Question

I can’t figure out what is ‘be’ when using rpec.

target.should be 5

I know how to use it, but how is it implemented? Is it something like an operator i.e.

target.should.send(:be, 5)

How can I implement something similar?

Answer 1

be is a method which returns an RSpec Matcher, as mentioned by d11wtq in a comment above

You can implement any other method which returns a matcher, but there are other, simpler ways to write a matcher.

RSpec::Matchers.define :be_a_multiple_of do |expected|
  match do |actual|
    actual % expected == 0
  end
end

describe 9 do
  it "should be a multiple of 3" do
    9.should be_a_multiple_of(3)
  end
end