Ruby/Rspec: Possible to compare the content of two objects?

Question

I've created 2 different objects in ruby with exactly the same attributes and values.

I'd like to compare now that the content of both objects is the same but the following comparisons:

actual.should == expected
actual.should eq(expected)
actual.should (be expected)

fail with:

  Diff:
  @@ -1,4 +1,4 @@
  -#<Station:0x2807628
  +#<Station:0x2807610

Is there any way in rspec/ruby to easily achieve this?

Cheers!!

Answer 1

An idiomatic way to do this is to override the #== operator:

class Station
  def ==(o)
    primary_key == o.primary_key
  end

  def hash
    primary_key.hash
  end
end

When you do this, you generally want to override the #hash method as well. It is less common to override #eql? or #equal?.

EDIT: Another thing you can do in this specific case, which does not involve overriding #==, is to make a custom RSpec matcher.

Answer 2

Use the have_attributes matcher to specify that an object's attributes match the expected attributes:

  Person = Struct.new(:name, :age)
  person = Person.new("Jim", 32)

  expect(person).to have_attributes(:name => "Jim", :age => 32)
  expect(person).to have_attributes(:name => a_string_starting_with("J"), :age => (a_value > 30) )

Relishapp RSpec Docs

Answer 3

A bit late, but you could serialize it, per example:

require 'json'

expect(actual.to_json).to eq(expected.to_json) #new rspec syntax
actual.to_json.should eq(expected.to_json) #old rspec syntax