Self-contained, one-file RSpec

self_contained_rspec.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile do
  source "https://rubygems.org"
  gem "rspec"
end

require "rspec/autorun"

RSpec.describe "Foo" do
  it "does something" do
    expect(false).to eq(false)
  end
end