EasyErrorLogger

Makes logging of caught, rescued and unmatched errors easier.

In Elixir, the way to get beatiful error messages with a well-formatted stack trace isn't as straightforward as in other languages, where a single line is often enough to format the error message, the stack trace and also print it to the console.

Usually, you'd have to do something like this:

try do
  handle_foo!()
catch
  e ->
    formatted = Exception.format(:error, e, __STACKTRACE__)
    Logger.error(["I really tried, but this error occurred:\n", e])
end

which is hard to remember. In EasyErrorLogger, it's as simple as this:

# top of module
import ErrorLogger

try do
  handle_foo!()
catch 
  e -> log_message_and_error("I really tried, but this error occurred:", e)
end

This results in the following log message:

[error] I really tried, but this error occurred:
** (TheThrownError) Something went wrong
    (elixir) lib/foo_lib/foo.ex:10 Foo.handle_foo!/0
    (elixir) lib/application.ex:18 MyApplication.start/2

In this single line, EasyErrorLogger has figured out that it can get a stacktrace from __STACKTRACE__, which is not possible outside of catch or rescue clauses.

This means that the same macro can be used for errors that were received from an error tuple:

case handle_foo() do
  :ok -> :ok
  {:error, error} -> log_message_and_error("This didn't work:", error)
end

Note that this way of logging the error message will not include a stack trace. This might be adressed in a future update.

Installation

The package can be installed by adding easy_error_logger to your list of dependencies in mix.exs:

def deps do
  [
    {:easy_error_logger, "~> 1.0"}
  ]
end

Documentation can be found at https://hexdocs.pm/easy_error_logger.