elixir-todo-list/test/todo/list_test.exs

defmodule Todo.TestList do
  use ExUnit.Case
  alias Todo.List

  test "simple usage" do
    list = List.new()
    assert [] = List.entries(list, ~D[2024-08-04])

    list = List.add(list, %{date: ~D[2024-08-04], title: "Write some Elixir"})

    assert [%{date: ~D[2024-08-04], title: "Write some Elixir"}] =
             List.entries(list, ~D[2024-08-04])
  end

  test "id starts at 1 and increases by 1" do
    list = List.new()
    list = List.add(list, %{date: ~D[2024-08-04], title: "Write some Elixir"})

    assert [%{date: ~D[2024-08-04], title: "Write some Elixir", id: 1}] =
             List.entries(list, ~D[2024-08-04])

    list = List.add(list, %{date: ~D[2024-08-04], title: "Write more Elixir"})

    assert [
             %{date: ~D[2024-08-04], title: "Write some Elixir", id: 1},
             %{date: ~D[2024-08-04], title: "Write more Elixir", id: 2}
           ] =
             List.entries(list, ~D[2024-08-04])
  end

  test "new/1 has expected elements" do
    list =
      List.new([
        %{date: ~D[2024-08-04], title: "Write some Elixir"},
        %{date: ~D[2024-08-04], title: "Write more Elixir"}
      ])

    assert [
             %{date: ~D[2024-08-04], title: "Write some Elixir"},
             %{date: ~D[2024-08-04], title: "Write more Elixir"}
           ] =
             List.entries(list, ~D[2024-08-04])
  end

  test "entries returns correct dates" do
    list =
      List.new([
        %{date: ~D[2024-08-03], title: "Prepare writing Elixir"},
        %{date: ~D[2024-08-04], title: "Write some Elixir"},
        %{date: ~D[2024-08-05], title: "Pause writing Elixir"},
        %{date: ~D[2024-08-04], title: "Write more Elixir"}
      ])

    assert [%{date: ~D[2024-08-04]}, %{date: ~D[2024-08-04]}] = List.entries(list, ~D[2024-08-04])
  end

  test "update/3 updates selected entry" do
    list =
      List.new([
        %{date: ~D[2024-08-04], title: "Write some Elixir"},
        %{date: ~D[2024-08-04], title: "Write more Elixir"}
      ])

    updated =
      List.update(list, 1, fn %{title: title} = entry ->
        %{entry | title: String.upcase(title)}
      end)

    assert [
             %{date: ~D[2024-08-04], title: "WRITE SOME ELIXIR"},
             %{date: ~D[2024-08-04], title: "Write more Elixir"}
           ] =
             List.entries(updated, ~D[2024-08-04])
  end

  test "delete/2" do
    list =
      List.new([
        %{date: ~D[2024-08-04], title: "Write some Elixir"},
        %{date: ~D[2024-08-04], title: "Write more Elixir"}
      ])

    new_list = List.delete(list, 2)

    assert [
             %{date: ~D[2024-08-04], title: "Write some Elixir"}
           ] = List.entries(new_list, ~D[2024-08-04])
  end
end