def get_user  
  case Repo.get_by(User, name: "jon") do
    nil -> User |> Ecto.Query.first |> Repo.one
    repo_user -> repo_user
  end
end

but like the pattern matching one much better..

also be aware of errors if get_by returns more than one record.. so maybe refactor this..

Here unless is being used like a statement - which can result in warnings

FP uses expressions, e.g.:

user = 
  case Repo.get_by(User, name: "jon") do
    nil ->
      User |> Ecto.Query.first |> Repo.one
    result ->
      result
  end

which was already shortened to:

user = Repo.get_by(User, name: "jon") || User |> Ecto.Query.first |> Repo.one

which still is an expression.

with is also an option, thought I’d personally likely use || here

user = with nil <- Repo.get_by(User, name: "jon"), do: User |> Ecto.Query.first() |> Repo.one()