Add Attributes Concern with flex_attribute method and memorable_date type (#42)

- Add Flex::Attributes Concern that defines flex_attribute class method
- Add memorable_date type to flex_attribute options
- Add tests to test the ability to convert

Author: lorenyu

template/{{app_name}}/engines/flex/app/lib/flex/attributes.rb

@@ -0,0 +1,89 @@
+module Flex
+  module Attributes
+    extend ActiveSupport::Concern
+
+    # This class defines a string that represents a date in the format "<YEAR>-<MM>-<DD>"
+    # and is designed to also allow invalid dates such as "2020-13-32" to facilitate
+    # storing user input before validation.
+    # Validation is handled separately to ensure that the date is valid
+    #
+    # The class also has nested attributes for year, month, and day to facilitate
+    # treating the date as a structured value object which is useful for form building.
+    class DateString < ::String
+      attr_reader :year, :month, :day
+
+      def initialize(year, month, day)
+        @year, @month, @day = year, month, day
+        super("#{year}-#{month.rjust(2, "0")}-#{day.rjust(2, "0")}")
+      end
+    end
+
+    # A custom ActiveRecord type that allows storing a date as a string.
+    # The attribute accepts a Date, a Hash with keys :year, :month, :day,
+    # or a String in the format "YYYY-MM-DD".
+    class DateStringType < ActiveRecord::Type::String
+      # Accept a Date, a Hash of with keys :year, :month, :day,
+      # or a String in the format "YYYY-MM-DD"
+      # (the parts of the string don't have to be numeric or represent valid years/months/days
+      # since the date will be validated separately)
+      def cast(value)
+        return nil if value.nil?
+
+        year, month, day = case value
+        when Date
+          [ value.year.to_s, value.month.to_s, value.day.to_s ]
+        when Hash
+          [ value[:year].to_s, value[:month].to_s, value[:day].to_s ]
+        when String
+          if match = value.match(/(\w+)-(\w+)-(\w+)/)
+            match.captures
+          else
+            raise ArgumentError, "Invalid date string format: #{value.inspect}. Expected format is '<YEAR>-<MONTH>-<DAY>'."
+          end
+        else
+          raise ArgumentError, "Invalid value for #{name}: #{value.inspect}. Expected Date, Hash, or String."
+        end
+
+        DateString.new(year, month, day)
+      end
+
+      def type
+        :date_string
+      end
+    end
+
+    class_methods do
+      def flex_attribute(name, type, options = {})
+        if type == :memorable_date
+          memorable_date_attribute name, options
+        else
+          raise ArgumentError, "Unsupported attribute type: #{type}"
+        end
+      end
+
+      private
+
+        def memorable_date_attribute(name, options)
+          attribute name, DateStringType.new
+
+          validate :"validate_#{name}"
+
+          if options[:presence]
+            validates name, presence: true
+          end
+
+          # Create a validation method that checks if the value is a valid date
+          define_method "validate_#{name}" do
+            value = send(name)
+            return if value.nil?
+
+            begin
+              Date.strptime(value, "%Y-%m-%d")
+            rescue Date::Error
+              errors.add(name, :invalid_date, message: "is not a valid date")
+            end
+          end
+        end
+    end
+  end
+end

template/{{app_name}}/engines/flex/spec/dummy/app/models/passport_application_form.rb

@@ -1,9 +1,12 @@
 class PassportApplicationForm < Flex::ApplicationForm
+  include Flex::Attributes
+
   before_create :create_passport_case, unless: -> { has_case_id? }
 
   attribute :first_name, :string
   attribute :last_name, :string
-  attribute :date_of_birth, :date
+
+  flex_attribute :date_of_birth, :memorable_date
 
   attribute :case_id, :integer
   private def case_id=(value)

