InnoViz SF Database mapper

innoviz_resource.rb

#!/usr/bin/env ruby -wKU

##
# Runtime options
#
require "optparse"

options = { :spec => false }

ARGV.options do |opts|
  opts.banner = "Usage: #{File.basename($PROGRAM_NAME)}"

  opts.on( "-s", "--[no-]spec", "Run specs") do |v|
    options[:spec] = v
  end
end.parse!

##
# Implementation
# 

require "json"

module InnoViz
  module Resource
    module ClassMethods
      def resource_name(*args)
        @resource_name = args[0] unless args.empty?
        @resource_name.to_s.split(/[ -]/).map { |w| w.capitalize }.join
      end

      def slot(name)
        self.class_eval { attr_accessor name }
        slots << name
      end

      def slots
        @slots ||= []
      end

      def resource_path
        resource_name
      end

      def resource_slots_path
        File.join(resource_path, 'slots')
      end

      def parse(data)
        obj = new
        JSON.parse(data).each do |k,v|
          obj.send "#{k}=", v
        end
        obj
      end

      def migrate
        Dir.mkdir resource_path unless File.exists?(resource_path)
        Dir.mkdir resource_slots_path unless File.exists?(resource_slots_path)
      end
    end
  
    module InstanceMethods
      alias_method :id, :object_id

      def save
        File.open("#{id}.json", "w+") { |f| f.write to_json }
      end

      def to_json
        obj = {}
        self.class.slots.each do |s|
          obj[s] = send(s)
        end
        obj.to_json
      end
    end
  
    def self.included(receiver)
      receiver.extend         ClassMethods
      receiver.send :include, InstanceMethods
    end
  end
end





##
# Specs
#
# To run the test:
#
#  %> ruby innovizdb.rb -s
#
require "minitest/spec"
require "minitest/autorun" if options[:spec]

describe "InnoViz::Resource" do
  require "tmpdir"

  def sandbox
    Dir.mktmpdir do |dir|
      Dir.chdir(dir) { yield }
    end
  end
  
  let(:resource) do
    Class.new do
      include InnoViz::Resource

      resource_name :account

      slot :name
      slot :age
    end
  end

  describe ".migrate" do
    it 'creates the correct folder name' do
      sandbox do
        resource.migrate
        File.directory?('Account').must_equal true
      end
    end

    it 'creates the slots dir' do
      sandbox do
        resource.migrate
        File.directory?('Account/slots').must_equal true
      end
    end

    it 'can be run multiple times' do
      sandbox do
        lambda { resource.migrate }.must_be_silent
        lambda { resource.migrate }.must_be_silent
        lambda { resource.migrate }.must_be_silent
      end
    end
  end

  describe "slots" do
    it 'creates a accesor for each slot' do
      obj = resource.new
      obj.must_respond_to :name=
      obj.must_respond_to :name
      obj.must_respond_to :age=
      obj.must_respond_to :age
    end
  end

  describe "#save" do
    it 'saves the instance to a file using the id as the name' do
      sandbox do
        resource.migrate

        obj = resource.new
        obj.name = "Emma"
        obj.age  = 21

        obj.save
        
        File.exists?("#{obj.id}.json").must_equal true
      end
    end

    it 'saves the instance as a json representation' do
      sandbox do
        resource.migrate

        obj = resource.new
        obj.name = "Emma"
        obj.age  = 21

        obj.save
        
        File.open("#{obj.id}.json") { |f|
          the_json = JSON.parse(f.read)
          the_json["name"].must_equal obj.name
          the_json["age"].must_equal obj.age
        }
      end
    end
  end

  describe ".parse" do
    it 'can serialize itself from a json representation' do
      obj = resource.parse(%({ "name": "Pipo", "age": 21 }))

      obj.name.must_equal "Pipo"
      obj.age.must_equal 21
    end
  end
end