Alternate implementation for https://thomasleecopeland.com/2018/02/12/increment-decrement-matcher.html

increment_and_decrement.rb

# frozen_string_literal: true

RSpec::Matchers.alias_matcher :increment, :change do |desc|
  desc.gsub("changed", "incremented").gsub("change", "increment")
end

RSpec::Matchers.alias_matcher :decrement, :change do |desc|
  desc.gsub("changed", "decremented").gsub("change", "decrement").gsub("-", "")
end

module IncrementAndDecrement
  def increment(by: 1, &block)
    super(&block).by(by)
  end

  def decrement(by: 1, &block)
    super(&block).by(-by)
  end
end

RSpec.configure do |c|
  c.include IncrementAndDecrement
end