dbexpect

dbexpect

dbexpect is a domain specific language written in ruby for testing ETL solutions.

Taking cues from Rspec in structure and usage, the point is to enable the specification of unit test data, job running, and expected outcomes for an entity/test cases in a ruby file using an internal DSL that is targeted at this kind of testing.

dbexpect is ideally suited to creating automated unit tests for individual ETL jobs in a data warehousing or data migration project. Helping to ensure correctness of the job initially developed, and catching problems later on when someone makes a change that could affect existing functionality.

Sample test

describe "Moving customers from source to target" do
  @src = table(:dbexpect_src,:dbexpect_src,:customers_src)
  @tgt = table(:dbexpect_tgt,:dbexpect_tgt,:customers_tgt)

  etl_run_command "ruby etl2.rb"

  expect_total_rows @tgt, 1

  describe "it should upcase customer names" do
    insert_into @src,
      [:id,:name],
      [[1,"Fred"]]

    expect_rows @tgt,
      [:id,:name],
      [[1,"FRED"]]
  end

  describe "it should not migrate smith (because screw that guy)" do
    insert_into @src,
      [:id,:name],
      [[1,"Smith"]]

    # expect no rows
  end
end

Installation

gem install dbexpect

Create a database.yml file in a folder where you want to store your tests, and set up connections for each of the databases you want dbexpect to talk to. Each of the connections will need to have an ODBC connection defined as well.

database.yml:

database1:
  database: odbc_dsn
  username: barry
  password: secret

database2:
  database: odbc_dsn2
  username: shaz
  password: secret

Usage

Assuming a folder structure for your tests that looks like this:

/
|-database.yml
|
|- defaults/
|          |- defaults_for_tablex.rb
|
|- tests/
        |- test1.rb
        |- test2.rb

To run the tests in test1.rb:

prompt:/$ dbexpect tests/test1.rb

There is a sample dbexpect project at http://github.com/C3/dbexpect_example for more information.

License

Copyright 2012 C3 Business Solutions. See COPYING for further details.

dbexpect is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

dbexpect is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with dbexpect. If not, see http://www.gnu.org/licenses/.