require 'rspec'

Person = Struct.new(:name, :age)

RSpec.describe do
  subject { Person.new("Bob", 32) }

  it { is_expected.to have_attributes(name: "Bob", age: 33) }

  # ^ This failure prints the attributes diff as follows:

  # 1) is expected to have attributes {:age => 33, :name => "Bob"}
  #    Failure/Error: it { is_expected.to have_attributes(name: "Bob", age: 33) }
  #
  #      expected #<struct Person name="Bob", age=32> to have attributes {:age => 33, :name => "Bob"} but had attributes {:age => 32, :name => "Bob"}
  #      Diff:
  #      @@ -1 +1 @@
  #      -:age => 33,
  #      +:age => 32,
  #
  #    # ./test_have_attributes_and.rb:9:in `block (2 levels) in <top (required)>'

  it { is_expected.to be_a(Person).and have_attributes(name: "Bob", age: 33) }

  # ^ This failure prints the whole object rather than the attribute diff

  # 2) is expected to be a kind of Person and have attributes {:age => 33, :name => "Bob"}
  #    Failure/Error: it { is_expected.to be_a(Person).and have_attributes(name: "Bob", age: 33) }
  #
  #      expected #<struct Person name="Bob", age=32> to have attributes {:age => 33, :name => "Bob"} but had attributes {:age => 32, :name => "Bob"}
  #      Diff for (have attributes {:age => 33, :name => "Bob"}):
  #      @@ -1,3 +1,2 @@
  #      -:age => 33,
  #      -:name => "Bob",
  #      +"#<struct Person name=\"Bob\", age=32>"
  #
  #    # ./test_have_attributes_and.rb:12:in `block (2 levels) in <top (required)>'
end