Allow to create epics with GraphQL

Add mutation to create epics on GraphQL

doc/api/graphql/reference/index.md

@@ -66,6 +66,14 @@ The API can be explored interactively using the [GraphiQL IDE](../index.md#graph
 | `errors` | String! => Array | Reasons why the mutation failed. |
 | `note` | Note | The note after mutation |
 
+### CreateEpicPayload
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Reasons why the mutation failed. |
+| `epic` | Epic | The created epic |
+
 ### CreateImageDiffNotePayload
 
 | Name  | Type  | Description |

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

@@ -10,6 +10,7 @@ module EE
         mount_mutation ::Mutations::DesignManagement::Delete, calls_gitaly: true
         mount_mutation ::Mutations::EpicTree::Reorder
         mount_mutation ::Mutations::Epics::Update
+        mount_mutation ::Mutations::Epics::Create
       end
     end
   end

ee/app/graphql/mutations/concerns/mutations/shared_epic_arguments.rb

+# frozen_string_literal: true
+
+module Mutations
+  module SharedEpicArguments
+    extend ActiveSupport::Concern
+
+    prepended do
+      argument :group_path, GraphQL::ID_TYPE,
+               required: true,
+               description: "The group the epic to mutate is in"
+
+      argument :title,
+                GraphQL::STRING_TYPE,
+                required: false,
+                description: 'The title of the epic'
+
+      argument :description,
+                GraphQL::STRING_TYPE,
+                required: false,
+                description: 'The description of the epic'
+
+      argument :start_date_fixed,
+                GraphQL::STRING_TYPE,
+                required: false,
+                description: 'The start date of the epic'
+
+      argument :due_date_fixed,
+                GraphQL::STRING_TYPE,
+                required: false,
+                description: 'The end date of the epic'
+
+      argument :start_date_is_fixed,
+                GraphQL::BOOLEAN_TYPE,
+                required: false,
+                description: 'Indicates start date should be sourced from start_date_fixed field not the issue milestones'
+
+      argument :due_date_is_fixed,
+                GraphQL::BOOLEAN_TYPE,
+                required: false,
+                description: 'Indicates end date should be sourced from due_date_fixed field not the issue milestones'
+    end
+
+    def validate_arguments!(args)
+      if args.empty?
+        raise Gitlab::Graphql::Errors::ArgumentError,
+          'The list of epic attributes is empty'
+      end
+    end
+  end
+end

ee/app/graphql/mutations/epics/create.rb

+# frozen_string_literal: true
+
+module Mutations
+  module Epics
+    class Create < BaseMutation
+      include Mutations::ResolvesGroup
+      prepend Mutations::SharedEpicArguments
+
+      graphql_name 'CreateEpic'
+
+      authorize :create_epic
+
+      field :epic,
+            Types::EpicType,
+            null: true,
+            description: 'The created epic'
+
+      def resolve(args)
+        group_path = args.delete(:group_path)
+
+        validate_arguments!(args)
+
+        group = authorized_find!(group_path: group_path)
+        epic = ::Epics::CreateService.new(group, current_user, args).execute
+
+        response_object = epic if epic.valid?
+
+        {
+          epic: response_object,
+          errors: errors_on_object(epic)
+        }
+      end
+
+      private
+
+      def find_object(group_path:)
+        resolve_group(full_path: group_path)
+      end
+    end
+  end
+end

ee/app/graphql/mutations/epics/update.rb

@@ -4,47 +4,14 @@ module Mutations
   module Epics
     class Update < BaseMutation
       include Mutations::ResolvesGroup
+      prepend Mutations::SharedEpicArguments
 
       graphql_name 'UpdateEpic'
 
-      argument :group_path, GraphQL::ID_TYPE,
-               required: true,
-               description: "The group the epic to mutate is in"
-
       argument :iid, GraphQL::STRING_TYPE,
                required: true,
                description: "The iid of the epic to mutate"
 
