Quick Start

We will use rebar3 to make our lifes easier, please install it in a place in $PATH.

First we need to install the efene app template to use it later, this only needs to be done once:

mkdir -p ~/.config/rebar3/templates
git clone https://github.com/efene/rebar3_efene_template_app.git ~/.config/rebar3/templates/fn_app

Let’s create a project called myfnapp using the fn_app template:

rebar3 new fn_app name=myfnapp
cd myfnapp

Let’s compile our app:

rebar3 compile

Try it in the shell:

rebar3 efene shell

Try it:

>>> myfnapp_util.hello("mariano")
Hello mariano!
ok

>>> myfnapp_util.add(2, 3)
5

You can quit the shell by calling the q function like this:

>>> q()

Bye!

We can also try the logging version of the hello function, which uses the lager logging library, for that we need to start the lager application before running the function, this needs to be done manually on the shell but will be done automatically by the virtual machine when running an application:

rebar3 efene shell

>>> application.ensure_all_started(myfnapp)
(ok, [syntax_tools, compiler, goldrush, lager, myfnapp])
20:21:49.127 [info] Application lager started on node nonode@nohost
20:21:49.127 [info] Application myfnapp started on node nonode@nohost

>>> myfnapp_util.log_hello("bob")
20:22:11.517 [info] Hello bob!
ok

>>> q()

Bye!

Given that we are good software citizens we test our code, that’s why we want to run some unit tests to be sure that this works:

rebar3 ct

This will compile the tests and run them for you.

In the template one test should fail, open test/{{name}}_SUITE.fn (test/myfnapp_SUITE if you didn’t change the app name) and fix it, then run the test task again:

rebar3 ct

That’s it, now you can make changes, run rebar3 ct again and keep going.