Service Oriented Design with Ruby and Rails (examples that actually work)

Rakefile

require 'rubygems'
require 'active_record'
require 'sinatra'
require 'models/user'
require 'logger'

env_index = ARGV.index("-e")
env_arg = ARGV[env_index+1] if env_index
env = env_arg || ENV["SINATRA_ENV"] || "development"
databases = YAML.load_file("config/database.yml")
SINATRA_LOGGER = Logger.new(File.open("log/#{env}.log", "w+"))
ActiveRecord::Base.logger = SINATRA_LOGGER
ActiveRecord::Base.establish_connection(databases[env])
ActiveRecord::Base.include_root_in_json = false # don't include "user: {...}"

# HTTP entry points
# get a user by name
get '/api/v1/users/:name' do
  user = User.find_by_name(params[:name])
  if user
    user.to_json
  else
    error 404, {:error => "user not found"}.to_json
  end
end

post '/api/v1/users' do
  begin
    user = User.create(JSON.parse(request.body.read))
    if user.valid?
      user.to_json
    else
      error 400, user.errors.to_json
    end
  rescue => e
    error 400, e.message.to_json
  end
end

service.rb

require 'rubygems'
require 'active_record'
require 'sinatra'
require 'models/user'
require 'logger'

env_index = ARGV.index("-e")
env_arg = ARGV[env_index+1] if env_index
env = env_arg || ENV["SINATRA_ENV"] || "development"
databases = YAML.load_file("config/database.yml")
SINATRA_LOGGER = Logger.new(File.open("log/#{env}.log", "w+"))
ActiveRecord::Base.logger = SINATRA_LOGGER
ActiveRecord::Base.establish_connection(databases[env])
ActiveRecord::Base.include_root_in_json = false # don't include "user: {...}"

# HTTP entry points
# get a user by name
get '/api/v1/users/:name' do
  user = User.find_by_name(params[:name])
  if user
    user.to_json
  else
    error 404, {:error => "user not found"}.to_json
  end
end

# create a new user
post '/api/v1/users' do
  begin
    user = User.create(JSON.parse(request.body.read))
    if user.valid?
      user.to_json
    else
      error 400, user.errors.to_json
    end
  rescue => e
    error 400, e.message.to_json
  end
end

# update an existing user
put '/api/v1/users/:name' do
  user = User.find_by_name(params[:name])
  if user
    begin
      if user.update_attributes(JSON.parse(request.body.read))
        user.to_json
      else
        error 400, user.errors.to_json
      end
    rescue => e
      error 400, e.message.to_json
    end
  else
    error 404, {:error => "user not found"}.to_json
  end
end

# destroy an existing user
delete '/api/v1/users/:name' do
  user = User.find_by_name(params[:name])
  if user
    user.destroy
    user.to_json
  else
    error 404, {:error => "user not found"}.to_json
  end
end

service_spec.rb

require File.dirname(__FILE__) + "/../service"
require 'rspec' # 'spec' is now 'rspec'; JE
# require 'spec/interop/test' # I have no idea what this was, but it won't work now; JE
require 'rack/test'

set :environment, :test
# Test::Unit::TestCase.send :include, Rack::Test::Methods # this is old; JE

# Do this instead of TestCase.send :include, ...; JE
RSpec.configure do |conf|
  conf.include Rack::Test::Methods
end

def app
  Sinatra::Application
end

describe "service" do
  before(:each) do
    User.create(
      :name => "paul",
      :email => "paul@pauldix.net",
      :password => "strongpass",
      :bio => "rubyist")
  end
  # the User.create will only work the first time, so empty out the database after
  # each test; JE
  after(:each) do
    User.delete_all
  end
  it "should return a user by name" do
    get '/api/v1/users/paul'
    last_response.should be_ok
    attributes = JSON.parse(last_response.body)
    attributes["name"].should == "paul"
  end
  it "should return a user with an email" do
    get '/api/v1/users/paul'
    last_response.should be_ok
    attributes = JSON.parse(last_response.body)
    attributes["email"].should == "paul@pauldix.net"
  end
  it "should not return a user's password" do
    get '/api/v1/users/paul'
    last_response.should be_ok
    attributes = JSON.parse(last_response.body)
    attributes.should_not have_key("password")
  end
  it "should return a user with a bio" do
    get '/api/v1/users/paul'
    last_response.should be_ok
    attributes = JSON.parse(last_response.body)
    attributes["bio"].should == "rubyist"
  end
  it "should return a 404 for users that don't exist" do
    get '/api/v1/users/foo'
    last_response.status.should == 404
  end
end

describe "POST on /api/v1/users" do
  it "should create a user" do
    User.transaction do # wrap this in a transaction so other users can be created; JE
      num_users = User.count
      post '/api/v1/users', {
        :name => "trotter",
        :email => "no spam",
        :password => "whatever",
        :bio => "southern belle"}.to_json
      last_response.should be_ok
      User.count.should == num_users+1
      # Don't do another test on GET, we spec'd that above; JE
      raise ActiveRecord::Rollback # rollback the transaction; JE
    end
  end
end

describe "PUT on /api/v1/users/:name" do # we're using :name, not :id; JE
  it "should update a user" do
    User.transaction do # wrap this in a transaction so other users can be created; JE
      u = User.create(
        :name => "bryan",
        :email => "no spam",
        :password => "whatever",
        :bio => "rspec master")
      put '/api/v1/users/bryan', {:bio => "testing freak"}.to_json
      last_response.should be_ok
      get '/api/v1/users/bryan'
      attributes = JSON.parse(last_response.body)
      attributes["bio"].should == "testing freak"
      raise ActiveRecord::Rollback # rollback the transaction; JE
    end
  end
end

describe "DELETE on /api/v1/users/:id" do
  it "should delete a user" do
    User.transaction do # wrap this in a transaction so other users can be created; JE
      User.create(
        :name => "francis",
        :email => "no spam",
        :password => "whatever",
        :bio => "williamsburg hipster")
      delete '/api/v1/users/francis'
      last_response.should be_ok
      get '/api/v1/users/francis'
      last_response.status.should == 404
      raise ActiveRecord::Rollback # rollback the transaction; JE
    end
  end
end

This helped me out a lot. Thanks