Factoring steps

[vincent-lg]

Hello everyone,

I'm new to Cabbage and really like the tool. Using BDD alone never seemed that useful, until now, and doing so in Elixir with Cabbage doesn't sound too complicated, for which I am grateful.

I'm considering the possibility of using (or re-using) the same operations in different steps. I like to keep things organized and well delimited. My specific use case is to create a TCP server, connects to it and send commands. This is a common use case, but I have many sub-cases where I want to apply different files, connect, enter a command, see the result, test its output. In other words, I might have different features and different files, but I'd like to keep some common operations (connect, send a command, watch output).

As far as I can tell, for the time being, a feature (.exs) requires one and only one feature file. So this idea doesn't seem possible at the time. I could, of course, easily replicate it with helper functions to do what I want and copy/paste these 3 lines for each feature file. It won't be too hard. But it doesn't feel that great either.

Possible solutions

The first and perhaps the most simple: remove the link between test files (.exs) and the feature file (.feature). Upon executing a .exs file, all features matching the keywords in this file should execute. But I realize that, since Cabbage compiles each .exs file to a test, this might not work.

An alternative would be to allow to specify several files. Something like:

defmodule MyApp.Features.FirstTest do
  use Cabbage.Feature, async: false

  defgiven ~r/^client (?<number>\d+) connects$/, _, _ do
    ...
  end

  defwhen ~r/^client (?<number>\d+) sends "(?<text>.*?)"$/, _, _ do
    ...
  end

  defthen ~r/^client (?<number>\d+) receives "(?<text>.*?)"$/, _, _ do
    ...
  end
  
  deffeature "file1.feature" do
    # You can use defgiven, defwhen and defthen again here, specific
    # and generic definitions would be available in the feature file.
  end

  deffeature "file2.feature" do
    # same
  end
end

In short, we don't specify the feature file. We can define keywords as usual. And then define several files in blocks (allowing for additional keywords for each). This would indeed create something quite powerful where the central definition can easily be found, but several feature files can still exist without duplicating definitions.

I'm a bit uncertain about this: the first solution has the advantage of simplicity. Think "extract all keywords from every step, then apply the features regardless". It's easy to explain. The second situation, while closer to the expected behavior of Cabbage, has the downsides of pushing generic features in a central place. The single step file might become quite huge and hard to manage, while the feature files could be spread in many files (and directories?).

Looking forward to feedback,