Debug

A simple code inspection tool for development.

Usage

defmodule MyModule do
  use Debug
end

Basic example

Via test/debug_test.exs:

Debug.info("foo")
Debug.info(1..100, limit: :infinity)

Debug.debug("foo")

Debug.alert("foo")

Debug.error({:error, "message"})

Debug.log(["foo", "bar", "baz"])

Debug.warn("foo", nil)
Debug.warn(:foo, nil)

Yields:

Useful example

I made this package so I could inspect values via pipes without losing the context.

With IO.inspect/1:

%SomeStruct{}
|> transform()
|> IO.inspect()
|> transform_again()
|> IO.inspect()

This is fine for quick inspection, but it becomes unwieldy as there is no frame of reference for the output.

With Debug:

%SomeStruct{}
|> transform()
|> Debug.log(:first_transform)
|> transform_agein()
|> Debug.info()

The first Debug.log/2 will prepend :first_transform to the output in addition to the code file and line.

In the second Debug.info/1, the source code is prepended to the output. So matter where the inspecting function is, you can always find your way back to the source to remove or modify it.

You can see below how Debug works around your piped values.

Installation

def deps do
  [
    {:debug, "~> 0.1.0"}
  ]
end