Correct use of rspec matching

a_kind_of_spec.rb

  describe 'Expectations' do
    it 'fails with the wrong expectations' do
      my_hash = { 'created_at' => Time.now }
      expect(my_hash['created_at']).to be_a_kind_of(Time)

      # expect(my_hash)
      #   .to eql({ 'created_at' => a_kind_of(Time) })
      # expect(my_hash)
      #   .to eq({ 'created_at' => a_kind_of(Time) })

      array_of_hashes = [ my_hash ]
      # expect(array_of_hashes)
      #   .to eql([ { 'created_at' => a_kind_of(Time) } ])
      # expect(array_of_hashes)
      #   .to eq([ { 'created_at' => a_kind_of(Time) } ])
    end

    it 'works with the right expectations' do
      my_hash = { 'created_at' => Time.now }
      expect(my_hash['created_at']).to be_a_kind_of(Time)

      expect(my_hash)
        .to match({ 'created_at' => a_kind_of(Time) })

      array_of_hashes = [ my_hash ]
      expect(array_of_hashes)
        .to contain_exactly({ 'created_at' => a_kind_of(Time) })
      expect(array_of_hashes)
        .to match_array([ { 'created_at' => a_kind_of(Time) } ])
    end
  end