# `Splode.Error`
[🔗](https://github.com/ash-project/splode/blob/v0.3.2/lib/splode/error.ex#L5)

Use this module to create an aggregatable error.

For example:

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

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

# `t`

```elixir
@type t() :: Exception.t()
```

# `error_class?`

```elixir
@callback error_class?() :: boolean()
```

# `from_json`

```elixir
@callback from_json(map()) :: struct()
```

# `keyword_list_options?`

```elixir
@callback keyword_list_options?() :: boolean()
```

Whether a keyword list should be treated as options for building this error.

Only consulted for the module configured as a Splode's `:unknown_error`. When it returns
`true` — the default — a list that satisfies `Keyword.keyword?/1` is destructured into
`:error`, `:vars` and (if declared) `:value`, rather than being converted like any other
term.

That is surprising for terms that happen to parse as keyword lists, such as OTP exit
reasons:

```elixir
Keyword.keyword?([{:noproc, {GenServer, :call, [:some_name, :ping, 5000]}}])
#=> true
```

Returning `false` opts out: keyword lists are then converted like any other list, so
`to_error(message: "it broke")` produces two errors rather than one, and `to_error([])`
produces an empty error class rather than an unknown error. The default will change to
`false` in the next major version.

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

  def keyword_list_options?, do: false
end
```

# `splode_error?`

```elixir
@callback splode_error?() :: boolean()
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*