(ArgumentError) argument error - when trying to pass a list of values to a changeset

What do you intend your changeset_all function to do? I don’t quite get your intent here.

I want to pass a list of countries to changeset not only one country.
The changeset function should validate, if all passes value is valid or not.

Yeah, well I figured that you may want to do that but:

1. You write a function in code of your app that is to be used only in tests. This is not great to pollute your app like that. Shame on you, really

2. You are destroying the readability of your test cases. You have just few values that can be valid, just add X examples of tests or test those one by one in the same test case.

@hubertlepicki So I want to test a list of countries and have to idea how to do it?
What is your suggestion?

Here is the whole code:

defmodule Pubcus.Country do

	use Pubcus.Web, :model

  schema "countries" do

    field :code, :string
    field :en, :string
    field :de, :string
    field :it, :string
    field :fr, :string

    timestamps

  end

  def changeset_all(model, list) when is_list(list) do

		list
		|> Enum.map(fn param -> changeset(model, param) end)

  end


  def changeset(model, params \\ %{}) do

		model
    |> cast(params, [:code, :en, :de, :it, :fr])
    |> validate_required([:code, :en])
    |> validate_length(:code, max: 2)
    |> unique_constraint(:code)

  end


end

and the tests

defmodule Pubcus.CountryModelTest do

  use Pubcus.ModelCase

  alias Pubcus.Country

  @valid_attrs %{ code: "CH", en: "Switzerland", de: "Schweiz", it: "Svizzera", fr: "Suisse" }
  @invalid_attrs %{ code: "CHH" }

  @valid_attrs_list [ %{code: "CH", en: "Switzerland", de: "Schweiz", it: "Svizzera", fr: "Suisse"},
                      %{code: "IT", en: "Italy", de: "Italien"},
                      %{code: "FR", en: "Franche", de: "Frankreich"} ]

  test "a valid dataset" do

    changeset = Country.changeset(%Country{}, @valid_attrs)
    assert changeset.valid?

  end

  test "a invalid country code" do

    errors = errors_on(%Country{}, @invalid_attrs)
    assert {:code, "should be at most 2 character(s)"} in errors
    assert {:en, "can't be blank"} in errors

  end

  test "a valid list of countries" do

    changeset = Country.changeset_all(%Country{}, @valid_attrs_list)
    assert changeset.valid?

  end


end

Thanks

Why it is wrong to test a list of countries?

It looks like you’re trying to call valid? on a list of changesets. I believe you need to do something like this:

changesets = Country.changeset_all(%Country{}, @valid_attrs_list)
Enum.each(changesets, &(assert(&1.valid?)))

Or this:

Enum.each(@valid_attrs_list, fn(valid_attrs) ->
  changeset = Country.changeset(%Country{}, valid_attrs)
  assert(changeset.valid?)
end)

thanks so much.