A program that demonstrates a Scala program calling a standard JRuby/Rails ActiveRecord model object which uses a postgres database. Implement unit tests on the scala program to test the functionality. The calling interface will be the java JSR 223 Scripting API’s.

1. Submission

   1. Work will start by forking the project

      1. post any questions as issues here

   2. Submit work by issuing a git pull request

   3. Requirements can be verified by following these steps on a test machine:

      2. install software prerequisites

      3. do a git clone/git pull

      4. (optionally) creating an empty database

      5. running ‘sbt publish-local’ or ‘mvn install’ to run all tests

      6. inspecting the code

   4. Submission is accepted by accepting the pull request

   5. Submission is rejected by opening a ticket in the developers fork on github

2. Supported platforms

   6. Either of Apple OSX 10.8.2 or Ubuntu 12.04.3 LTS

3. Software Versions

   7. Maven 3.0.3 or higher (if used)

   8. Java 1.7.0_x (Oracle java SE)

   9. Jruby 1.7.3 or higher

   10. Rails 4.0.1 or higher

   11. SBT 0.13.0 or higher

   12. Scala 2.10.2 or higher

   13. Postgresql 9.2.2.0 or higher

4. Software Prerequisites

   14. Assume that the above software versions are already installed on the test machine

   15. Assume the default ‘empty’ postgresql user

5. Directory Structure scala-jruby-activerecord/ .gitignore README.md pom.xml or sbt project/ (to build,test,package the whole project) model-gem/ (a gem following the ‘bundle gem’ convention) scala-client/ (a scala project following sbt or maven convention) .../resources/ config.__ - a config file holding the db credentials

6. Packaging

   16. Project will package as:

       7. com.drsquidop.scala-jruby-activerecord:model-gem-1.0.SNAPSHOT:jar

          1. this gem will package as both a gem and a jar

       8. com.drsquidop.scala-jruby-activerecord:scala-client-1.0.SNAPSHOT:jar

          2. this jar will include a dependency on the model-gem jar

7. General Requirements

   17. scala-client

       9. based on scala 2.10 maven or sbt convention

       10. depends on model-gem jar

       11. calls model-gem using JSR 223 Scripting API (see references)

       12. passes database configuration to model-gem

       13. contains MyModel case class with these fields

           3. id: Option[Int]

           4. name: String

       14. contains Client object with these methods

           5. new(MyModel): Try[MyModel] - returns with assigned id

           6. get(id:Int): Try[MyModel] - returns record with id

           7. all(): Try[List[MyModel]] - returns all records

       15. contains ValidationException extends Exception that contains ActiveRecord generated validation errors

   18. model-gem

       16. based on ‘bundle gem ’ convention

       17. based on rails ActiveRecord model object convention

       18. passed its database configuration from scala-client

       19. contains MyGemModel ActiveRecord object with

           8. id - autoassigned pk

           9. name - string

       20. ‘mvn package’ (or shell script) handles

           10. reloading db from migrations

           11. running rspec

           12. packaging as gem

           13. packaging as jar

           14. deploying jar to local repo

8. Tests

   19. Scala tests will use ScalaTest or Specs2

   20. Unit Tests

       21. model-gem

           15. Configuration

               1. tests are implemented in rspec

               2. database configuration comes from gem/config/database.yml

           16. Test cases

               3. MyGemModel.new with (any string) creates a record in the database

               4. MyGemModel.new with (blank string) returns rails standard validation error

               5. MyGemModel.get(id) returns a valid object

               6. MyGemModel.all returns multiple entries

       22. scala-client

           17. Configuration

               7. model-gem is packaged as a jar

               8. scala-client includes model-gem jar as dependency

               9. tests run under scala-client using mvn or sbt

               10. tests are written in scalatest or specs2

               11. database config comes from scala-client/...config file

           18. Test cases

               12. Client.new(any string) returns Success(MyModel)

               13. Client.new(empty string) returns Failure(ValidationException) with ActiveRecord validation error map

               14. Client.get(valid id) returns Success(MyModel)

               15. Client.get(invalid id) returns Failure(Exception("MyModel not found"))

               16. Client.all returns Success(List[MyModel]) with several records

1. JSR 223 - http://www.oracle.com/technetwork/articles/dsl/jruby-141877.html#ej

2. Related examples:

   1. https://github.com/jruby/jruby/wiki/JRubyAndJavaCodeExamples

   2. https://kenai.com/projects/jruby/pages/WalkthroughsAndTutorials

   3. http://java.ociweb.com/mark/programming/ActiveRecord.html