+---
+title: Destroy issue board list via GraphQL
+merge_request: 43081
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -4495,6 +4495,41 @@ input DestroyBoardInput {
   id: BoardID!
 }
 
+"""
+Autogenerated input type of DestroyBoardList
+"""
+input DestroyBoardListInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Global ID of the list to destroy. Only label lists are accepted.
+  """
+  listId: ListID!
+}
+
+"""
+Autogenerated return type of DestroyBoardList
+"""
+type DestroyBoardListPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Errors encountered during execution of the mutation.
+  """
+  errors: [String!]!
+
+  """
+  The list after mutation.
+  """
+  list: BoardList
+}
+
 """
 Autogenerated return type of DestroyBoard
 """
@@ -9280,6 +9315,11 @@ Identifier of Label
 """
 scalar LabelID
 
+"""
+Identifier of List
+"""
+scalar ListID
+
 """
 List limit metric setting
 """
@@ -10835,6 +10875,7 @@ type Mutation {
   designManagementMove(input: DesignManagementMoveInput!): DesignManagementMovePayload
   designManagementUpload(input: DesignManagementUploadInput!): DesignManagementUploadPayload
   destroyBoard(input: DestroyBoardInput!): DestroyBoardPayload
+  destroyBoardList(input: DestroyBoardListInput!): DestroyBoardListPayload
   destroyNote(input: DestroyNoteInput!): DestroyNotePayload
   destroySnippet(input: DestroySnippetInput!): DestroySnippetPayload
 

doc/api/graphql/reference/gitlab_schema.json

@@ -12400,6 +12400,108 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "INPUT_OBJECT",
+          "name": "DestroyBoardListInput",
+          "description": "Autogenerated input type of DestroyBoardList",
+          "fields": null,
+          "inputFields": [
+            {
+              "name": "listId",
+              "description": "Global ID of the list to destroy. Only label lists are accepted.",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "ListID",
+                  "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": "DestroyBoardListPayload",
+          "description": "Autogenerated return type of DestroyBoardList",
+          "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": "The list after mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "BoardList",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "DestroyBoardPayload",
@@ -25732,6 +25834,16 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "SCALAR",
+          "name": "ListID",
+          "description": "Identifier of List",
+          "fields": null,
+          "inputFields": null,
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "ENUM",
           "name": "ListLimitMetric",
@@ -31091,6 +31203,33 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "destroyBoardList",
+              "description": null,
+              "args": [
+                {
+                  "name": "input",
+                  "description": null,
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "INPUT_OBJECT",
+                      "name": "DestroyBoardListInput",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "DestroyBoardListPayload",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "destroyNote",
               "description": null,

doc/api/graphql/reference/index.md

@@ -740,6 +740,16 @@ A specific version in which designs were added, modified or deleted.
 | `id` | ID! | ID of the design version |
 | `sha` | ID! | SHA of the design version |
 
+### DestroyBoardListPayload
+
+Autogenerated return type of DestroyBoardList.
+
+| 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` | BoardList | The list after mutation. |
+
 ### DestroyBoardPayload
 
 Autogenerated return type of DestroyBoard.

lib/api/boards_responses.rb

@@ -45,7 +45,7 @@ module API
         def destroy_list(list)
           destroy_conditionally!(list) do |list|
             service = ::Boards::Lists::DestroyService.new(board_parent, current_user)
-            unless service.execute(list)
+            if service.execute(list).error?
               render_api_error!({ error: 'List could not be deleted!' }, 400)
             end
           end

spec/controllers/boards/lists_controller_spec.rb

@@ -260,6 +260,17 @@ RSpec.describe Boards::ListsController do
       end
     end
 
+    context 'with an error service response' do
+      it 'returns an unprocessable entity response' do
+        allow(Boards::Lists::DestroyService).to receive(:new)
+          .and_return(double(execute: ServiceResponse.error(message: 'error')))
+
+        remove_board_list user: user, board: board, list: planning
+
+        expect(response).to have_gitlab_http_status(:unprocessable_entity)
+      end
+    end
+
     def remove_board_list(user:, board:, list:)
       sign_in(user)
 

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

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Mutations::Boards::Lists::Destroy do
+  include GraphqlHelpers
+
+  let_it_be(:current_user, reload: true) { create(:user) }
+  let_it_be(:project, reload: true) { create(:project) }
+  let_it_be(:board) { create(:board, project: project) }
+  let_it_be(:list) { create(:list, board: board) }
+  let(:mutation) do
+    variables = {
+      list_id: GitlabSchema.id_from_object(list).to_s
+    }
+
+    graphql_mutation(:destroy_board_list, variables)
+  end
+
+  subject { post_graphql_mutation(mutation, current_user: current_user) }
+
+  def mutation_response
+    graphql_mutation_response(:destroy_board_list)
+  end
+
+  context 'when the user does not have permission' do
+    it_behaves_like 'a mutation that returns a top-level access error'
+
+    it 'does not destroy the list' do
+      expect { subject }.not_to change { List.count }
+    end
+  end
+
+  context 'when the user has permission' do
+    before do
+      project.add_maintainer(current_user)
+    end
+
+    context 'when given id is not for a list' do
+      let_it_be(:list) { build_stubbed(:issue, project: project) }
+
+      it 'returns an error' do
+        subject
+
+        expect(graphql_errors.first['message']).to include('does not represent an instance of List')
+      end
+    end
+
+    context 'when everything is ok' do
+      it 'destroys the list' do
+        expect { subject }.to change { List.count }.from(2).to(1)
+      end
+
+      it 'returns an empty list' do
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(mutation_response).to have_key('list')
+        expect(mutation_response['list']).to be_nil
+      end
+    end
+
+    context 'when the list is not destroyable' do
+      let_it_be(:list) { create(:list, board: board, list_type: :backlog) }
+
+      it 'does not destroy the list' do
+        expect { subject }.not_to change { List.count }.from(3)
+      end
+
+      it 'returns an error and not nil list' do
+        subject
+
+        expect(mutation_response['errors']).not_to be_empty
+        expect(mutation_response['list']).not_to be_nil
+      end
+    end
+  end
+end