Project: RSpec Expectations 3.0

Publisher: RSpec

define matcher with fluent interface

Use the chain method to define matchers with a fluent interface.

Scenarios

Given

a file named "between_spec.rb" with:

RSpec::Matchers.define :be_bigger_than do |first|
  match do |actual|
    (actual > first) && (actual < @second)
  end

  chain :but_smaller_than do |second|
    @second = second
  end
end

RSpec.describe 5 do
  it { is_expected.to be_bigger_than(4).but_smaller_than(6) }
end

When

I run rspec between_spec.rb --format documentation

Then

the output should contain "1 example, 0 failures"

And

the output should contain "should be bigger than 4"

Last published about 6 years ago by myronmarston.

define matcher with fluent interface

RSpec Expectations settings