Rspec::Shell::Expectations

Run your shell script in a mocked environment to test its behaviour using RSpec.

Features

Setup a fake shell environment that has preference in exucing commands (highest path value)
Stub shell commands in this environment
Control multiple outputs (through STDOUT, STDERR or files)
Control exit status codes
Set different configurations based on command line arguments
Verify if command is called
Verify arguments command is called with
Verify STDIN

Installation

Add this line to your application's Gemfile:

gem 'rspec-shell-expectations'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec-shell-expectations

You can setup rspec-shell-expectations globally for your spec suite:

in spec_helper.rb:

  require 'rspec/shell/expectations'

  RSpec.configure do |c|
    c.include Rspec::Shell::Expectations
  end

Usage

see specs in spec/ folder:

Running script through stubbed env:

  require 'rspec/shell/expectations'

  describe 'my shell script' do
    include Rspec::Shell::Expectations

    let(:stubbed_env) { create_stubbed_env }

    it 'runs the script' do
      stdout, stderr, status = stubbed_env.execute(
        'my-shell-script.sh',
        { 'SOME_OPTIONAL' => 'env vars' }
      )
      expect(status.exitstatus).to eq 0
    end
  end

Stubbing commands:

  let(:stubbed_env) { create_stubbed_env }
  let!(:bundle) { stubbed_env.stub_command('bundle') }
  let(:rake) { bundle.with_args('exec', 'rake') }

  it 'is stubbed' do
    stubbed_env.execute 'my-script.sh'
    expect(rake.with_args('test')).to be_called
    expect(bundle.with_args('install)).to be_called
  end

Changing exitstatus:

  let(:stubbed_env) { create_stubbed_env }
  before do
    stubbed_env.stub_command('rake').returns_exitstatus(5)
    stubbed_env.stub_command('rake').with_args('spec').returns_exitstatus(3)
  end

Stubbing output:

  let(:stubbed_env) { create_stubbed_env }
  let(:rake_stub) { stubbed_env.stub_command 'rake' }
  before do
    rake_stub.outputs('informative message', to: :stdout)
      .outputs('error message', to: :stderr)
      .outputs('log contents', to: 'logfile.log')
      .outputs('converted result', to: ['prefix-', :arg2, '.txt'])
    # last one creates 'prefix-foo.txt' when called as 'rake convert foo'
  end

Verifying called:

  let(:stubbed_env) { create_stubbed_env }
  let(:rake_stub) { stubbed_env.stub_command 'rake' }
  it 'verifies called' do
    stubbed_env.execute_script 'script.sh'

    expect(rake_stub).to be_called
    expect(rake_stub.with_args('spec')).to be_called
    expect(rake_stub.with_args('features')).not_to be_called
  end

Verifying stdin:

  let(:stubbed_env) { create_stubbed_env }
  let(:cat_stub) { stubbed_env.stub_command 'cat' }
  let(:mail_stub) { stubbed_env.stub_command 'mail' }
  it 'verifies stdin' do
    stubbed_env.execute_script 'script.sh'
    expect(cat_stub.stdin).to eql 'hello'
    expect(mail_stub.with_args('-s', 'hello').stdin).to eql 'world'
  end

More examples

see the features and spec folder

Supported ruby versions

Ruby 2+, no JRuby, due to issues with Open3.capture3

Contributing

Fork it ( https://github.com/matthijsgroen/rspec-shell-expectations/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request

rspec-shell-expectations

Development