get_matcher

get_matcher.rb

# coding: utf-8

require 'spec_helper'

RSpec::Matchers.define :get do |first|
  match do |actual|
    actual.public_send(@second, *@args) == first
  end

  chain :by_call do |second, *args|
    @second = second
    @args = args
  end
end

RSpec.describe 5 do
  it { is_expected.to get(6).by_call(:succ) }
  it { is_expected.to get("5").by_call(:to_s) }
  it { is_expected.to get(7).by_call(:+, 2) }
end

describe "" do
  subject { 5 }
  it "" do
    expect(subject.succ).to be 6
    is_expected.to get(6).by_call(:succ)
    is_expected.to get(7).by_call(:+, 2)
  end

  it "" do
    expect(subject.to_s).to eq "5"
  end
end