• Add assert_part and assert_no_part to ::ActionMailer::TestCase

  test "assert MyMailer.welcome HTML and text parts" do
    mail = MyMailer.welcome("Hello, world")
  
    assert_part :text, mail do |text|
      assert_includes text, "Hello, world"
    end
    assert_part :html, mail do |html|
      assert_dom html.root, "p", "Hello, world"
    end
  end

  Sean Doyle

Please check [8-1-stable]) for previous changes.