nicholasjhenry

defmodule TypePlayground do
  defmodule Maybe do
    @type t(term) :: {:just, term} | :nothing
  end

  defmodule Result do
    @type t(term) :: {:ok, term} | {:error, atom}
  end

  defmodule ApiAction do

nicholasjhenry

Please tell us a little bit about your company

Nestled on the border of the Plateau and Mile-end in Montreal, Canada, CivilCode Inc develops tailored business applications. Nicholas Henry (@nicholasjhenry) and Hugo Frappier (@frahugo) founded the company in early 2016 to develop applications exclusively with Elixir. Before CivilCode, Nicholas and Hugo were both freelance Ruby/Rails developers.

We organize the Montreal Elixir Meetup to help grow the local community and sponsor this forum. We feel lucky that we get to use this language every day and by contributing in these ways, we hope others have the opportunity too.

How did you discover Elixir?

Nicholas discovered Elixir watching José Valim on PeepCode's Meet Elixir published in 2013. He initially fell in love with the pattern matching constructs, the appreciation for OTP came after. Two years later, over a bowl of ramen, Nicholas discussed the language with Hugo and the idea of sta

nicholasjhenry

Keybase proof

I hereby claim:

• I am nicholasjhenry on github.
• I am nicholasjhenry (https://keybase.io/nicholasjhenry) on keybase.
• I have a public key ASDsJIpuc8EXEHnE4g-kQyKfiola8K4ZPZZmGe06Exe4hQo

To claim this, I am signing this object:

nicholasjhenry

Keybase proof

I hereby claim:

• I am nicholasjhenry on github.
• I am nicholasjhenry (https://keybase.io/nicholasjhenry) on keybase.
• I have a public key ASDsJIpuc8EXEHnE4g-kQyKfiola8K4ZPZZmGe06Exe4hQo

To claim this, I am signing this object:

nicholasjhenry

Pull Request Reviews

1. Can I understand this?
2. Does this meet the requirements?
3. Are there any potential issues?

PDF with presenter notes

---

nicholasjhenry

How to connect and debug Elixir or Phoenix App at Heroku?

Heroku has a great feature called heroku ps:exec which allows you to connect to running nodes. You can use this command to connect your elixir nodes easily. And debug your nodes like in your network.

Step 1

Let's start with Procfile To run a named app at heroku your procfile should specify the app name like:

web: MIX_ENV=prod elixir --sname coolelixirapp -S mix run --no-halt

nicholasjhenry

#!/usr/bin/env bash
set -x

term_handler() {
  echo "Stopping the server process with PID $PID"
  erl -noshell -name "term@127.0.0.1" -eval "rpc:call('app@127.0.0.1', init, stop, [])" -s init stop
  echo "Stopped"
}

trap 'term_handler' TERM INT

nicholasjhenry

Arc.Ecto.Schema.cast_attachments 
	-> Arc.Ecto.Type.cast
		-> definition.store (Arc.Actions.Store)
			-> File.new (in the `var` dir)
			-> put (Arc.Storage.S3)

nicholasjhenry

defmodule Foo do
  defmacro hello(do: func) do
    IO.puts "Hello"
    func
  end
end

defmodule Bar do
  require Foo

nicholasjhenry

defmodule MyApp.Projects.Project.Policy do
  alias MyApp.System
  import Ecto.Query, only: [from: 2]

  def scope(%{role: "admin"}, _action, query), do: query
  def scope(user, _action, query), do: projects_for_user(query, user)

  defp projects_for_user(query, user) do
    user_projects =
      from project in query,