"expect(widget_factory).to have_received(:create).with({name: 'sprocket'})" Even better: expect("my_service.rb", "line X").to be("widget_factory.create") Or

"expect(widget_factory).to have_received(:create).with({name: 'sprocket'})" Even better: expect("my_service.rb", "line X").to be("widget_factory.create") Or yet better, simply: ; # realize that testing the exact implementation is bullshit