Testing Rake Tasks in Rails

I recently wrote a rake task to update some values we’ve got stored in the database. The rake task itself isn’t important in this post, but testing it is.

We’ve got many untested rake tasks in the database, so when our senior dev suggested adding a test, I had to build ours from scratch.

I did a bit more whack-a-moling with error messages than I’d hoped, so here’s a template of that test, along with some details that might save you some time, next time you are writing tests for your rake tasks.

We’re in a not-new version of Rails, and using Minitest. I’ve anonymized it. Hope it’s useful!

# test/tasks/rake_task_file_test.rb

require 'test_helper'
require 'rake'

class RakeTaskFileTaskTest < ActiveSupport::TestCase

describe 'namespace:task_name' do

def setup
@tt = Fabricate(:object_with_attributes_i_need_to_change)
ApplicationName::Application.load_tasks if Rake::Task.tasks.empty?

it "should change 'thing I don't want'" do
values = @tt.attribute_i_changed
refute_includes values, "thing I don't want"
assert_includes values, "thing I do want"


Notes on the above:

Useful resources

This article was originally posted on my own site.



Software, rock climbing, books. I love to learn. https://josh.works

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