hash_matching: an RSpec arguments matcher like hash_including, but which handles Regexps

custom_argument_matchers.rb

# spec/support/custom_argument_matchers.rb
module CustomArgumentMatchers
  class HashMatching
    attr_reader :expected

   def initialize(expected)
     @expected = expected
    end

    def ==(target)
      expected.each do |key, matcher|
        return false unless target.include?(key)

        if matcher.is_a?(Regexp)
          return false unless target[key].match(matcher)
          next
        end

        return false unless target[key] == matcher
      end

      true
    end

    def inspect
      "a Hash with elements matching #{expected.inspect}"
    end
  end

  def hash_matching(expected)
    HashMatching.new(expected)
  end
end

foo_spec.rb

describe 'foos' do
  it 'calls a method' do
    expect(bar).to have_received(:baz).with(hash_matching(quux: 'Hi', fnord: /hi/))
  end
end

spec_helper.rb

# spec/spec_helper.rb
RSpec.configure do |config|
  config.include CustomArgumentMatchers
end