PhoenixTest now has a very clean way to do this:

visit(conn, "/")
|> assert_has(".my-list li", "One", at: 1)
|> assert_has(".my-list li", "Two", at: 2)
|> assert_has(".my-list li", "Three", at: 3)

I just take the simple boneheaded approach:

insert(
  :list,
  items: [
    build(:item, name: "One"),
    build(:item, name: "Two"),
    build(:item, name: "Three")
  ]
)

assert lv
       |> element(".list-container")
       |> render() =~ ~r/One.*Two.*Three/s

The s regex modifier allows matching over line breaks.

So I don’t know why I never thought of this before but out of the box you can use CSS selectors along with has_element?/3 for much more fine-grained and reliable results than my current regex solution:

assert has_element?(lv, ".my-list li:nth-child(1)", "One")
assert has_element?(lv, ".my-list li:nth-child(2)", "Two")
assert has_element?(lv, ".my-list li:nth-child(3)", "Three")

cc: @travisf