add base generators

README.md

@@ -55,6 +55,21 @@ Or install it yourself as:
 $ gem install request_migrations
 ```
 
+Next, you need to run generator:
+
+```bash
+$ rails generate request_migrations:install # --api_version 1.1 --api_prev_version 1.0 # or -v 1.1 -pv 1.0
+```
+
+This will generate the initializer file `request_migrations.rb` under `initializers` folder, and BaseMigration file `base_migration.rb` under `app/migrations/` folder as it's recommended folder for migrations files.
+
+Also, you can add more migration files using
+
+
+```bash
+$  rails generate request_migrations:migration user # --actions create update --description "doing some data migration" or -a create update -d "doing some data migration" 
+```
+
 ## Supported Rubies
 
 **`request_migrations` supports Ruby 3.1 and above.** We encourage you to upgrade if you're on an older

lib/generators/request_migrations/install_generator.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'rails/generators'
+
+module RequestMigrations
+  # Intial Files Generator class
+  class InstallGenerator < Rails::Generators::Base
+    namespace 'request_migrations:install'
+
+    desc 'Generates a request_migrations initializer configuration plus a base migration file.'
+
+    source_root File.expand_path('templates', __dir__)
+
+    class_option :api_version, type: :string, aliases: '-v', default: '1.1', desc: 'API current version'
+    class_option :api_prev_version, type: :string, aliases: '-pv', default: '1.0', desc: 'API previoues version'
+
+    def copy_base_file
+      copy_file '../../templates/base_migration.rb', 'app/migrations/base_migration.rb'
+    end
+
+    def create_initializer
+      @version = options[:api_version] || '1.1'
+      @prev_version = options[:api_prev_version] || '1.0'
+
+      template '../../templates/request_migrations.rb', 'config/initializers/request_migrations.rb'
+    end
+  end
+end

lib/generators/request_migrations/migration_generator.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'rails/generators'
+
+module RequestMigrations
+  # A default migration generator class
+  class MigrationGenerator < Rails::Generators::NamedBase
+    namespace 'request_migrations:migration'
+
+    ACTIONS = %w[index show create update delete].freeze
+    DESCRIPTION = 'description goes here'
+
+    source_root File.expand_path('../templates', __dir__)
+
+    class_option :actions, aliases: '-a', type: :array,
+                           desc: "Select specific actions to generate (#{ACTIONS.join(', ')})"
+
+    class_option :description, aliases: '-d', type: :string,
+                               desc: 'Add migration description'
+
+    def start
+      @actions = options[:actions] || ACTIONS
+      @description = options[:description] || DESCRIPTION
+
+      template 'migration.rb', "app/migrations/#{file_name}_migration.rb"
+    end
+  end
+end

lib/generators/templates/base_migration.rb.tt

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class BaseMigration < RequestMigrations::Migration
+  # Provide a useful description of the change
+  # description %(description goes here)
+
+  # Migrate inputs that contain a resource. The migration should mutate
+  # the input, whatever that may be.
+  # Replace resource below with the correct resource name, for eg: user
+  # migrate if: -> data { data in type: 'resource' } do |data|
+    # Mutate resource data
+    # Check link for more details https://github.com/keygen-sh/request_migrations#usage
+  # end
+
+  # Migrate the response. This is where you provide the migration input.
+  # Replace api/v1/resources below with the correct endpoint name, for eg: api/v1/users
+  # response if: -> res { res.successful? && res.request.params in controller: 'api/v1/resources',
+                                                                #  action: 'show' } do |res|
+    # data = JSON.parse(res.body, symbolize_names: true)
+
+    # Call our migrate definition above
+    # migrate!(data)
+
+    # res.body = JSON.generate(data)
+  # end
+end

lib/generators/templates/migration.rb.tt

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class class <%= file_name.singularize.camelize %>Migration < RequestMigrations::Migration
+  # Provide a useful description of the change
+  description %(<%= @description %>)
+
+  # Migrate inputs that contain a resource_name. The migration should mutate
+  # the input, whatever that may be.
+  migrate if: -> data { data in type: 'resource_name' } do |data|
+    data[:key] = "value"
+  end
+
+  response if: -> res { res.request.params in action: <%= @actions.map{ |action| "'#{action}'" }.join(' | ') %> } do |res|
+    data = JSON.parse(res.body, symbolize_names: true)
+
+    # Call our migrate definition above
+    migrate!(data)
+
+    res.body = JSON.generate(data)
+  end
+end

lib/generators/templates/request_migrations.rb.tt

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+RequestMigrations.configure do |config|
+  # Define a resolver to determine the target version. Here, you can perform
+  # a lookup on the current user using request parameters, or simply use
+  # a header like we are here, defaulting to the latest version.
+  config.request_version_resolver = -> request {
+    # request.headers.fetch('Foo-Version') { config.current_version }
+  }
+
+  # Define the latest version of our application.
+  config.current_version = <%= @version %>
+
+  # Define previous versions and their migrations, in descending order.
+  config.versions = {
+    '<%= @prev_version %>' => %i[base_migration]
+  }
+end

request_migrations.gemspec

@@ -18,4 +18,5 @@ Gem::Specification.new do |spec|
   spec.add_dependency "semverse", "~> 3.0"
 
   spec.add_development_dependency "rspec-rails"
+  spec.add_development_dependency "generator_spec"
 end

spec/generators/install_generator_spec.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'generator_spec/test_case'
+require 'generators/request_migrations/install_generator'
+
+RSpec.describe RequestMigrations::InstallGenerator, type: :generator do
+  include GeneratorSpec::TestCase
+
+  destination File.expand_path('tmp', __dir__)
+
+  after do
+    prepare_destination # cleanup the tmp directory
+  end
+
+  before do
+    prepare_destination
+    run_generator
+  end
+
+  it 'generates app/migrations/base_migration.rb' do
+    assert_file('app/migrations/base_migration.rb')
+  end
+
+  it 'generates config/initializers/request_migrations.rb' do
+    assert_file('config/initializers/request_migrations.rb')
+  end
+end

spec/generators/migration_generator_spec.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'generator_spec/test_case'
+require 'generators/request_migrations/migration_generator'
+
+RSpec.describe RequestMigrations::MigrationGenerator, type: :generator do
+  include GeneratorSpec::TestCase
+
+  let(:file_name) { 'file_name' }
+
+  destination File.expand_path('tmp', __dir__)
+
+  after do
+    prepare_destination # cleanup the tmp directory
+  end
+
+  before do
+    prepare_destination
+    run_generator [file_name]
+  end
+
+  it 'generates app/migrations/#{file_name}_migration.rb' do
+    assert_file("app/migrations/#{file_name}_migration.rb")
+  end
+end