Using default options when testin thor tasks - thor

Question

I would like to test thor tasks with rspec, but when calling them from rspec I have two requirements:
I would like to have Thor Class instance available
I would like to call tasks with default options (as it will be called from command line)
I am not able to achieve both of these at the same time, consider following code:
require 'thor'
require 'thor/runner'
class App < Thor
method_option :foo , :default => "foovalue"
desc "xlist", "list"
def xlist(search="")
p options
end
end
app = App.new
app.xlist
app.invoke(:xlist)
App.start ARGV
Output is:
> ruby contrib/thor_test.rb xlist
{}
{}
{"foo"=>"foovalue"}
In the first two examples, I can call task through instance but default options are not passed to method (which makes spec unrealistic)
In the third example, I get default options but I can't set expectations on class instance, neither I can stub any methods which makes it hard to test. That is happening because class instance is created on the fly.

Answer 1

If you ask how you can test thor cli utility, I read through the thor specs as suggested in this SO answer. Examples here were particularly helpful and could be used directly.
Spec:
require 'my_thor'
describe MyThor do
it "should work" do
args = ["command", "--force"]
options = MyThor.start(args)
expect(options).to eq({ "force" => true })
end
end
Code:
class MyThor < Thor
desc "command", "do something"
method_option :force, :type => :boolean, :aliases => '-f'
def command
return options
end
end

Answer 2

I was able to do extract default options for a Thor command by:
Getting Thor's internal representation of the options list for that command
Building a Thor::Options object from that command list
Using that Thor::Options object to parse an empty array of options, which returns a hash of only the defaults.
The code is in get_default_options_for_command below. Honestly, I'm hoping there's a better way to do it, but I couldn't find one.
Once you've got a Thor object, you can replace its options to include those defaults plus whatever other options you want to add, then run it with #xlist.
I wrote this all up using your example above:
require 'thor'
def get_default_options_for_command(klass,command_name)
option_precursors = klass.all_commands[command_name].options
parser = Thor::Options.new(option_precursors)
parser.parse([])
end
class App < Thor
desc "xlist", "list"
method_option :foo , :default => "foovalue"
method_option :bar
def xlist(search="")
puts "search: #{search}"
puts "options: #{options}"
end
end
app = App.new
xlist_default_opts = get_default_options_for_command(App,'xlist')
new_opts = { :bar => 3 }
app.options = xlist_default_opts.merge(new_opts)
app.xlist('search-term')
The output is:
$ ./test.rb
search: search-term
options: {"foo"=>"foovalue", "bar"=>3}