More guidance for indenting, aligning in case statements.

[raarts]

(I'm taking case statements as an example, but it can be applied elsewhere. Feel free to adjust the title of this issue.)

I feel the style guide can be more explicit about the following:

    case env.method do
      :get -> %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
      _ -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
    end

Now, I find this ugly, so I ended up with this, which I find much easier to read.

    case env.method do
      :get -> %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
      _    -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
    end

And yes, you might need to change adjacent lines when you change the first clause.

It gets more problematic when one of the case clauses is textually long:

   case env.method do
     :exceptionally_long_atom -> %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
     _ -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
   end

or, when aligning:

   case env.method do
     :exceptionally_long_atom -> %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
     _                        -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
   end

The style guide seems to favour (from the examples):

   case env.method do
     :exceptionally_long_atom ->
       %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
     _ 
       -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
   end

Which, to me, is really ugly and not easy to read.

Not really knowing where I'm going with this, just something I bumped into when trying to make my code match the style guide.

[christopheradams]

Lots to consider. As an aside, I'm guessing you meant to format the last example like this:

   case env.method do
     :exceptionally_long_atom ->
       %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
     _ ->
       %{env | status: 405, body: Poison.encode!(%{status: "error"})}
   end

[raarts]

Yes, you're right. Sorry about that. Still think that's ugly though, especially with more clauses.

[christopheradams]

The preferred styles for case statements based on the Elixir code formatter are:

case env.method do
  :get -> %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}
  _ -> %{env | status: 405, body: Poison.encode!(%{status: "error"})}
end

and:

case env.method do
  :get ->
    %{env | status: 400, body: Poison.encode!(%{id: "Sdds"})}

  _ ->
    %{env | status: 405, body: Poison.encode!(%{status: "error"})}
end

Hopefully the latter one addresses your readability concerns.