sultaniman

# Your actual dynamic worker
defmodule Awesome.Worker do
  use GenServer, restart: :transient
  alias Awesome.Hero

  # Client
  def start_link(%Hero{} = hero), do:
    GenServer.start_link(@mod, hero, name: proc_name(hero))

  defp proc_name(%Hero{name: name}), do:

sultaniman

def from_packages_list(data: str) -> Generator:
    """Parses CRAN package metadata from
    https://cran.r-project.org/src/contrib/PACKAGES
    and returns the list of dictionaries.

    Args:
        data (str): raw text from the package list

    Returns:
        (Generator): each entry from packages as dictionary

sultaniman

def process_errors(%Changeset{} = changeset) do
  %{
    message: "Changeset errors occurred",
    code: :schema_errors,
    errors: to_api_errors(changeset)
  }
end

sultaniman

# add this to your schema module

# if it's a field for the mutation object, add this middleware to the end
def middleware(middleware, _field, %{identifier: :mutation}) do
  middleware ++ [Idp.Middlewares.HandleAPIErrors]
end

# if it's any other object keep things as is
def middleware(middleware, _field, _object), do: middleware

sultaniman

defmodule Idp.Middlewares.HandleAPIErrors do
  @behaviour Absinthe.Middleware
  alias Idp.EctoHelpers

  def call(resolution, _config) do
    errors =
      resolution
      |> Map.get(:errors)
      |> Enum.flat_map(&process_errors/1)

sultaniman

def action_wrapped(fun) do
  case fun.() do
    {:ok, result} ->
      {:ok, result}

    {:error, changeset = %Changeset{}} ->
      {
        :error,
        %{
          message: "Changeset errors occurred",

sultaniman

defmodule IdpWeb.Schema.CityResolvers do
  use IdpWeb.Schema.Errors

  alias Idp.Geo.Cities
  alias Idp.EctoHelpers

  def create(_parent, city, _ctx) do
    EctoHelpers.action_wrapped(fn ->
      Cities.create_city(city)
    end)

sultaniman

defmodule IdpWeb.Schema.Errors do
  @moduledoc """
  Defines common GraphQL error responses
  """
  defmacro __using__(_) do
    quote do
      @permission_denied {
        :error,
        %{
          message: "Permission denied",

sultaniman

defmodule Idp.EctoHelpers do
  alias Ecto.Changeset

  @doc """
  Transform `%Ecto.Changeset{}` errors to a map
  containing field name as a key on which validation
  error happened and it's formatted message.

  For example:

sultaniman

{
  :error,
  %{
    message: "Changeset errors occurred",
    code: :changeset_errors,
    errors: [
      %{field: "error message"}
    ]
  }
}