Credo
Credo v1.6.4

View Source Credo.Check.Refactor.UnlessWithElse (Credo v1.6.4)

This check has a base priority of high and works with any version of Elixir.

Explanation

An unless block should not contain an else block.

So while this is fine:

unless allowed? do
  raise "Not allowed!"
end

This should be refactored:

unless allowed? do
  raise "Not allowed!"
else
  proceed_as_planned()
end

to look like this:

if allowed? do
  proceed_as_planned()
else
  raise "Not allowed!"
end

The reason for this is not a technical but a human one. The else in this case will be executed when the condition is met, which is the opposite of what the wording seems to imply.

Check-Specific Parameters

There are no specific parameters for this check.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.