# Splode - Aggregatable and consistent errors for Elixir

**URL:** <https://forum.elixirforum.com/t/splode-aggregatable-and-consistent-errors-for-elixir/62313>\
**Category:** Announcing\
**Tags:** library, ash\
**Created:** [March 15, 2024, 12:43am UTC](https://forum.elixirforum.com/t/splode-aggregatable-and-consistent-errors-for-elixir/62313 "2024-03-15T00:43:08Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![zachallaun](https://forum.elixirforum.com/user_avatar/forum.elixirforum.com/zachallaun/32/29208_2.png) [@zachallaun](https://forum.elixirforum.com/u/zachallaun)\
**Post date:** [March 15, 2024, 1:57pm UTC](https://forum.elixirforum.com/t/splode-aggregatable-and-consistent-errors-for-elixir/62313/2 "2024-03-15T13:57:59Z")

</div>

Neat! I can think of a few places where this would clean up some of my own code.

A few ergonomics improvements that come to mind:

1. To ease the transition from existing custom exceptions to Splode and to decrease the API footprint, the existing `message` callback could be wrapped instead of using a `splode_message` callback.

2. Implement a default `splode_message` (or `message` if the first suggestion is taken) that, for instance, just inspects the `:fields` present in the error.

These last two I’m less sure of, but would pretty significantly reduce boilerplate:

1. Allow module namespaces to be used as implicit error classes when unspecified. For instance:

2. Define error classes explicitly with `use Splode.ErrorClass` as opposed to implicitly by including a `:errors` field. This could inject the `splode_message` implementation, which it looks like will almost always (or just always?) be the same.

* * *

Taken all together, before:

```elixir
defmodule MyApp.Errors do
  use Splode, error_classes: [
    invalid: MyApp.Errors.Invalid,
    unknown: MyApp.Errors.Unknown
  ],
  unknown_error: MyApp.Errors.Unknown.Unknown
end

defmodule MyApp.Errors.Invalid do
  use Splode.Error, fields: [:errors], class: :invalid

  def splode_message(%{errors: errors}) do
    Splode.ErrorClass.error_messages(errors)
  end
end

defmodule MyApp.Errors.Unknown do
  use Splode.Error, fields: [:errors], class: :unknown

  def splode_message(%{errors: errors}) do
    Splode.ErrorClass.error_messages(errors)
  end
end

defmodule MyApp.Errors.Unknown.Unknown do
  use Splode.Error, fields: [:error], class: :unknown

  def splode_message(%{error: error}) do
    if is_binary(error) do
      to_string(error)
    else
      inspect(error)
    end
  end
end

defmodule MyApp.Errors.InvalidArgument do
  use Splode.Error, fields: [:name, :message], class: :invalid

  def splode_message(%{name: name, message: message}) do
    "Invalid argument #{name}: #{message}"
  end
end

```

And after:

```elixir
defmodule MyApp.Errors do
  use Splode,
    error_classes: [MyApp.Errors.Invalid, MyApp.Errors.Unknown],
    unknown_error: MyApp.Errors.Unknown.Unknown
end

defmodule MyApp.Errors.Invalid do
  use Splode.ErrorClass
end

defmodule MyApp.Errors.Unknown do
  use Splode.ErrorClass
end

defmodule MyApp.Errors.Unknown.Unknown do
  use Splode.Error, fields: [:error]
end

defmodule MyApp.Errors.InvalidArgument do
  use Splode.Error, fields: [:name, :message]

  def splode_message(%{name: name, message: message}) do
    "Invalid argument #{name}: #{message}"
  end
end

```

---

_[View the full topic](https://forum.elixirforum.com/t/splode-aggregatable-and-consistent-errors-for-elixir/62313)._