GraphQL mutations for add, remove and toggle emoji

Adding new `AddAwardEmoji`, `RemoveAwardEmoji` and `ToggleAwardEmoji`
GraphQL mutations.

Adding new `#authorized_find_with_pre_checks!` and (unused, but for
completeness `#authorized_find_with_post_checks!`) authorization
methods. These allow us to perform an authorized find, and run our own
additional checks before or after the authorization runs.

https://gitlab.com/gitlab-org/gitlab-ce/issues/62826

app/graphql/mutations/award_emojis/add.rb

+# frozen_string_literal: true
+
+module Mutations
+  module AwardEmojis
+    class Add < Base
+      graphql_name 'AddAwardEmoji'
+
+      def resolve(args)
+        awardable = authorized_find!(id: args[:awardable_id])
+
+        check_object_is_awardable!(awardable)
+
+        # TODO this will be handled by AwardEmoji::AddService
+        # See https://gitlab.com/gitlab-org/gitlab-ce/issues/63372 and
+        # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29782
+        award = awardable.create_award_emoji(args[:name], current_user)
+
+        {
+          award_emoji: (award if award.persisted?),
+          errors: errors_on_object(award)
+        }
+      end
+    end
+  end
+end

app/graphql/mutations/award_emojis/base.rb

+# frozen_string_literal: true
+
+module Mutations
+  module AwardEmojis
+    class Base < BaseMutation
+      include Gitlab::Graphql::Authorize::AuthorizeResource
+
+      authorize :award_emoji
+
+      argument :awardable_id,
+               GraphQL::ID_TYPE,
+               required: true,
+               description: 'The global id of the awardable resource'
+
+      argument :name,
+               GraphQL::STRING_TYPE,
+               required: true,
+               description: copy_field_description(Types::AwardEmojis::AwardEmojiType, :name)
+
+      field :award_emoji,
+            Types::AwardEmojis::AwardEmojiType,
+            null: true,
+            description: 'The award emoji after mutation'
+
+      private
+
+      def find_object(id:)
+        GitlabSchema.object_from_id(id)
+      end
+
+      # Called by mutations methods after performing an authorization check
+      # of an awardable object.
+      def check_object_is_awardable!(object)
+        unless object.is_a?(Awardable) && object.emoji_awardable?
+          raise Gitlab::Graphql::Errors::ResourceNotAvailable,
+                'Cannot award emoji to this resource'
+        end
+      end
+    end
+  end
+end

app/graphql/mutations/award_emojis/remove.rb

+# frozen_string_literal: true
+
+module Mutations
+  module AwardEmojis
+    class Remove < Base
+      graphql_name 'RemoveAwardEmoji'
+
+      def resolve(args)
+        awardable = authorized_find!(id: args[:awardable_id])
+
+        check_object_is_awardable!(awardable)
+
+        # TODO this check can be removed once AwardEmoji services are available.
+        # See https://gitlab.com/gitlab-org/gitlab-ce/issues/63372 and
+        # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29782
+        unless awardable.awarded_emoji?(args[:name], current_user)
+          raise Gitlab::Graphql::Errors::ResourceNotAvailable,
+                'You have not awarded emoji of type name to the awardable'
+        end
+
+        # TODO this will be handled by AwardEmoji::DestroyService
+        # See https://gitlab.com/gitlab-org/gitlab-ce/issues/63372 and
+        # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29782
+        awardable.remove_award_emoji(args[:name], current_user)
+
+        {
+          # Mutation response is always a `nil` award_emoji
+          errors: []
+        }
+      end
+    end
+  end
+end

app/graphql/mutations/award_emojis/toggle.rb

+# frozen_string_literal: true
+
+module Mutations
+  module AwardEmojis
+    class Toggle < Base
+      graphql_name 'ToggleAwardEmoji'
+
+      field :toggledOn,
+            GraphQL::BOOLEAN_TYPE,
+            null: false,
+            description: 'True when the emoji was awarded, false when it was removed'
+
+      def resolve(args)
+        awardable = authorized_find!(id: args[:awardable_id])
+
+        check_object_is_awardable!(awardable)
+
+        # TODO this will be handled by AwardEmoji::ToggleService
+        # See https://gitlab.com/gitlab-org/gitlab-ce/issues/63372 and
+        # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29782
+        award = awardable.toggle_award_emoji(args[:name], current_user)
+
+        # Destroy returns a collection :(
+        award = award.first if award.is_a?(Array)
+
+        errors = errors_on_object(award)
+
+        toggled_on = awardable.awarded_emoji?(args[:name], current_user)
+
+        {
+          # For consistency with the AwardEmojis::Remove mutation, only return
+          # the AwardEmoji if it was created and not destroyed
+          award_emoji: (award if toggled_on),
+          errors: errors,
+          toggled_on: toggled_on
+        }
+      end
+    end
+  end
+end

