Settings View Source Credo.Check.Refactor.WithClauses (Credo v1.6.7)

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

Explanation

with statements are useful when you need to chain a sequence of pattern matches, stopping at the first one that fails.

But sometimes, we go a little overboard with them (pun intended).

If the first or last clause in a with statement is not a <- clause, it still compiles and works, but is not really utilizing what the with macro provides and can be misleading.

with ref = make_ref(),
     {:ok, user} <- User.create(ref),
     :ok <- send_email(user),
     Logger.debug("Created user: #{inspect(user)}") do
  user
end

Here, both the first and last clause are actually not matching anything.

If we move them outside of the with (the first ones) or inside the body of the with (the last ones), the code becomes more focused and .

This with should be refactored like this:

ref = make_ref()

with {:ok, user} <- User.create(ref),
     :ok <- send_email(user) do
  Logger.debug("Created user: #{inspect(user)}")
  user
end

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.