ActiveCucumber

High-level Cucumber helpers for testing ActiveRecord-based database applications using Cucumber tables.

Verifying database records

ActiveCucumber allows to compare ActiveRecord objects against Cucumber tables, with the differences visualized intuitively as a Cucumber table diff. Only the attributes provided in the table are compared, the ones not listed are ignored.

diff_one!

ActiveCucumber.diff_one! compares the given ActiveRecord entry with the given vertical Cucumber table. These tables have their headers on the left side, and are used to describe a single record in greater detail.

When loading the last Star Trek TNG episode
Then it returns this episode:
  | SHOW | Star Trek TNG   |
  | NAME | All Good Things |
  | YEAR | 1994            |

The Then step is easy to implement with ActiveCucumber:

Then /^it returns this episode:$/ do |table|
  # @episode contains one loaded entry
  ActiveCucumber.diff_one! @episode, table
end

diff_all!

ActiveCucumber.diff_all! verifies that the given horizontal Cucumber table describes all existing database entries of the given class. Horizontal Cucumber tables have their headers on top, and define several records at once:

When I run the importer script with parameter "count=3"
Then the database contains these episodes:
  | SHOW          | NAME                  | YEAR |
  | Star Trek TNG | Encounter at Farpoint | 1987 |
  | Star Trek TNG | The Nth Degree        | 1991 |
  | Star Trek TNG | All Good Things       | 1994 |

The last step would be implemented as:

Then /^Then the database contains these episodes:$/ do |table|
  ActiveCucumber.diff_all! Episode, table
end

The Cucumber table should list the entries sorted by created_at timestamp.

Cucumberators

ActiveCucumber converts the database records into a data table and matches it against the given Cucumber table.

By default, all attributes are converted into a String. It is possible to customize this conversion step by creating a Cucumberator (short for Cucumber Decorator). This class decorates an ActiveRecord instance, and defines converters for attribute values into the format used in the Cucumber table.

class EpisodeCucumberator < Cucumberator

  # In the SHOW column, print the name of the associated show object,
  # truncated to 10 characters
  def value_of_show
    show.name.truncate 10
  end

end

ActiveCucumber automatically finds and uses these Cucumberators if this naming convention is followed.