The 19 year old gem. This dog can still hunt!
To execute the script, download the demo.rb file locally and execute it with the ruby command:
ruby demo.rbThe script will execute, and the test suite will pass.
To experiment with different tests at different points in time, insert binding.irb commands to pause execution.
There have been recent improvements:
There are some still some proposed improvements:
( 🤞 )
| require "bundler/inline" | |
| gemfile(true) do | |
| source "https://rubygems.org" | |
| gem "activeresource", github: "rails/activeresource" | |
| gem "rails" | |
| gem "sqlite3" | |
| end | |
| require "active_record/railtie" | |
| require "minitest/autorun" | |
| # This connection will do for database-independent bug reports. | |
| ENV["DATABASE_URL"] = "sqlite3::memory:" | |
| class DemoApp < Rails::Application | |
| config.load_defaults Rails::VERSION::STRING.to_f | |
| config.eager_load = false | |
| config.logger = Logger.new($stdout) | |
| config.secret_key_base = "secret_key_base" | |
| config.active_record.encryption.primary_key = "primary_key" | |
| config.active_record.encryption.deterministic_key = "deterministic_key" | |
| config.active_record.encryption.key_derivation_salt = "key_derivation_salt" | |
| end | |
| Rails.application.initialize! | |
| ActiveRecord::Schema.define do | |
| create_table :posts, force: true do |t| | |
| t.json :cms_post, null: false | |
| t.virtual :cms_post_id, type: :string, stored: true, null: false, as: <<~SQL | |
| cms_post ->> 'id' | |
| SQL | |
| t.index :cms_post_id, unique: true | |
| end | |
| end | |
| module Cms | |
| class UrlEncodedFormat | |
| include ActiveResource::Formats::UrlEncodedFormat | |
| def initialize(&transform) | |
| @transform = transform | |
| end | |
| def encode(params, options = nil) | |
| params = params.deep_transform_keys(&@transform) | |
| super | |
| end | |
| end | |
| class ApplicationResource < ActiveResource::Base | |
| self.site = "https://cms.dev" | |
| self.query_format = UrlEncodedFormat.new { |key| key.to_s.camelcase(:lower) } | |
| end | |
| class Post < ApplicationResource | |
| schema do | |
| attribute :name, :string | |
| attribute :body, :string | |
| end | |
| end | |
| end | |
| class Post < ActiveRecord::Base | |
| serialize :cms_post, coder: ActiveResource::Coder.new(Cms::Post, :serializable_hash) | |
| delegate_missing_to :cms_post | |
| end | |
| require "rails/test_help" | |
| class PostTest < ActiveSupport::TestCase | |
| test "GET find interface" do | |
| ActiveResource::HttpMock.respond_to.get "/posts/abc123.json", {}, { | |
| id: "abc123", name: "Hello World", body: "From the API", created_on: "2025-11-14" | |
| }.to_json | |
| resource = Cms::Post.find("abc123") | |
| assert_kind_of Cms::Post, resource | |
| assert_equal "abc123", resource.id | |
| assert_equal "Hello World", resource.name | |
| assert_equal "From the API", resource.body | |
| assert_equal "2025-11-14", resource.created_on | |
| end | |
| test "GET query param interface" do | |
| ActiveResource::HttpMock.respond_to.get "/posts.json?sortBy=created_at", {}, [ | |
| { id: "abc123", name: "Hello World", created_at: 10.minutes.ago }, | |
| { id: "def456", name: "Hello Rails", created_at: 5.minutes.ago } | |
| ].to_json | |
| resources = Cms::Post.where(sort_by: "created_at") | |
| assert_equal [ "Hello World", "Hello Rails" ], resources.map(&:name) | |
| end | |
| test "POST can map response with Errors to " do | |
| ActiveResource::HttpMock.respond_to.post "/posts.json" do | |
| response = { errors: [ "Name is taken" ] } | |
| ActiveResource::Response.new(response.to_json, 422) | |
| end | |
| resource = Cms::Post.new(name: "Let's Not") | |
| assert_raises ActiveResource::ResourceInvalid do | |
| resource.save! | |
| end | |
| assert_equal [ "is taken" ], resource.errors[:name] | |
| end | |
| test "stores Cms::Post instances as JSON" do | |
| cms_post = Cms::Post.new id: "abc123", name: "Hello", body: "World" | |
| Post.create!(cms_post:) | |
| # queries by synthesized column | |
| post = Post.find_by! cms_post_id: cms_post.id | |
| # uniqueness constraints enforced on synthesized column | |
| assert_raises(ActiveRecord::RecordNotUnique) { Post.create!(cms_post:) } | |
| # reads column to object instance | |
| assert_kind_of Cms::Post, post.cms_post | |
| assert_equal cms_post, post.cms_post | |
| # access through instance | |
| assert_equal cms_post.id, post.cms_post.id | |
| assert_equal cms_post.name, post.cms_post.name | |
| assert_equal cms_post.body, post.cms_post.body | |
| # access through delegation | |
| assert_equal cms_post.name, post.name | |
| assert_equal cms_post.body, post.body | |
| # virtual column access synthesized from JSON | |
| assert_equal cms_post.id, post.cms_post_id | |
| end | |
| test "Post can reload Cms::Post instance" do | |
| ActiveResource::HttpMock.respond_to.get "/posts/abc123.json", {}, { | |
| id: "abc123", name: "Goodbye" | |
| }.to_json | |
| cms_post = Cms::Post.new id: "abc123", name: "Hello" | |
| post = Post.create!(cms_post:) | |
| assert_changes -> { post.reload.name }, from: "Hello", to: "Goodbye" do | |
| post.cms_post.reload | |
| post.save! | |
| end | |
| end | |
| end |