• Yorick Peterse's avatar
    Basic setup for an RSpec based benchmark suite · 19893a1c
    Yorick Peterse authored
    This benchmark suite uses benchmark-ips
    (https://github.com/evanphx/benchmark-ips) behind the scenes. Specs can
    be turned into benchmark specs by setting "benchmark" to "true" in the
    top-level describe block like so:
    
        describe SomeClass, benchmark: true do
    
        end
    
    Writing benchmarks can be done using custom RSpec matchers, for example:
    
        describe MaruTheCat, benchmark: true do
          describe '#jump_in_box' do
            it 'should run 1000 iterations per second' do
              maru = described_class.new
    
              expect { maru.jump_in_box }.to iterate_per_second(1000)
            end
          end
        end
    
    By default the "iterate_per_second" expectation requires a standard
    deviation under 30% (this is just an arbitrary default for now). You can
    change this by chaining "with_maximum_stddev" on the expectation:
    
        expect { maru.jump_in_box }.to iterate_per_second(1000)
          .with_maximum_stddev(10)
    
    This will change the expectation to require a maximum deviation of 10%.
    
    Alternatively you can use the it block style to write specs:
    
        describe MaruTheCat, benchmark: true do
          describe '#jump_in_box' do
            subject { -> { described_class.new } }
    
            it { is_expected.to iterate_per_second(1000) }
          end
        end
    
    Because "iterate_per_second" operates on a block, opposed to a static
    value, the "subject" method must return a Proc. This looks a bit goofy
    but I have been unable to find a nice way around this.
    19893a1c
spec_helper.rb 1.22 KB