Testing

Ductwork provides custom RSpec matchers and some helpers to simplify pipeline testing.

RSpec matchers

have_triggered_pipeline

Use this matcher to verify that a single pipeline was triggered. It requires a block and takes one pipeline class as its argument.

expect do
  MyService.call
end.to have_triggered_pipeline(MyPipeline)

Specifying Execution Count

You can assert that a pipeline was triggered a specific number of times:

expect do
  MyService.call
end.to have_triggered_pipeline(MyPipeline).exactly(3).times

have_triggered_pipelines

Use this matcher to verify that multiple pipelines were triggered. It takes multiple pipeline classes as arguments.

expect do
  MyService.call
end.to have_triggered_pipelines(MyPipelineA, MyPipelineB, MyPipelineC)

Note: This matcher does not support count expectations, as specifying counts for multiple pipelines would be ambiguous.

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Creating steps

Because of Reasons, Ductwork steps are built in a non-standard way. This means you need to use the following to instantiate steps:

let(:step) { FetchUserData.build_for_execution(pipeline_id, attrs) }

The first argument is the pipeline ID to which the step belongs followed by any input arguments.

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Creating pipelines

To make creating pipeline objects easier you can use the pipeline_for helper which only takes a class name:

let(:pipeline) { pipeline_for(EnrichAllUsersDataPipeline) }

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Setting context

Likewise there is a helper to make setting global state easier:

before do
  set_pipeline_context(pipeline, user_id: 1)
end

For convenience, you can use string or symbol keys to set context state.

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Pipeline validation

It is useful to know if your pipeline and step classes are valid before pushing to production. There is a top-level Ductwork.validate! method that will ensure your step classes have the correct methods and arity and that each pipeline is calling transitions correctly. It is recommended to call this method in a test:

RSpec.describe "Ductwork" do
  specify "valid pipelines and steps" do
    Ductwork.validate!
  end
end