Example of using temporary directory at rspec

uses_temp_dir.rb

shared_context :uses_temp_dir do
  around do |example|
    Dir.mktmpdir("rspec-") do |dir|
      @temp_dir = dir
      example.run
    end
  end

  attr_reader :temp_dir
end

uses_temp_dir_spec.rb

describe "example of uses_temp_dir" do
  include_context :uses_temp_dir

  it "should create temp_dir" do
    expect(Dir.exists?(temp_dir)).to be true
  end

  it "can create file in temp_dir" do
    temp_file = "#{temp_dir}/temp.txt"

    File.open(temp_file, "w") do |f|
      f.write("foo")
    end

    expect(File.read(temp_file)).to eq "foo"
  end
end