Elixir Function Decorator

A function decorator macro for Elixir. Used mainly for adding log statements to the function calls.

This project is based mainly on:

The work of Saša Jurić on the Elixir macro articles. Especially the mechanism for extracting function definition metadata.
The solution from him for how to override the def macro in Elixir
An addition made by Björn Rochel to the adef macro considering default values for arguments.

Motivation

All I did was use the solution provided by the mentioned above, add some minor refactoring and adjustments for my needs and package it as an helper module.

This was a learning project getting into Elixir macros field.

For getting into Elixir Macros, you are encourgae to read Saša Jurić 's excellent Elixir macro articles series

State

Currently in alpha stage.
Not intended to be used in production. Only for experiments.
For logging, one can use other means like trace.

Installation

If available in Hex, the package can be installed as:

Add function_decorating to your list of dependencies in mix.exs:
def deps do
```
 [{:function_decorating, "~> 0.0.1"}]
```
end
Ensure function_decorating is started before your application:
def application do
```
 [applications: [:function_decorating]]
```
end

Usage

Decorating in dev with log decorator.

defmodule User do
  use FunctionDecorating
  decorate_fn_with(LogDecorator)

  def say(word) do
    word
  end
end

iex>User.say("hello")
#PID<0.86.0> [x] Elixir.User.say(["hello"]) -> "hello"
"hello"

Default usage is for Mix.env == :dev only. To override it:

defmodule User do
  use FunctionDecorating mix_envs: [:test]
  decorate_fn_with(LogDecorator)

  def say(word) do
    word
  end
end

iex >Mix.env
:test

iex >User.say("hello")
#PID<0.86.0> [x] Elixir.User.say(["hello"]) -> "hello"
"hello"