hashes_equal

HashesEqual

Provides a MiniTest style assertion assert_hashes_equal allowing you to compare two hashes (Hash), with an output that is a bit friendlier on the eye, than what you would get with an assert_equal. This is typically useful if you dislike spending time looking for a small difference between two large hashes.

require 'hashes_equal/hash_compare_helper'

class HashCompareHelperTest < Minitest::Test
  include HashesEqual::HashCompareHelper

  def test_disagreement_in_the_deep
    expected_hash = {
      a: {
        b: 1,
        c: 2
      }
    }
    actual_hash = {
      a: {
        b: 1,
        c: 3
      }
    }
    assert_hashes_equal(
      expected_hash,
      actual_hash
    )
  end
end

  test_disagreement_in_the_deep                                 FAIL (0.00s)
        
        values for a.c differ
        	expected: 2
        	actual: 3.
        Expected: {:a=>{:b=>1, :c=>2}}
          Actual: {:a=>{:b=>1, :c=>3}}
        hashes_equal/lib/hashes_equal/hash_compare_helper.rb:13:in `assert_hashes_equal'

Underneath, Hashdiff is used to perform the comparison.

You may also use assert_enumerable_equal from EnumerableCompareHelper:

  def test_disagreement_in_arrays
    expected_beatles = [
      { firstname: 'John', lastname: 'Lennon' },
      { firstname: 'Paul', lastname: 'McCartney' },
      { firstname: 'Ringo', lastname: 'Starr' },
      { firstname: 'George', lastname: 'Harrison' }
    ]
    actual_beatles = [
      { firstname: 'John', lastname: 'Lennon' },
      { firstname: 'Paul', lastname: 'McCartney' },
      { firstname: 'Ringo', lastname: nil },
      { firstname: 'George', lastname: 'Harrison' }
    ]

    assert_enumerable_equal(
      expected_beatles,
      actual_beatles
    )
  end

  test_disagreement_in_arrays                                     FAIL (0.00s)
        
        actual value for [2] is missing, expected was
        	{:firstname=>"Ringo", :lastname=>"Starr"}
        spurious value {:firstname=>"Ringo", :lastname=>nil} for [2] was not expected.
        --- expected
        +++ actual
        @@ -1 +1 @@
        -[{:firstname=>"John", :lastname=>"Lennon"}, {:firstname=>"Paul", :lastname=>"McCartney"}, {:firstname=>"Ringo", :lastname=>"Starr"}, {:firstname=>"George", :lastname=>"Harrison"}]
        +[{:firstname=>"John", :lastname=>"Lennon"}, {:firstname=>"Paul", :lastname=>"McCartney"}, {:firstname=>"Ringo", :lastname=>nil}, {:firstname=>"George", :lastname=>"Harrison"}]
        hashes_equal/lib/hashes_equal/enumerable_compare_helper.rb:13:in `assert_enumerable_equal'

The quality of the results you will get, will depend on Hashdiff ability to process the Enumerable you are comparing.

Installation

Add this line to your application's Gemfile:

gem 'hashes_equal'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install hashes_equal

Usage

require 'hashes_equal/hash_compare_helper'

class HashCompareHelperTest < Minitest::Test
  include HashesEqual::HashCompareHelper

  def test_disagreement_in_the_deep
    expected_hash = {
      a: {
        b: 1,
        c: 2
      }
    }
    actual_hash = {
      a: {
        b: 1,
        c: 3
      }
    }
    assert_hashes_equal(
      expected_hash,
      actual_hash
    )
  end
end

  test_disagreement_in_the_deep                                 FAIL (0.00s)
        
        values for a.c differ
        	expected: 2
        	actual: 3.
        Expected: {:a=>{:b=>1, :c=>2}}
          Actual: {:a=>{:b=>1, :c=>3}}
        hashes_equal/lib/hashes_equal/hash_compare_helper.rb:13:in `assert_hashes_equal'

You may also use assert_enumerable_equal from EnumerableCompareHelper:

  def test_disagreement_in_arrays
    expected_beatles = [
      { firstname: 'John', lastname: 'Lennon' },
      { firstname: 'Paul', lastname: 'McCartney' },
      { firstname: 'Ringo', lastname: 'Starr' },
      { firstname: 'George', lastname: 'Harrison' }
    ]
    actual_beatles = [
      { firstname: 'John', lastname: 'Lennon' },
      { firstname: 'Paul', lastname: 'McCartney' },
      { firstname: 'Ringo', lastname: nil },
      { firstname: 'George', lastname: 'Harrison' }
    ]

    assert_enumerable_equal(
      expected_beatles,
      actual_beatles
    )
  end

  test_disagreement_in_arrays                                     FAIL (0.00s)
        
        actual value for [2] is missing, expected was
        	{:firstname=>"Ringo", :lastname=>"Starr"}
        spurious value {:firstname=>"Ringo", :lastname=>nil} for [2] was not expected.
        --- expected
        +++ actual
        @@ -1 +1 @@
        -[{:firstname=>"John", :lastname=>"Lennon"}, {:firstname=>"Paul", :lastname=>"McCartney"}, {:firstname=>"Ringo", :lastname=>"Starr"}, {:firstname=>"George", :lastname=>"Harrison"}]
        +[{:firstname=>"John", :lastname=>"Lennon"}, {:firstname=>"Paul", :lastname=>"McCartney"}, {:firstname=>"Ringo", :lastname=>nil}, {:firstname=>"George", :lastname=>"Harrison"}]

Note that assert_hashes_equal will only work with Hashes while assert_enumerable_equal will accept any two Enumerable (but might or might not be able to compare them depending on their actual interface).

Development

Run bundle exec rake test to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Facilecomm/hashes_equal. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

Credit

Original idea and initial version of the code by Robert Dober.

Actual hashes comparison is performed using Hashdiff.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the HashesEqual project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.