Fix `errors` attribute of ScanType on GraphQL

ee/app/graphql/types/scan_type.rb

@@ -3,6 +3,8 @@
 module Types
   # rubocop: disable Graphql/AuthorizeTypes
   class ScanType < BaseObject
+    present_using ::Security::ScanPresenter
+
     graphql_name 'Scan'
     description 'Represents the security scan information'
 
@@ -10,9 +12,5 @@ module Types
 
     field :name, GraphQL::STRING_TYPE, null: false, description: 'Name of the scan.'
     field :errors, [GraphQL::STRING_TYPE], null: false, description: 'List of errors.'
-
-    def errors
-      object.info['errors'].to_a
-    end
   end
 end

ee/app/presenters/security/scan_presenter.rb

+# frozen_string_literal: true
+
+module Security
+  class ScanPresenter < Gitlab::View::Presenter::Delegated
+    ERROR_MESSAGE_FORMAT = '[%<type>s] %<message>s'
+
+    presents :scan
+
+    def errors
+      info['errors'].to_a.map { |error| format(ERROR_MESSAGE_FORMAT, error.symbolize_keys) }
+    end
+  end
+end

ee/changelogs/unreleased/fix_scan_errors_on_graphql_api.yml

+---
+title: Fix the 'errors' attribute of the 'ScanType' on GraphQL API
+merge_request: 57882
+author:
+type: fixed

ee/spec/graphql/types/scan_type_spec.rb

@@ -3,8 +3,40 @@
 require 'spec_helper'
 
 RSpec.describe GitlabSchema.types['Scan'] do
+  include GraphqlHelpers
+
   let(:fields) { %i(name errors) }
 
   it { expect(described_class).to have_graphql_fields(fields) }
   it { expect(described_class).to require_graphql_authorizations(:read_scan) }
+
+  describe 'field values' do
+    let_it_be(:build) { create(:ee_ci_build, :dast, name: 'foo') }
+    let_it_be(:security_scan) { build.security_scans.first }
+    let_it_be(:user) { create(:user) }
+
+    subject { resolve_field(field_name, security_scan, current_user: user) }
+
+    before do
+      stub_licensed_features(security_dashboard: true)
+
+      build.project.add_developer(user)
+    end
+
+    describe 'name' do
+      let(:field_name) { :name }
+
+      it { is_expected.to eq('foo') }
+    end
+
+    describe 'errors' do
+      let(:field_name) { :errors }
+
+      before do
+        security_scan.update!(info: { 'errors' => [{ 'type' => 'foo', 'message' => 'bar' }] })
+      end
+
+      it { is_expected.to eq(['[foo] bar']) }
+    end
+  end
 end

ee/spec/presenters/security/scan_presenter_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Security::ScanPresenter do
+  let(:presenter) { described_class.new(security_scan) }
+  let(:security_scan) { build_stubbed(:security_scan, info: { 'errors' => [{ 'type' => 'foo', 'message' => 'bar' }] }) }
+
+  describe '#errors' do
+    subject { presenter.errors }
+
+    it { is_expected.to eq(['[foo] bar']) }
+  end
+end