-      argument :title,
-                GraphQL::STRING_TYPE,
-                required: false,
-                description: 'The title of the epic'
-
-      argument :description,
-                GraphQL::STRING_TYPE,
-                required: false,
-                description: 'The description of the epic'
-
-      argument :start_date_fixed,
-                GraphQL::STRING_TYPE,
-                required: false,
-                description: 'The start date of the epic'
-
-      argument :due_date_fixed,
-                GraphQL::STRING_TYPE,
-                required: false,
-                description: 'The end date of the epic'
-
-      argument :start_date_is_fixed,
-                GraphQL::BOOLEAN_TYPE,
-                required: false,
-                description: 'Indicates start date should be sourced from start_date_fixed field not the issue milestones'
-
-      argument :due_date_is_fixed,
-                GraphQL::BOOLEAN_TYPE,
-                required: false,
-                description: 'Indicates end date should be sourced from due_date_fixed field not the issue milestones'
-
       argument :state_event,
                 Types::EpicStateEventEnum,
                 required: false,
@@ -61,10 +28,7 @@ module Mutations
         group_path = args.delete(:group_path)
         epic_iid = args.delete(:iid)
 
-        if args.empty?
-          raise Gitlab::Graphql::Errors::ArgumentError,
-            "The list of attributes to update is empty"
-        end
+        validate_arguments!(args)
 
         epic = authorized_find!(group_path: group_path, iid: epic_iid)
         epic = ::Epics::UpdateService.new(epic.group, current_user, args).execute(epic)

ee/changelogs/unreleased/issue_33778.yml

+---
+title: Allow to create epics with GraphQL
+merge_request: 19030
+author:
+type: added

ee/spec/requests/api/graphql/mutations/epics/create_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Creating an Epic' do
+  include GraphqlHelpers
+
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+
+  let(:attributes) do
+    {
+      title: 'title',
+      description: 'some description',
+      start_date_fixed: '2019-09-17',
+      due_date_fixed: '2019-09-18',
+      start_date_is_fixed: true,
+      due_date_is_fixed: true
+    }
+  end
+
+  let(:mutation) do
+    params = { group_path: group.full_path }.merge(attributes)
+
+    graphql_mutation(:create_epic, params)
+  end
+
+  def mutation_response
+    graphql_mutation_response(:create_epic)
+  end
+
+  context 'when the user does not have permission' do
+    before do
+      stub_licensed_features(epics: true)
+    end
+
+    it_behaves_like 'a mutation that returns top-level errors',
+      errors: ['The resource that you are attempting to access does not exist '\
+               'or you don\'t have permission to perform this action']
+
+    it 'does not create epic' do
+      expect { post_graphql_mutation(mutation, current_user: current_user) }.not_to change(Epic, :count)
+    end
+  end
+
+  context 'when the user has permission' do
+    before do
+      group.add_reporter(current_user)
+    end
+
+    context 'when epics are disabled' do
+      before do
+        stub_licensed_features(epics: false)
+      end
+
+      it_behaves_like 'a mutation that returns top-level errors',
+        errors: ['The resource that you are attempting to access does not '\
+                 'exist or you don\'t have permission to perform this action']
+    end
+
+    context 'when epics are enabled' do
+      before do
+        stub_licensed_features(epics: true)
+      end
+
+      it 'creates the epic' do
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        epic_hash = mutation_response['epic']
+        expect(epic_hash['title']).to eq('title')
+        expect(epic_hash['description']).to eq('some description')
+        expect(epic_hash['startDateFixed']).to eq('2019-09-17')
+        expect(epic_hash['startDateIsFixed']).to eq(true)
+        expect(epic_hash['dueDateFixed']).to eq('2019-09-18')
+        expect(epic_hash['dueDateIsFixed']).to eq(true)
+      end
+
+      context 'when there are ActiveRecord validation errors' do
+        let(:attributes) { { title: '' } }
+
+        it_behaves_like 'a mutation that returns errors in the response',
+          errors: ["Title can't be blank"]
+
+        it 'does not create the epic' do
+          expect { post_graphql_mutation(mutation, current_user: current_user) }.not_to change(Epic, :count)
+        end
+      end
+
+      context 'when the list of attributes is empty' do
+        let(:attributes) { {} }
+
+        it_behaves_like 'a mutation that returns top-level errors',
+          errors: ['The list of epic attributes is empty']
+
+        it 'does not create the epic' do
+          expect { post_graphql_mutation(mutation, current_user: current_user) }.not_to change(Epic, :count)
+        end
+      end
+    end
+  end
+end

ee/spec/requests/api/graphql/mutations/epics/update_spec.rb

@@ -117,7 +117,7 @@ describe 'Updating an Epic' do
         let(:attributes) { {} }
 
         it_behaves_like 'a mutation that returns top-level errors',
-          errors: ['The list of attributes to update is empty']
+          errors: ['The list of epic attributes is empty']
       end
     end
   end