gistfile1.rb

describe "calculator" do
  it "should add two numbers together" do
    expect_that "2 + 3 = 5" do
      Calculator.new.add(2,3).should == 5
    end
  end
end

# if the expectation failed then the message would be 'expected 2 + 3 == 5, but got 6'
# perhaps this could be altered/extended with a way to insert the actual result with something like...

describe "calculator" do
  it "should add two numbers together" do
    expect_that "2 + 3 = 5 but we got $ACTUAL" do
      Calculator.new.add(2,3).should == 5
    end
  end
end