how to invoke bundler commands from within a Serverspec/RSpec test - ruby

Question

I have a project to create a template ruby project.
I am using serverspec and want to verify the behaviour of the template.
However, using command(`rake -T`) fails. If I execute the command manually, it works as expected.
Debugging, when the test is running in Serverspec, it finds the wrong Gemfile - it is using the Gemfile from my project (.), not the generated directory (target/sample_project).
How can I invoke rake or bundler commands withing a Serverspec/Rspec test?
sample code:
require "spec_helper"
require 'serverspec'
require 'fileutils'
set :backend, :exec
set :login_shell, true
describe "Generated Template" do
output_dir='target'
project_dir="#{output_dir}/sample_project"
# Hooks omitted to create the sample_project
# and change working directory to `project_dir`
describe command('rake -T') do
its(:stdout) { should include "rake serverspec:localhost" }
its(:stdout) { should include "rake serverspec:my_app" }
end
end

Answer 1

Bundler has provision for running external shell commands documented here: http://bundler.io/v1.3/man/bundle-exec.1.html
Running bundler/rake tasks is possible using rspec using Bundler.with_clean_env, instead of Serverspec.
require 'bundler'
require 'rspec'
RSpec.describe "Generated Template" do
output_dir='target'
project_dir="#{output_dir}/sample_project"
around(:example) do |example|
#Change context, so we are in the generated project directory
orig_dir=Dir.pwd
Dir.chdir(project_dir)
example.run
Dir.chdir(orig_dir)
end
around(:example) do |example|
Bundler.with_clean_env do
example.run
end
end
it "should include localhost" do
expect(`rake -T 2>&1`).to include "rake serverspec:localhost"
end
end