ElixirConf 2022 Productivity Takeaways

I am a huge fan of improving development workflows. The less I have to think about incidental things, the more I can concentrate on the problems that matter. One talk from ElixirConf 2022 helped improve my development workflow.

Jason Axelson doled out some essential tips to speed up Elixir development. A few quick wins for me included setting the ELIXIR_EDITOR and ERL_AFLAGS environment variables. Setting ELIXIR_EDITOR to your favorite editor allows you to quickly open module and function definitions for a given library or Elixir itself in your favorite editor from iex.

Visual Studio Code

export ELIXIR_EDITOR="code --goto __FILE__:__LINE__"

Emacs

export ELIXIR_EDITOR="emacs +__LINE__ __FILE__"

 

Once you have your favorite editor setup, you can start opening and exploring the code. This is a great way to learn and find out more when you are stuck on a problem outside of your application code.

iex(1)> open Phoenix.LiveView

When the ERL_AFLAGS environment variable is set you can search previously executed commands in iex across sessions. Without the ERL_AFLAGS set, you can only search the current iex session. The same keyboard shortcuts for your shell (bash is Ctrl+r). Instead of re-typing commands over and over, we can search and make a selection and re-run a command.

Shell

export ERL_AFLAGS="-kernel shell_history enabled"

 

Open iex and follow along.

iex(1)> IO.puts("Hello Binary Noggin")

Hello Binary Noggin

:ok

iex(2)> IO.inspect("Binary Noggin says hello")

"Binary Noggin says hello"

"Binary Noggin says hello"

iex(3)> # Ctrl+r and type puts. If you  This will look like the below replacing iex(3)>. Now hit ~enter~ and it'll choose the ~IO.puts~ command we executed. Now we can make changes or re-execute by hitting the ~enter~ key.

(search)`puts': IO.puts("Hello World")

 

I also learned about the library ExSync for Elixir code recompiling and reloading. I have added this to my workflow so I can get non-Phoenix applications to be rebuilt on code changes. Try out ExSync by adding the below to your mix.exs dependencies. It is really useful when you are developing a library and want to play around with it in iex and have it reload between changes.

{:exsync, "~> 0.2", only: :dev}

 

These tips have sped up my development processes, but Jason has many more. You can find those on Jason's slides.