app/graphql/mutations/base_mutation.rb

@@ -2,6 +2,8 @@
 module Mutations
   class BaseMutation < GraphQL::Schema::RelayClassicMutation
+    prepend Gitlab::Graphql::CopyFieldDescription
+
     field :errors, [GraphQL::STRING_TYPE],
           null: false,
           description: "Reasons why the mutation failed."
@@ -9,5 +11,10 @@ module Mutations
     def current_user
       context[:current_user]
     end
+
+    # Returns Array of errors on an ActiveRecord object
+    def errors_on_object(record)
+      record.errors.full_messages
+    end
   end
 end

app/graphql/types/award_emojis/award_emoji_type.rb

+# frozen_string_literal: true
+
+module Types
+  module AwardEmojis
+    class AwardEmojiType < BaseObject
+      graphql_name 'AwardEmoji'
+
+      authorize :read_emoji
+
+      present_using AwardEmojiPresenter
+
+      field :name,
+            GraphQL::STRING_TYPE,
+            null: false,
+            description: 'The emoji name'
+
+      field :description,
+            GraphQL::STRING_TYPE,
+            null: false,
+            description: 'The emoji description'
+
+      field :unicode,
+            GraphQL::STRING_TYPE,
+            null: false,
+            description: 'The emoji in unicode'
+
+      field :emoji,
+            GraphQL::STRING_TYPE,
+            null: false,
+            description: 'The emoji as an icon'
+
+      field :unicode_version,
+            GraphQL::STRING_TYPE,
+            null: false,
+            description: 'The unicode version for this emoji'
+
+      field :user,
+            Types::UserType,
+            null: false,
+            description: 'The user who awarded the emoji',
+            resolve: -> (award_emoji, _args, _context) {
+              Gitlab::Graphql::Loaders::BatchModelLoader.new(User, award_emoji.user_id).find
+            }
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -6,6 +6,9 @@ module Types
     graphql_name "Mutation"
+    mount_mutation Mutations::AwardEmojis::Add
+    mount_mutation Mutations::AwardEmojis::Remove
+    mount_mutation Mutations::AwardEmojis::Toggle
     mount_mutation Mutations::MergeRequests::SetWip
   end
 end

app/models/snippet.rb

@@ -194,6 +194,10 @@ class Snippet < ApplicationRecord
     'snippet'
   end
+  def to_ability_name
+    model_name.singular
+  end
+
   class << self
     # Searches for snippets with a matching title or file name.
     #

app/policies/award_emoji_policy.rb

+# frozen_string_literal: true
+
+class AwardEmojiPolicy < BasePolicy
+  delegate { @subject.awardable if DeclarativePolicy.has_policy?(@subject.awardable) }
+
+  condition(:can_read_awardable) do
+    can?(:"read_#{@subject.awardable.to_ability_name}")
+  end
+
+  rule { can_read_awardable }.enable :read_emoji
+end

app/presenters/award_emoji_presenter.rb

+# frozen_string_literal: true
+
+class AwardEmojiPresenter < Gitlab::View::Presenter::Delegated
+  presents :award_emoji
+
+  def description
+    as_emoji['description']
+  end
+
+  def unicode
+    as_emoji['unicode']
+  end
+
+  def emoji
+    as_emoji['moji']
+  end
+
+  def unicode_version
+    Gitlab::Emoji.emoji_unicode_version(award_emoji.name)
+  end
+
+  private
+
+  def as_emoji
+    @emoji ||= Gitlab::Emoji.emojis[award_emoji.name] || {}
+  end
+end

changelogs/unreleased/62826-graphql-emoji-mutations.yml

+---
+title: GraphQL mutations for add, remove and toggle emoji
+merge_request: 29919
+author:
+type: added

lib/gitlab/graphql/copy_field_description.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module CopyFieldDescription
+      extend ActiveSupport::Concern
+
+      class_methods do
+        # Returns the `description` for property of field `field_name` on type.
+        # This can be used to ensure, for example, that mutation argument descriptions
+        # are always identical to the corresponding query field descriptions.
+        #
+        # E.g.:
+        #   argument :name, GraphQL::STRING_TYPE, description: copy_field_description(Types::UserType, :name)
+        def copy_field_description(type, field_name)
+          type.fields[field_name.to_s.camelize(:lower)].description
+        end
+      end
+    end
+  end
+end