template/{{app_name}}/engines/flex/spec/dummy/spec/lib/flex/attributes_spec.rb

@@ -0,0 +1,72 @@
+require "rails_helper"
+
+RSpec.describe Flex::Attributes do
+  before do
+    test_model = Class.new do
+      include ActiveModel::Attributes
+      include ActiveModel::Validations
+      include Flex::Attributes
+
+      flex_attribute :test_date, :memorable_date
+    end
+    stub_const "TestModel", test_model
+  end
+
+  let(:object) { TestModel.new }
+
+  describe "memorable_date attribute" do
+    it "allows setting a Date" do
+      object.test_date = Date.new(2020, 1, 2)
+      expect(object.test_date).to eq("2020-01-02")
+      expect(object.test_date.year).to eq("2020")
+      expect(object.test_date.month).to eq("1")
+      expect(object.test_date.day).to eq("2")
+    end
+
+    [
+      [ { year: 2020, month: 1, day: 2 }, "2020-01-02", "2020", "1", "2" ],
+      [ { year: "2020", month: "1", day: "2" }, "2020-01-02", "2020", "1", "2" ],
+      [ { year: "2020", month: "01", day: "02" }, "2020-01-02", "2020", "01", "02" ],
+      [ { year: "badyear", month: "badmonth", day: "badday" }, "badyear-badmonth-badday", "badyear", "badmonth", "badday" ]
+    ].each do |input_hash, expected, expected_year, expected_month, expected_day|
+      it "allows setting a Hash with year, month, and day [#{expected}]" do
+        object.test_date = input_hash
+        expect(object.test_date).to eq(expected)
+        expect(object.test_date.year).to eq(expected_year)
+        expect(object.test_date.month).to eq(expected_month)
+        expect(object.test_date.day).to eq(expected_day)
+      end
+    end
+
+    [
+      [ "2020-1-2", "2020-01-02", "2020", "1", "2" ],
+      [ "2020-01-02", "2020-01-02", "2020", "01", "02" ],
+      [ "badyear-badmonth-badday", "badyear-badmonth-badday", "badyear", "badmonth", "badday" ]
+    ].each do |input_string, expected, expected_year, expected_month, expected_day|
+      it "allows setting string in format <YEAR>-<MONTH>-<DAY> [#{expected}]" do
+        object.test_date = input_string
+        expect(object.test_date).to eq(expected)
+        expect(object.test_date.year).to eq(expected_year)
+        expect(object.test_date.month).to eq(expected_month)
+        expect(object.test_date.day).to eq(expected_day)
+      end
+    end
+
+    [
+      { year: 2020, month: 1, day: -1 },
+      { year: 2020, month: 1, day: 0 },
+      { year: 2020, month: 1, day: 32 },
+      { year: 2020, month: -1, day: 1 },
+      { year: 2020, month: 0, day: 1 },
+      { year: 2020, month: 13, day: 1 },
+      { year: 2020, month: 2, day: 30 }
+    ].each do |date|
+      it "validates that date is a valid date" do
+        object.test_date = date
+        expect(object.test_date).to eq("%04d-%02d-%02d" % [ date[:year], date[:month], date[:day] ])
+        expect(object).not_to be_valid
+        expect(object.errors["test_date"]).to include("is not a valid date")
+      end
+    end
+  end
+end

template/{{app_name}}/engines/flex/spec/dummy/spec/models/flex/passport_application_form_spec.rb

@@ -21,6 +21,20 @@ def generate_random_date_of_birth
         passport_application_form.save!
       end
 
+      describe "saving and loading" do
+        it "saves the form with valid attributes" do
+          expect(passport_application_form).to be_valid
+          expect(passport_application_form).to be_persisted
+        end
+
+        it "loads the form with correct attributes" do
+          loaded_form = described_class.find(passport_application_form.id)
+          expect(loaded_form.first_name).to eq("John")
+          expect(loaded_form.last_name).to eq("Doe")
+          expect(loaded_form.date_of_birth).to eq(passport_application_form.date_of_birth)
+        end
+      end
+
       context "when attempting to update case_id" do
         it "prevents direct status updates when setting status directly" do
           expect { passport_application_form.case_id = 22 }.to raise_error(NoMethodError)