Add new validator for all elements of an array

app/validators/array_validator.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class ArrayValidator < ActiveModel::EachValidator
+  # Taken from https://gist.github.com/justalever/73a1b36df8468ec101f54381996fb9d1
+
+  def validate_each(record, attribute, values)
+    Array(values).each do |value|
+      options.each do |key, args|
+        validator_options = {attributes: attribute}
+        validator_options.merge!(args) if args.is_a?(Hash)
+
+        next if value.nil? && validator_options[:allow_nil]
+        next if value.blank? && validator_options[:allow_blank]
+
+        validator_class_name = "#{key.to_s.camelize}Validator"
+        validator_class = begin
+          validator_class_name.constantize
+        rescue NameError
+          "ActiveModel::Validations::#{validator_class_name}".constantize
+        end
+
+        validator = validator_class.new(validator_options)
+        validator.validate_each(record, attribute, value)
+      end
+    end
+  end
+end