Basics

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

Explanation

Forbids the keyword form if cond, do: x, else: y (and the unless equivalent) when the expression spans more than one line. Switch to the explicit do ... else ... end block form.

The keyword form is great for tiny one-line conditionals. Once the expression has to wrap across multiple lines, the , do: / , else: punctuation is harder to spot than a plain do block and encourages awkward mid-expression line breaks.

Bad

if Enum.any?(list, &is_integer/1),
  do: List.first(list),
  else: List.last(list)

unless map_size(m) == 0,
  do: Map.values(m),
  else: []

# do-only, still multiline — flagged
if cond,
  do: some_very_long_function_call(arg1, arg2)

Good

if Enum.any?(list, &is_integer/1) do
  List.first(list)
else
  List.last(list)
end

# single-line keyword form — fine
if cond, do: x, else: y
unless cond, do: x

# block form — never flagged
if cond do
  x
else
  y
end

The check inspects every if and unless that uses the shorthand keyword form (i.e. , do: rather than do ... end). Block-form conditionals are not considered.

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.