require 'spec_helper' class TestShell include ImageOptimizer::Shell end describe ImageOptimizer::Shell do subject { TestShell.new } describe '#which' do it 'should find ruby' do expect(subject.which('ruby')).to_not be_nil end it 'should not find it' do expect(subject.which('something_that_should_not_exist_ever')).to be_nil end end describe '#run_command' do it 'run the command successfully' do expect(subject.run_command('ruby -v')).to_not be_nil end end end