lib/gitlab/graphql/errors.rb

@@ -6,6 +6,7 @@ module Gitlab
       BaseError = Class.new(GraphQL::ExecutionError)
       ArgumentError = Class.new(BaseError)
       ResourceNotAvailable = Class.new(BaseError)
+      MutationError = Class.new(BaseError)
     end
   end
 end

spec/factories/award_emoji.rb

@@ -5,7 +5,7 @@ FactoryBot.define do
     awardable factory: :issue
     after(:create) do |award, evaluator|
-      award.awardable.project.add_guest(evaluator.user)
+      award.awardable.project&.add_guest(evaluator.user)
     end
     trait :upvote

spec/graphql/types/award_emojis/award_emoji_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe GitlabSchema.types['AwardEmoji'] do
+  it { expect(described_class.graphql_name).to eq('AwardEmoji') }
+
+  it { is_expected.to require_graphql_authorizations(:read_emoji) }
+
+  it { expect(described_class).to have_graphql_fields(:description, :unicode_version, :emoji, :name, :unicode, :user) }
+end

spec/lib/gitlab/graphql/authorize/authorize_resource_spec.rb

@@ -67,7 +67,7 @@ describe Gitlab::Graphql::Authorize::AuthorizeResource do
     end
     describe '#authorize!' do
-      it 'does not raise an error' do
+      it 'raises an error' do
         expect { loading_resource.authorize!(project) }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
       end
     end

spec/lib/gitlab/graphql/copy_field_description_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Graphql::CopyFieldDescription do
+  subject { Class.new.include(described_class) }
+
+  describe '.copy_field_description' do
+    let(:type) do
+      Class.new(Types::BaseObject) do
+        graphql_name "TestType"
+
+        field :field_name, GraphQL::STRING_TYPE, null: true, description: 'Foo'
+      end
+    end
+
+    it 'returns the correct description' do
+      expect(subject.copy_field_description(type, :field_name)).to eq('Foo')
+    end
+  end
+end

spec/policies/award_emoji_policy_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe AwardEmojiPolicy do
+  let(:user) { create(:user) }
+  let(:award_emoji) { create(:award_emoji, awardable: awardable) }
+
+  subject { described_class.new(user, award_emoji) }
+
+  shared_examples 'when the user can read the awardable' do
+    context do
+      let(:project) { create(:project, :public) }
+
+      it { expect_allowed(:read_emoji) }
+    end
+  end
+
+  shared_examples 'when the user cannot read the awardable' do
+    context do
+      let(:project) { create(:project, :private) }
+
+      it { expect_disallowed(:read_emoji) }
+    end
+  end
+
+  context 'when the awardable is an issue' do
+    let(:awardable) { create(:issue, project: project) }
+
+    include_examples 'when the user can read the awardable'
+    include_examples 'when the user cannot read the awardable'
+  end
+
+  context 'when the awardable is a merge request' do
+    let(:awardable) { create(:merge_request, source_project: project) }
+
+    include_examples 'when the user can read the awardable'
+    include_examples 'when the user cannot read the awardable'
+  end
+
+  context 'when the awardable is a note' do
+    let(:awardable) { create(:note_on_merge_request, project: project) }
+
+    include_examples 'when the user can read the awardable'
+    include_examples 'when the user cannot read the awardable'
+  end
+
+  context 'when the awardable is a snippet' do
+    let(:awardable) { create(:project_snippet, :public, project: project) }
+
+    include_examples 'when the user can read the awardable'
+    include_examples 'when the user cannot read the awardable'
+  end
+end

spec/presenters/award_emoji_presenter_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe AwardEmojiPresenter do
+  let(:emoji_name) { 'thumbsup' }
+  let(:award_emoji) { build(:award_emoji, name: emoji_name) }
+  let(:presenter) { described_class.new(award_emoji) }
+
+  describe '#description' do
+    it { expect(presenter.description).to eq Gitlab::Emoji.emojis[emoji_name]['description'] }
+  end
+
+  describe '#unicode' do
+    it { expect(presenter.unicode).to eq Gitlab::Emoji.emojis[emoji_name]['unicode'] }
+  end
+
+  describe '#unicode_version' do
+    it { expect(presenter.unicode_version).to eq Gitlab::Emoji.emoji_unicode_version(emoji_name) }
+  end
+
+  describe '#emoji' do
+    it { expect(presenter.emoji).to eq Gitlab::Emoji.emojis[emoji_name]['moji'] }
+  end
+
+  describe 'when presenting an award emoji with an invalid name' do
+    let(:emoji_name) { 'invalid-name' }
+
+    it 'returns nil for all properties' do
+      expect(presenter.description).to be_nil
+      expect(presenter.emoji).to be_nil
+      expect(presenter.unicode).to be_nil
+      expect(presenter.unicode_version).to be_nil
+    end
+  end
+end