Make elixir app recompile and reload on source code change

Question

How to automatically recompile and reload my iex + mix application every time I modify the source code?

If there's no way for iex + mix combination to do that, what's the easiest alternative? I've checked phoenix's way to do reload, and it doesn't seems easy to implement for my small test project.

I also know about José's .iex.exs :

defmodule R do
  def reload! do
    Mix.Task.reenable "compile.elixir"
    Application.stop(Mix.Project.config[:app])
    Mix.Task.run "compile.elixir"
    Application.start(Mix.Project.config[:app], :permanent)
  end
end

And I'm not extremely happy since it's not reloading automatically on code change, I still need to type R.reload! on iex.

And.. please help me create "iex" tag on stackoverflow, my reputation is not sufficient :)

Trixie

I think we had some discussions on elixir-lang-talk mailing list about this. I think even some open source projects came out of it... or was it for mix test.watch? – Birkner

ahh... yes there a few projects on github, I'll test and comeback whether they are working or not. – Trixie

Answer 1

Currently iex has an internal function to do this:

invoke IEx.Helpers.recompile inside iex console.

Trixie

You don't need to type the fully qualified command IEx.Helpers.recompile, it's enough to just run recompile – Amain

you can just do iex> r My.Module – Nofretete

Answer 2

I think this is what you are looking for: https://github.com/AgilionApps/remix

Circumvallate

Answer 3

Closest thing i know of is in Alchemist for emacs by @tonini. In Alchemist, there's an option to enable

(setq alchemist-hooks-test-on-save t)

which makes it compile and runs tests when you save.

https://github.com/tonini/alchemist.el#testing

Lues

Answer 4

For Erlang, I was using "relx -d" together with https://github.com/rustyio/sync The "-d" means that source files are linked using symlinks.

The same works nicely in Elixir. In mix.exs I added :sync in the following two places

  defp deps do
        [{:sync, git: "https://github.com/rustyio/sync.git", tag: "master"}, ....


  def application do
    [applications: [:logger, :sync],

Then, the following command compiles it into a release (before it works, you will have to install hex and exrm).

mix release -dev

Now, when you change a .ex file, and save, it will be recompiled and loaded directly.

19:33:46.474 [info]  ... /apps/testapp1/lib/kv/bucket.ex:0: Recompiled.

You only want sync in your development environment!

Acton

I do not think this could be working right due to: github.com/rustyio/sync/issues/56 – Allerus

@Michael Terry yes, same problem here. – Kurtzman

This doesn't work for elixir consistently. Infinite loop mania. – Lotta

Answer 5

https://github.com/falood/exsync/ is another library that will automatically recompile your code when the source code changes.

Cozza