Testing on Codrut Constantin Gusoi

RSpec Instance Double

Tue, 11 Jul 2023 19:49:39 +0000

Here is how you can make an assertion on a nested call to another class:

let(:double) { instance_double('something') }

before do
  allow(SomeClass).to receive(:some_method).and_return(double)
  allow(double).to receive(:another).and_return(true)
end

it 'does something useful' do
  subject.call

  expect(SomeClass).to have_received(:some_method).with(args)
  expect(double).to have_received(:another).with(other_args)
end

How to Use: Minitest Mocks

Fri, 15 Apr 2022 20:10:16 +0000

Prerequisite Link to heading

Ruby Minitest and Simplecov starter

Usage Link to heading

# Create a mock
mock = Minitest::Mock.new

# Add expectations.
#
# Arguments:
#   1. Method name
#   2. What to return when called
#   3. Expected inputs
mock.expect(:read!, { result: 1 }, ['first'])

# Now you pass the mock around and execute your tests.
subject = described_class.new(something: mock)
subject.add(:a)

# Verify the expectations were met.
mock.verify

Limitations Link to heading

You can’t mock #respond_to? for some reason, at least I could not when I tried it. But it might have been a bug and it works now? Can somebody verify?

Ruby Minitest and Simplecov starter

Wed, 30 Sep 2020 18:38:47 +0000

Add these gems to your Gemfile:

# frozen_string_literal: true

group :development, :test do
  gem 'minitest'
  gem 'rake'
  gem 'simplecov'
end

Run bundle install to install them.
Create a test/test_helper.rb file containing:

# frozen_string_literal: true

require 'simplecov'
SimpleCov.start do
  enable_coverage :branch
end

$LOAD_PATH.unshift File.expand_path('../lib', __dir__)

require 'minitest/autorun'

Add the following lines to your Rakefile:

# frozen_string_literal: true

require 'rake/testtask'

Rake::TestTask.new(:test) do |t|
  t.libs << 'test'
  t.libs << 'lib'
  t.test_files = FileList['test/**/*_test.rb']
end

Create a sample test at test/unit/trial_test.rb to try it out:

# frozen_string_literal: true

require 'test_helper'

describe 'trial' do
  it 'is worthy' do
    assert(true)
  end
end

Run the tests with bundle exec rake test