Validate path being a list of strings

Checks whether the alert's field path is a list of strings

ee/app/models/alert_management/alert_payload_field.rb

@@ -7,9 +7,20 @@ module AlertManagement
 
     attr_accessor :project, :path, :label, :type
 
+    SUPPORTED_TYPES = %w[string numeric datetime].freeze
+
     validates :project, presence: true
-    validates :path, presence: true
     validates :label, presence: true
-    validates :type, presence: true
+    validates :type, inclusion: { in: SUPPORTED_TYPES }
+
+    validate :path_is_list_of_strings
+
+    private
+
+    def path_is_list_of_strings
+      unless path.is_a?(Array) && path.all? { |segment| segment.is_a?(String) }
+        errors.add(:path, 'must be a list of strings')
+      end
+    end
   end
 end

ee/spec/factories/alert_management/alert_payload_fields.rb

@@ -3,7 +3,7 @@
 FactoryBot.define do
   factory :alert_management_alert_payload_field, class: 'AlertManagement::AlertPayloadField' do
     project
-    path { 'title' }
+    path { ['title'] }
     label { 'Title' }
     type { 'string' }
   end

ee/spec/models/alert_management/alert_payload_field_spec.rb

@@ -3,10 +3,22 @@
 require 'spec_helper'
 
 RSpec.describe AlertManagement::AlertPayloadField do
+  let(:alert_payload_field) { build_stubbed(:alert_management_alert_payload_field) }
+
   describe 'Validations' do
     it { is_expected.to validate_presence_of(:project) }
-    it { is_expected.to validate_presence_of(:path) }
     it { is_expected.to validate_presence_of(:label) }
-    it { is_expected.to validate_presence_of(:type) }
+    it { is_expected.to validate_inclusion_of(:type).in_array(described_class::SUPPORTED_TYPES) }
+
+    describe '#path_is_list_of_strings' do
+      before do
+        alert_management_alert_payload_field.path = path
+        alert_management_alert_payload_field.valid?
+      end
+
+      context 'when path is nil'
+      context 'when path is empty array'
+      context 'when path does not contain only strings'
+    end
   end
 end